Page 1: DIGITAL CAMERA FEATURES

A digital camera is really not that diferent from a film camera. On a film camera, light is focused by a lens onto a rectangular piece of film. Because different areas of the film are exposed to different colors and brightnesses, different areas undergo different chemical reactions, and so an image is recorded. Once the lens is focused, and the shutter is opened a certain width through a certain amount of time, the shutter is then closed again and the film is moved out of the way to be replaced by a fresh unused one. How much the shutter is open and for how long, along with how much light is outside and how sensitive the film is to it, determines how dark or bright the picture will be.

On a digital camera, light is focused by a lens onto a rectangular CCD sensor. Because different areas of the sensor are exposed to different colors and brightnesses, different areas undergo different ionization processes, and so an image is recorded. Once the lens is focused, and the shutter is opened a certain width through a certain amount of time, the electrical charges induced in the different areas of the sensor by the focused light are "flushed" to a processor that converts them into an image file and then saves that file on a memory card, or in the camera's small internal memory. How much the shutter is open and for how long, along with how much light is outside and how sensitive the sensor is to it, determines how dark or bright the image will be - but you can see how bright the image will be before you take it by looking at the electronic screen on the back of the camera, which is connected to the CCD sensor to show you the "predicted" image in real time. You can also have this screen show you an image file after the picture is taken, so you can see how it looks. And since the CCD can capture images at a high framerate continuosly, most digital cameras can record this data as video, usually along with sound recorded by a small microphone in the camera.

The sensor is smaller than a frame of film, though, so the lens can be scaled down proportionally. Or, if the lens is the same size, it will be gathering more light per area of sensor, so this more intense focusing can allow for the shutter to be open less (which leads to less blur).

How sharp will your image be? That basically depends on two factors: How sharp your lens is (how sharp an image it can project on the sensor), and how harp your sensor is (how much detail it can record if a sharp image is projected onto it). The sensor is made of millions of small photo-sensitive cell clusters, each of which can record the color and brightness of the light falling on it. The more of those clusters you have, the more details you could capture. But, if the clusters are too small and too crammed together, then they start interfering with each other and being thrown off by small signals of light or electricity, which makes the picture look "grainy". So the sharpness of your lens, the number of cell clusters in your sensor, and the grainy-ness of your sensor, are all crucial in determining how sharp the picture is that comes out at the end.

How sharp the lens is has a lot to do with how carefully it is crafted - out of what materials, if any of the elements have aspherical shapes, et cetera. In general, a bigger lens will be much more likely to project an image sharply. So whether a camera's lens is the size of a dime, the size of a quarter, or the size of a small cup, will give you a pretty good idea of how good this lens is at gathering and focusing light. Lenses made by Leica, Carl Zeiss, and other names associated with photography (like Canon, Nikon, Olympus, Fuji, and Kodak) are usually the sharpest. Panasonic cameras have Leica lenses, and some Sonys use Carl Zeiss glass.

The number of cell clusters in the CCD sensor (the "resolution") is measured in megapixels, so that's a dead-easy one. It usually says on the box.

The grainyness of the sensor, although it is as important as the resolution to determining how much detail is captured, is in part dependent on the size of the sensor, and on the resolution of the camera. Smaller sensors, or sensors with more megapixels - in other words, sensors with more pixels per unit area - tend to be grainier. So small cameras, and cameras with 6-8 megapixels, tend to be real grainy. This becomes painfully evident when you make the sensor more sensitive to light (high ISO speed, like 400) for shooting in low light.

(This is the main reason why pictures made by those huge expensive SLR cameras are a lot sharper - their sensors can have as much as 16 times the area of most digital camera sensors, so grain is not a problem at all, even at high ISOs. That, and lenses are typically a whole lot sharper. So an SLR with 6, 4, or even 3 megapixels can take pictures as sharp as those taken by compact digital cameras with twice the number of megapixels).

Let’s start with the megapixels, which are the basic way to measure how sharp your pictures can be. A Pixel (a word derived from “PIX" (short for "pictures") and "ELement”) is the smallest area of a picture with a distinctive color, kinda like a “molecule” of a picture. If you look real close at a TV or at your monitor (especially if it’s an LCD display), you’ll see there are many tiny squares of color making up the image. Each one of those is a pixel. A megapixel is a million pixels. Your computer screen can probably display one MP or so – in other words, if you display a 4-MP image on your computer, there is some detail you just won’t see. A TV image has between one quarter and one half of a megapixel – it gets fuzzy quite fast if you look at it from very close.

So you can have a real good idea of what it means to have more or fewer pixels, check out these three pictures. The images below have 330 thousand pixels (a third of a megapixel), 80 thousand, and 20 thousand. You can see what a low pixel count looks like, when a low-pixel image is shown way larger than it should be. (But remember, you'll never see pixels that big. Even the third-of-a-megapixel image looks fine, so you can KNOW that no image made by a multi-megapixel modern digital camera will ever look as bad as the second and third pictures below).

330,000 pixels ( 1/3 of a megapixel)

82,000 pixels

20,000 pixels

A high MegaPixel count comes in handy when you want to crop pictures, and when you want to make enlargements. For uncropped 4x6 prints, 2 megapixels are usually enough, but for 5x7s and 8x6s, you kinda need to go up to 3 if you want a sharp picture. If your picture will be looked at from a small distance, I’d suggest a 4MP minimum for pictures that will be enlarged to 8x10. Then again, if your picture will NOT be inspected closely (say it is on a wall behind a couch, so no one will get closer to it than a meter or so away), then 8x6s of 2MP images, or even 8x10s if your 2MP camera has a really sharp lens, should be all right, and 8x10s of 3MP images are also definitely all right if no one comes to within 3 feet or so of them. I have a ton of 8x6s on my wall behind my bed. Most are 2MP, a couple are 4MP, and one is a really sharp 1MP (as far as 1MP images go).

I insist that, unless you're making posters, you don't need more than 3 megapixels, maybe 4. Two-megapixel images make fine 8x6s, and don't let the folks at the store tell you otherwise. Below are a bunch of pictures, all taken with two-megapixel cameras. Do they not look sharp? When you click on these thumbnails to open each file, it might look just a tad grainy, but that's because you're blowing them up to the size of a monitor, about 12 inches on a side, and then looking at them from very close. Besides, your monitor can't show detail as dense and fine as a print could .This means these pictures would make fine 8x12s if you're not scrutinizing the 8x12 prints from like a foot away, or looking at then on your computer. And the 4x6 prints made from these pictures are very, very sharp indeed. I don't think anyone needs much sharper pictures than this, unless you're making calendars, having stuff printed on magazines, or trying to sell your photographs. (Pictures taken by 4-megapixel SLRs are used professionally, like on calendars and ads, though, so you REALLY don't need more than 4).

I hope these pictures keep you from blowing a fortune on a super-high-resolution camera. THIS IS A VERY IMPORTANT POINT: Don't buy more megapixels than you need, and don't let the camera companies' marketing departments tell you how much you'll need. Three or four megapixels is all you need, even for 8x12s and for some cropping if you're gonna get 4x6s. Sure, 5MP images might be sharper, but unless you print them out huge, or crop a lot, you never even really get to see all that detail. So if you're thinking about a 5-to-8 MP camera, consider getting a 3 or 4 MP camera instead, one with a sharp lens and a not-too-noisy sensor, or a smaller camera, or one with a bigger screen, etc.

As I mention a few times on this page: How sharp the lens is, and how grainy the sensor is, can affect image quality even more than resolution. So there's much more to it than megapixels. As you can see in the "Don't buy more megapixels than you need" section, a camera with more megapixels can sometimes deliver lower image quality!!! (You can click here to go straight to the comparisons that show this.)

Just as some film pictures sometimes look “grainy”, some digital pictures look “noisy”. I personally call digital-picture noise “grain” just because it looks similar to film grain, has the same effect (loss of detail), and is pretty much caused by the same things (interference when you try to make the film/sensor more sensitive when it has little light to work with). Since grain results in a loss of detail, you can have a high-megapixel camera but take pictures that don’t look sharp if your sensor is really grainy. Unfortunately, there is no easy metric for how grainy a sensor is (the way that the number of megapixels is an easy metric for the resolution). All other things being equal, the smaller a sensor is and the older it is, the more grainy it is. Older cameras, and cameras with smaller sensors, tend to take grainier pictures. Cameras made by certain manufacturers (like most of the the smaller cameras made by Casio, Minolta, Sony and Pentax) tend to be grainier than average. Very-high-megapixels cameras, in the six or eight megapixel range, also tend to take grainy pictures, which means they usually don’t capture any more detail than a 4 or 5 megapixel camera (in other words, don’t waste your money on a high-megapixel camera unless it has a large sensor to keep graininess down).

The only way to know how grainy a camera’s sensor is, is to go online to sites that have reviews for different digital cameras, and look at a picture actually taken by the camera, blown up to full size (one pixel of the picture = one pixel of your screen… This will mean you can only see a small portion of the picture).

As I mention a few times on this page: How sharp the lens is, and how grainy the sensor is, can affect image quality even more than the number of megapixels. As you can see in the "Don't buy more megapixels than you need" section, a camera with more megapixels can sometimes deliver lower image quality due to grain in the camera sensor!!! You can click here to go straight to the three comparisons that show this. Here is my favorite of these comnparisons:

Here's my favorite demonstration of how sensor size has a MUCH bigger impact on image quality than does the number of megapixels: The first picture below was taken three and a half years ago, with an old 2 megapixel big-lens Fuji that I don't even have anymore. (This was back when I used to do aerodynamics research at Stanford. You can tell by the wires and power supplies hanging all over (and through!) the wind tunnel that the electrical-engineering aspect of this work was not my specialty). The second picture (the vertical one) was taken very recently, with my mom's new high-resolution pocket-sized Casio. I hope you can see that I am about the same "size" on both pictures:

Now here are crops of these images to show just my face. Which one is grainier? Which one is sharper? Which one shows more detail?

As you can see, the super-compact Casio's image is quite a bit grainier, to the point where you can't see much of the details of my face (such as, say, the bumps and curves of my ears, or the whites of my eyes, which are much easier to make out on the older picture - well, I guess I did kinda close my eyes a bit on the second picture, but still, you can see the difference). This means a four-year-old big-lens Fuji with TWO MEGAPIXEL resolution takes sharper pictures (images with less grain) than a brand new high-resolution pocket-sized Casio. I hope this demonstrates that the size of the sensor (which you can guess just from the size of the camera) has a MUCH bigger impact on image quality than how many megapixels the camera has or how new it is. And I even locked the ISO on my mom's Casio to the minimum setting (50) to keep grainyness down! (The next paragraph explains what that's about).

If your camera has a small sensor and/or a very high megapixel count, then the only way to keep grain down is to use low ISOs. The ISO, or “film speed”, determines how sensitive your film or sensor is to light. When you buy film, you typically buy a roll of 200-speed or 400-speed film (or maybe 50, or 800, or 1600…). The higher this number is, the less light you need to take a picture (so higher-ISO is better for indoors and/or night shots), but the grainier the picture is. On a digital camera (even many of the ones with no other manual controls), you can alter the ISO. Keeping it low (like 100, unless your camera can do lower like 80 or 50 which is even better) will minimize graininess. Cameras with large-ish sensors can usually go up to 200, or maybe even 400, and take pictures without a lot of grain, but if your camera has a small sensor (especially if it is old) or lots of megapixels, I would advise not venturing beyond 100 unless it’s night and you have no choice.

Here’s what I mean. The following six pictures were taken at ISO 50 and ISO 400 on my Panasonic (which has a tiny sensor). The grainier picture replicates the grainy appearance of pictures taken by older and/or cheaper digital cameras. The last 3 pictures were taken at ISO 400 on my 10D, which has a sensor about 8 times bigger. Notice how it is not nearly as grainy.

The above picture shows my stove as seen by my FZ10 at ISO 50.

In the crops below, notice the details such as the horizontal lines by the burner control knobs:

The next picture, and two crops from it, were taken from the same spot at higher ISO (400). Notice how much detail is lost when the grain gets bad:

Above, notice how the little horizontal lines on the stove (around the burner control knobs) are practically GONE. No subtlety of detail here, no texture. Small sensor + high ISO = crappy, grainy, noisy picture with severe loss of detail, that's the whole point I'm trying to make. (Although some Fujis and a couple Sonys do manage to take pictures at High ISOs without losing too much detail and without excessive grain/noise).

But I also have a camera with a sensor 8 times as big, which at the same ISO (400) is still not very grainy. (THIS, my friends, is why one gets an SLR. The resolution in megapixels is not that high, but you get a lot more out of that resolution. The fact that the sensor is much, much less grainy means you get sharp pictures when the lighting is less than perfect, which is not true for most non-SLR digital cameras).

Ah, look, the little horizontal lines are back.

Remember,the only way to know how grainy a camera's sensor is would be to visit sites like DigitalPhotography Review, DigitalCamera Resource, and Steve's Digicams, and look at full-size pictures taken with the camera you are thinking of buying. So I highly recommend doing that.

As I've said, the sharpness of the camera lens is a very strong determining factor in the camera's resolution, every bit as important as the resolution. A high-megapixel, not-very-grainy sensor is no good if the glass in front of it gives it a fuzzy image. Unfortunately, like grain, there is no easy way to measure how sharp a lens is. (Well, there IS a way, the MTF, or Modulation Transfer Function, but this is a bit beyond the scope of this guide, and is seldom used to evaluate non-SLR lenses).

Like with grain, some manufacturers (Minolta, Casio, Pentax) tend to make lenses that are fuzzier than average. On the other hand, lenses made by Leica (found on Panasonic cameras), Carl Zeiss (found on some Sony cameras), Canon, Nikon, and Kodak tend to be quite good.

The best way to know if the camera that you want has a fuzzy lens is to go online to sites like DigitalPhotography Review, DigitalCamera Resource, and Steve's Digicams, and to take a look at full-sized pictures taken by the camera you are considering. You will then be able to tell how fuzzy the images look up close.

As I mention a few times on this page: How sharp the lens is, and how grainy the sensor is, can affect image quality even more than the number of megapixels. As you can see in the "Don't buy more megapixels than you need" section, a camera with more megapixels can sometimes deliver lower image quality due to a fuzzy lens!!!

Here is my favorite demonstration of this (which you can also see, along with others like it, in the "Don't buy more megapixels than you need" section): Jeff Keller, of the Digital Camera Resource Page (dcresource.com), once took two pictures of his house, one with the Panasonic FZ3 and one with the Minolta Z3, as part of the standard shots he takes with every camera for the purposes of comparison and evaluation. Both are large big-zoom cameras with huge quite fast lenses and equivalent focal lengths that go up to around 400mm. The Panasonic FZ3 has 3 megapixels, the Minolta Z3 has (despite what its name may suggest) 4 megapixels. The shot of his house taken with the 3-megapixel Panasonic can be found at http://www.dcresource.com/reviews/panasonic/dmc_fz3-review/houseshot.jpg , and the shot taken with the 4-megapixel Minolta can be found at http://www.dcresource.com/reviews/minolta/dimage_z3-review/houseshot.jpg , and you can see links to (and crops from) these shots here. The shots both look about the same, but if you blow them up and look at, say, a section of wall over his window, you see this:

Quite a difference, isn't it. What's surprising is that the first shot, the nicer one, was taken with the three-megapixel camera, and the second shot, the blurrier one, was taken with the four-megapixel camera. Both were large, big-lens cameras. The Minolta's fuzzier lens failed to capture the texture of the wall the way the Panasonic could. (To be perfectly honest, this could also be the result of excessive noise reduction on the Minolta, but in this case I am fairly sure it's not. Noise reduction is usually cranked way up on many modern high-resolution (i.e. very grainy) digital cameras).

Remember,the only way to know how sharp a camera's lens is would be to visit sites like DigitalPhotography Review, DigitalCamera Resource, and Steve's Digicams, and look at full-size pictures taken with the camera you are thinking of buying. So I highly recommend doing that.

Here I explain what this means when a lens has things like "6-72mm", "39-390mm equivalent", or "3X zoom" written on it. But let's start with "Optical Zoom" versus "Digital Zoom".

What the OPTICAL zoom tells you is how good the lens is at enlarging the center of the image, making a small area look real big, helping to make far-away things look closer. Now, DIGITAL zoom is just real-time cropping, it saves only the middle of the picture without blowing it up first.

What digital zoom does is, it crops the picture in real-time and only records the pixels near the middle. In other words, it takes a few pixels and blows them up. This looks awful. Besides, it’s something you can do later on your computer (cropping). For all these reasons, you can IGNORE what a camera claims it can do with digital zoom. Digital zoom is BS, plain and simple. It's real-time cropping. Optical zoom, however, actually enlarges the subject in the middle of the picture, so that a smaller area of the image actually is made of more pixels, so detail is gained instead of lost.

Digital Zoom: takes fewer pixels and blows them up into bigger area (BAD – Less Detail)
Optical Zoom: takes more pixels to define a smaller area (GOOD – More Detail)

For example, take the three images below. One is a wider-angle shot. The next one uses digital zoom to “enlarge” the tower in the distance, and the last one uses actual optical zoom so you can see more detail of the tower. I swear to God I took those three pictures standing on the same spot, with my FZ10. If you don't believe me, go to your local camera shop and try out a camera with 10- or 12 X zoom.

A park in San Jose.

Above, we zoom into the picture of the park in San Jose using digital zoom.

Below, we zoom in using optical zoom. Can you see the difference? Can you see that digital zoom is essentially useless? Good.

So IGNORE DIGITAL ZOOM. ONLY PAY ATTENTION TO THE OPTICAL ZOOM.

You can see this is a touchy subject for me. I hate to see people say "Oh, 3x optical zoom times 4x digital zoom means this camera has 12x zoom". NO! MY camera, MY huge Panasonic, has 12x zoom. THIS little toy here has 3X! (Sorry. I'm a big-lens snob. I try to suppress this in this guide. Starting now).

In any case, any good digital camera will have at least a 3x optical zoom. Unless otherwise noted, every camera on this guide (page 2) has 3x optical zoom.

Optical zoom can be measured by the equivalent focal lengths of the lens. Most lenses say something like "7.9-23.7 mm" or "35-105 mm equivalent" on them. Basically, the equivalent focal length of a lens (in milimeters, "mm") tells you the field of view of the lens. A short equivalent focal length means a wide field of view, for taking pictures of big crowds/groups or of the insides of rooms (wide-angle lenses are usually around 20mm equivalent, fish-eye lenses around 10mm equivalent), a long equivalent focal length means a narrow field of view, for taking pictures of small and/or far-away things (big zoom lenses are usually equivalent to 300, 400, or 500mm).

Most digital cameras have their widest focal length around 35mm equivalent, some go as wide as 28mm equivalent (which is as wide as you'll need for day-to-day use), some only go as wide as 39mm equivalent (a little zoomed in for most people's taste, but still ok for everything except group shots and wide shots of the inside of a room). With an adapter - sometimes made by the same company that makes the camera (Nikon, Canon, Sony), sometimes by another company (Raynox) - you can make your field of view even wider. I, for example, have a Raynox adapter that brings the widest field of view of my Panazonic FZ10 from 35mm equivalent to a wonderfully wide 18mm equivalent - this allows me to take great indoor shots and great group shots, and to capture wide panoramas with a single picture. On the other end of things, most cameras only zoom as far as about 100 or 120mm equivalent. Some zoom as far as the 200 or 300 range, and a handful zoom beyond 400mm equivalent.

The number associated with the optical zoom - like "3X zoom" is just the focal length with the narrowest field of view divided by the widest one. So if your camera can go as wide as 35mm and can zoom in to 105mm, then 105 divided by 35 gives 3, so "3X zoom". Usually, 200mm of zoom is about "6X zoom", 400mm-equivalent is about 12X, and so on. Below are some examples of this:

Above, a wide angle shot taken at an equivalent focal length of 18mm. That would be "0.5 x" on most digital cameras - you need either an SLR or an adapter to go that wide. This was taken using an FZ10 with a Raynox 0.5x adapter.

Above, a picture taken from the same spot as the first one, at about 33mm equivalent (same minimal equivalent focal length as most digital cameras - which is a shame, cuz the wide-angle allows you to see a lot more, but oh well).

Above, a picture taken from the same spot as the others, at about 100mm equivalent. This is as far as a "3x zoom" lens will get you.

Above, a picture taken from the same spot as the others, at about 200mm equivalent, which is usually equivalent to 6x zoom. Few cameras have 6x zoom, but I think it's worth it.

And finally, a picture taken from the same spot as the others, at about 400mm equivalent, which is usually equivalent to 12x zoom. Dude, look at all that zoom! Isn't it awesome? I can't live without all that zoom. You can get so close...

And why do I keep saying "equivalent"? Because the correlation between the focal length and the field of view was standardized when film cameras were the norm. On any film camera, any 50mm lens gives you the same field of view as any other, and any 28-105mm lens would give you the same zoom range as any other, for example. So it's nice to be able to carry that over to digital cameras, so that a photographer can know how much a lens zooms out or in just by looking at those numbers. Problem is, digital camera sensors are smaller than film, so they only record the middle of the image - they're more "zoomed in" if using the same lens. For example, say I have a film camera with a zoom lens set at 50mm. Say I take a picture. Now say I replace the film with a digital camera sensor that is one sixth the size of the piece of film, so it will only record the middle 1/6 of the image. This picture will look a lot more zoomed in - six times more zoomed in, to be precise - so the 50mm lens acts like a 300mm lens on this tiny sensor, so it's "300mm equivalent". If all you have is the digital sensor, that that 50mm lens is effectively a 300mm zoom lens. So you write "300mm equivalent" on the lens so that people know it can zoom in a lot, even though it is in reality a 50mm lens. Or, look at it another way: Say you take a piece of film and a lens that can do 36-420mm. Now, say you make the film AND the lens on sixth the size. The minituarized lens, since it is one sixth the size as before, now has focal lengths of 6-70mm (one sixth of 36-420mm). But the same image is recorded on the sensor (which acts like a piece of film one sixth the usual size) as would be recorded by a real 36-420mm lens onto a normal full-sized piece of film, so the 6-70mm lens on the tiny sensor is equivalent to what a 36-420mm would be on a film camera.

Aperture is the other aspect of the lens you need to worry about. Most lenses say something like "f 2.8" or "f 2.9 - 3.7" on them. This is the maximum (widest) aperture. If you see one value, then this is the maximum aperture at all the equivalent focal lengths that this lens can pull off. If you see two numbers with a dash between them, then this is the widest aperture at each end of the zoom spectrum (so a "f2.9-3.7" lens can do f2.9 if you're not using the zoom, but only f3.7 if you're zoomed in all the way).

The aperture number is the denominator of the fraction of the focal length that corresponds to the width of the diaphragm. Yes, I know that made no sense at all. Here's what I mean: Say your focal length is 8.4mm, and your aperture is f2.8. This means that the diameter of the circular opening made by the diaphragm is 3mm (because 8.4mm divided by 2.8 is 3mm). The smaller the aperture number, the wider the diaphragm can open, the more light the lens can let in, and the better your pictures tend to look.

(For example, if your focal length is 8.4mm, an aperture of f2 gives you a diaphragm opening 4.2mm wide (since 8.4mm divided by 2 is 4.2mm, which is better (bigger opening means more light) than the 3mm you get at f2.8). But if your focal length is 8.4mm and your aperture is f4, then you only get an opening 2.1mm wide, so you get less light. As you can see, you want the aperture number to be low, which means your shutter opens wide).

And one more thing: The amount of light that goes in depends on the AREA of the opening, which varies proportionally to the SQUARE of the diameter. This means that an aperture of f5.6, when compared to an aperture of f2.8, lets in ONE FOURTH as much light, rather than half as much.

As will be discussed later in the “Tips On Picture-Taking” section, the two basic variables that control how much light make it into the camera are Aperture and Shutter Speed. Aperture is how wide the diaphragm opens (relative to the focal length), and Shutter Speed is how long it stays open for. The wider the aperture (the smaller the f-number), the more light goes in. This allows you to use faster shutter speeds (less motion blur) and lower ISOs (less grain), so a wide aperture (a “fast lens” with a low f-number) is always desireable. It is especially desireable at night (less light usually results in more motion blur due to slower shutter speeds, and in more grain due to higher ISOs) and when you’re using a lot of zoom (any shake on the camera causes significantly-magnified motion blur, so you want fast shutterspeeds when you use the zoom... except unfortunately the aperture is usually WORSE at the zoomed-in end, which is why using a lot of zoom in low light is very hard). A wide aperture is the difference between a fuzzy, motion-blurry, “shaky” shot (usually one taken at night and/or at high zoom), and a nice sharp one. Additionally, high apertures give you nice, arsty, shallow depths of field (subject is in focus but other things are blurry).

Most lenses can get as wide as f 2.8. Some cameras (ahem Casios ahem) only go as wide as f 6.6 (boo!) especially when at max zoom. A GOOD zoom lens is one that stays at f 3.7, or maybe even f 2.8, when zoomed in fully. Some big cameras (Canon G6, Panasonic LC1, Olympus C5050, Sony F717) go as wide as f 2.0 or even 1.8 (wow!), which makes them very fast lenses indeed. If you have an SLR, even faster lenses are available, with apertures of f 1.4, or even f 1.2 if you need to go REALLY fast. Rangefinder lenses with apertures of f 1.0 are not unheard of, but they are not that sharp and are not really practical in the digital age when you can have image-stabilization (allows for slower shutter speeds (and thus lower ISOs) without the shake), and of course we today have Photoshop to make things brighter when the picture comes out too dark.

Image Stabilization is AWESOME. You might think it’s just some fancy feature that will not make a difference. But I'd disagree. Especially on indoor photography, it makes a HUGE difference. Here’s why:

So camera shake is the leading cause of image blurriness, closely followed by high ISOs used to try to fight camera shake by allowing for faster shutterspeeds. (More about this on the part of Page 3 about Manual Controls). So it used to be that the only way to get real sharp pictures in low light was to have a “fast” lens – one with an aperture so wide it lets in plenty of light even when the lighting is poor, thus allowing for reasonably low ISOs as well as reasonably fast shutterspeeds. But fast lenses need to be manufactured more precisely, and require more material, and so are very expensive. BUT, if the camera could simply be kept from shaking, then a slower shutterspeed would not lead to motion blur, and enough light would go in to allow for lower ISOs. Tripods are great for this. But what if you don’t have a tripod?

Enter image stabilization. Image stabilization actually moves the lens to keep it pointing in the same direction while the camera shakes! (Canon calls it IS, which is what I call it since everyone I know shoots Canon, and since I also shoot Panasonic and they also call it IS. Nikon calls it VR for “vibration reduction”, Minolta calls it “Anti Shake”. Same idea). The IS system consists of three or more accelerometers which allow it to know the changes in the camera’s angular velocity in the axes that are not along the centerline of the lens. In other words, if your hand twitches to the right, the camera senses this and points the inside of the lens a little bit to the left, so that the lens keeps looking in the same direction. (Minolta moves the sensor, actually, but all other manufacturers move the lens).

IS is not perfect. It will not suddenly allow you to shoot at ridiculously slow shutterspeeds indoors, or make every dimly-lit scene amazingly rich in detail. But if you keep getting blurry or grainy pictures when it’s dark, IS will help. And if you already get pretty good pictures at slow shutterspeeds, IS will allow you to go slower, or to get even sharper pictures at those shutterspeeds. A steady hand (or, rather, two) is still an important skill for a photographer to have, especially one who shoots in low light. IS can supplement and enhance that skill, but will not replace it. In any case, it’s an improvement over NOT having IS.

And since any camera shake gets magnified when you use the zoom, most cameras with more than 6x optical zoom would get very blurry pictures indeed if they do not have either a very fast lens (Panasonic, Fuji) or IS (Canon, Panasonic, most Minoltas, and some Nikons). (Yes, notice that Panasonic’s Lumix cameras have both IS and a fast lens, making their big-zoom pictures the sharpest around. Their lens is also exceptionally sharp, period, which is noticeable even at minimum zoom as you can see in the “Lens Fuzzyness” section above).

Want proof? The Panasonic reviews you can read at dcresource.com (FX7, FZ20, FZ5) have excellent comparison shots with IS on and off. Check them out. For example, here is a pair of pictures that really illustrate the kind of difference IS can make at slow shutterspeeds:

Above, IS off - what you would normally get if you use slow shutterspeeds, if the lighting is poor, if you're indoors, if you use the zoom a lot, etc. Below, turn IS on and watch the difference. (Images from here).

Can you see the difference? Being able to get away with shutterspeeds this slow (in this case, 1/13 of a second, but you can go as slow as 1/4 or 1/3 of a second) without the blur should allow you to use lower ISOs and thus also prevent the grainy look you would otherwise get when you take pictures indoors or in low light.

When a digital camera takes a picture, this digital picture is stored in a memory card. There are a few kinds of memory cards. They all work the same way, but are shaped differently so each camera can only use one or two types of cards. Compact Flash cards are big and square and are used by most large cameras (except Panasonics, which use SDs). Secure Digital cards are small and rectangular, and are used by most small cameras (except some Canons, which use CFs). XD cards are small and have one side curved out, and are used by Fuji and Olympus cameras (some big Fujis take CFs as well). Memory Sticks are elongated rectangles used by Sony cameras (some small Sony cameras use Memory Stick Duos, which are smaller and look like SD cards, and can be turned into regular Memory Sticks if placed in an adapter).

CF and SD cards are cheapest, xD cards and Sony Memory Sticks are most expensive. However, these price differences will not be very big, so I would not recommend you choose a camera based on what kind of card it takes (unless you already have a ton of memory in the form of one kind of card, and want a camera that will allow you to use those cards). Just make sure you get the right kind of card for your camera.

How much memory fits in one card is measured in MegaBytes of memory. They usually range from 64 Megs to 1 GigaByte (1024 Megs), and some CF cards (which actually have little hard drives in them, MicroDrives) go up to 6 Gigs (that's more Gigs than some iPods have).

A picture will take up roughly one Meg of memory for every three MegaPixels. So if you have a six-MegaPixel camera, that’s about two Megs per picture, and the 16 Meg card the camera comes with should hold about 7 or 8 pictures… A one-Gig card, though, will hold about 500 pics taken with this 6-megapixel camera.

That is:

Size Of Card in MegaBytes, times three, divided by Camera Megapixels, will tell you how many pictures it will hold, roughly.

I say "roughly" because pictures can be compressed more or less. Compression is when you take a picture and keep its MegaPixel count, but lose some detail in order to make the fize size smaller (so more pictures fit on the card, or are easier to email). You can double the number of pictures on a card by compressing them more. Compression settings are usually called "Fine" or "Sharp" if you don't compress a lot, or "Rough" or "Poor" if you do. Some cameras can take pictures in RAW or TIFF formats, which is when no compression goes on at all (or the compression is "lossless", i.e. done carefully enough so that no detail is lost, which still results in huge huge file sizes). This way, every last bit of detail is preserved, but the pictures will be a few Megs each, or MANY Megs each for a high-MegaPixel camera. If you're not a professional photographer, there is no need for this. But do stay away from high-compression settings, despite how many more pictures they allow you to fit on your card. Many crappy, blurry pictures is NOT better than half that many, but much sharper, pictures.

(Besides, one-Gig cards can be found these days for relatively affordable prices - I think the ability to take hundreds of high-quality shots without worrying about memory is worth the price of one or two Gigs of memory).

The two pictures below should show how extreme compression can ruin a picture. Note the dot-like compression artifacts everywhere, and all the rectangular areas... These can make a person's face unrecogniseable...

Above picture by Gar Travis. The picture below, I over-compressed later to make a point. Let it not be indicative of Gar's skills or of the amazing sharpness than can be captured by my FZ10, which he was using at the time. Notice I'm holding my then-new 10D.

Ugh. I hate lossy compression. Keep your image quality settings high to avoid shots like that one. You might see this and think - Well, DUH! But when I worked at Wolf Camera, we did get digital pictures like this every now and then, and the confused "photographers" would think there's something wrong with their cameras... or, worse, look at their prints and say "Y'know, digital pictures just aren't as sharp as film"... GRRRR!!! (Sorry. Quick flashback to my frustration at my customers' stupidity).

One last thing to remember about memory: Some cards are "faster" than others. If you want to shoot lots of pictures in quick succession (burst mode), and if your camera can shoot very large pictures very fast, you might need a fast card to be able to record these pictures as they're being taken. Also, if you're shooting large videos with your digitcam, you might need a faster card. Otherwise, you don't need to worry about card speed. Since few people use their camera's burst mode (you're usually blind during burst-mode photography unless you have an SLR) or take huge videos, this is probably not something you need to worry about.

Most cameras today can record digital movies, with sound. Some can record movies that are about as good as those made by a camcorder.

You may think that this ability to shoot video is a useless feature, but once you get yourself in the habit of taking little digital videos of funny and spontaneous (or just memorable) moments, you won’t regret it. It’s like taking video snapshots. If you restrict them to a few seconds, most of these videos will be small enough to send over email. Also, you can burn then to VCDs or DVDs if you have the proper software and hardware.

Most digicams these days can shoot video at 640x480 resolution and at 30 frames per second, which is about the same as the video displayed on a non-digital non-HD television. If the resolution or framerate is any lower, your video won't look great (it will basically look like the videos you see on YouTube and Google Video; Not quite sharp and sometimes jumpy rather than smooth).

Most digital cameras allow you to pick between a couple different video resolutions and frame rates. Some even allow you to compress your video more or less. A smaller resolution (typically 320x240), a higher compression setting (like MPEG4), and/or a lower framerate (like 20 frames per second, 15 fps, or 10 fps) will make your video file much smaller, making it easier to email, store, transport, upload/download, etc. So if you don't need video shot at camcorder quality, then reducing the resolution and/or increasing the compression is recommended. Decreasing the frame rate usually makes videos look jumpy and not that fun to watch, though, so I recommend keeping that as high as you can, ideally no lower than 20 fps.

One other thing to keep in mind is whether you can use the zoom while shooting. Only a handful of cameras allow you to zoom in and out while recording video (this is because you can sometimes hear the whirring of the zoom motor in the video when you use the zoom). On most digital cameras, once you start recording, the zoom is "locked", so make sure you're zoomed to the desired focal length when you start.

(The cameras that allow you to zoom in and out while recording video are the pocket sized Kodak V570, V603, and V610, the medium-sized (but with 10x zoom!) Panasonic TZ1, the fairly big Minolta Z6 and Canon S2-IS and S3-IS, and the really big cameras with mechanical zoom rings like the Panasonic FZ50 and Fuji 9000 and 9100).

As I mentioned earlier, if you do want to shoot 640x480 30fps video, this video means a lot of data being recorded FAST (your camera is taking 30 pictures per second and has to record them onto the card). This means you probably need a fast card in order to be able to shoot video of this high quality. That is, UNLESS your camera shoots MPEG4 video, which means the video is compressed into much smaller data sizes without a noticeable drop in quality. MPEG4 video files are so small, you can shoot them with a card that is not very fast. However, very few cameras can encode MPEG4 in real time.

Most digital cameras are powered by rechargeable lithium-ion batteries. It’s like a cell phone or a power tool or anything else that has its own battery – you usually have a charger that the battery goes into for a while to charge, while the charger is plugged into a wall power socket. In some cases, you can plug the camera itself to the wall socket and the camera acts as the charger. The important thing is, if you’re out on a hike or on a drive or a trip or something and your rechargeable battery runs out… you’re screwed unless you have a spare one in your pocket. Given Murphy’s Law and its corollary pertaining to how one WILL forget to charge one’s camera’s rechargeable batteries before being away from a wall socket all day… it’s a good idea to buy a spare one, so that if (no, WHEN) the rechargeable battery in the camera runs out, you can just take the other one out of your pocket and swap it. The only problem is, each camera (or each family of digital cameras) has one specific model of batteries for it – again, like cell phones – and they can be expensive (like $20-70). Still, do get another one.

Or avoid this problem by getting a camera that is powered by AAs, a GREAT feature. If you do, then you have the option of getting rechargeable AAs and having the best of both worlds – using the same batteries over and over, AND being able to buy one at the neaby gas station if your rechargeable AAs run out.

Most digital camera batteries last for about 200 pictures if the LCD screen is on, or about 400 if the screen is off. Some cameras, like Casios, have particularly good battery life, and others, like Fujis, do tend to drain batteries kinda quickly. But 200-400 shots is usually what you'll get with any digicam.

A lot of people, when choosing a digital camera, say:

"I want it to take good pictures in low light", or
"I want to use it to take pictures at concerts", or
"I want to be able to take good pictures at my kids' basketball games", or
"I want to take good pictures at parties", or
"I want to be able to get good pictures of evening games", or
"I want to be able to get good shots at my kids' plays",
et cetera.

Also, a lot of people get digital cameras, and then are surprised at the low quality of their low-light pictures, and want to know how to improve it, or what to look for in a camera where the low light image quality will be better.

Low-light photography is the most challenging kind of photography. Photography is all about capturing light, so if you don't have a lot of light to work with, it will always be much harder. There is no easy or cheap way to guarantee you'll get good pictures in low light. A low-light environment is the situation where really good photographer skills, and really good equipment, really make a major difference. Any dummy with any cheap digital camera can take beautiful pictures outside on a sunny day. But it takes a careful person, and a good camera, to capture shots when you have less light to work with.

The tips on this section should help, though.

Let's go back to the basics for just one second. A picture is recorded when a shutter is open for a little while, which allows a lens to focus some light onto a sensor. How bright the picture will be depends on:
-How much light there is outside,
-How much light the lens can gather (aperture),
-How sensitive the sensor is to light (ISO),
-And for how long the shutter is open (shutter speed).

This means that if you have very little light to work with, one (or more) of the following will be true:

-You're gonna need to make your sensor more sensitive to light (increase the ISO),
-You're gonna need to leave the shutter open for longer (slow down the shutter speed),
-You-re gonna need a lens that gathers more light (wider aperture),
-You're gonna need more light illuminating your subject (use the flash).

If your subject is close, using the flash usually solves the problem. However, if the subject is more than 15 or 20 feet away, this usually does no good. And even when the subject is close, using the flash leads to the colors on the subject being all washed out and the background becoming completely black, which is usually not desireable if you can help it. So, for the rest of the section, I will assume you do not want to use the flash (because yoru subject is too far away or because you don't like the way pictures look when you use the flash).

Aperture: Usually, you already take pictures with your aperture wide open, so that the shutter is open for as little time as possible and motion blur is minimized. So, when it gets dark, you're not going to be able to go much wider. If you know you'll want to take pictures indoors, get a camera with a "fast" lens - this means the aperture can go extra-wide. (Wide-aperture lenses are said to be "fast lenses" because they gather more light and thus allow for faster shutter speeds to be used, so images look less blurry). At the end of this section, I will list some cameras that have exceptionally fast lenses, some of which will allow you to shoot with shutter speeds three to ten times faster than normal digital cameras (so you get one third to one tenth the motion blur). These are usually a little expensive, but fast lenses always are.

ISO: Making the sensor more sensitive to light will allow you to use faster shutter speeds and thus minimize motion blur and camera shake. Cameras make use of this resource when lighting is poor. However, increasing the ISO also makes the pictures more grainy because of increased sensor noise. So you really should not raise the ISO any more than you really have to. Therefore, the important thing when shooting in low light (as I am about to describe in detail) is to figure out the slowest shutter speed at which you don't get too much blur, so that you get as much light in as you can and thus the ISO only has to go up the minimal amount.

Shutter speed: This is where good photographers and/or good equipment can make low-light situations much easier to work with, and where bad photographers and bad equipment take pictures that look awful. Knowing how to deal with slower shutterspeeds will make or break your low-light shots. One recommendation is to get cameras with image stabilization. The main problem with slow-shutterspeed pictures is that your hand usually moves just a little bit whilethe picture is being taken. If the shutter is open for longer, that leads to blur. BUT what image stabilization does is, it senses that the camera is moving, and actually moves the lens the opposite way! This means the lens keeps pointing the same way even if the rest of the camera shakes, therefore slow shutterspeeds will cause much less blur than they normally would. IS (image stabilization) can lead to drastically improved low-light pictures. But, still, the big question is, how slow CAN you shoot? I mean, it seems clear that there is some minimum speed where, if you shoot slower, you get motion blur. The thing is, if you shoot faster, then you get less light, and so the camera has to increase the ISO, and the picture ends up coming out grainy. So yes, it is VERY important to figure out your minimum speed and stay at it, so that the pictures are neither blurrier nor grainier than they have to be. Yeah, ok, but what is that minimum speed!? Well, it's a function of the equivalent focal length. The more you zoom in, the more magnified the shaking of your hand becomes, and the faster you have to shoot. The general guideline is: The slowest you can go is your equivalent focal length (in mm, as a fraction of a second). What I mean is: If you're zoomed all the way out, then your equivalent focal length is something around 28mm to 38mm, right? So shooting any slower than 1/30 of a second will probably make for a blurry picture. If you zoom in all the way with your 3x zoom lens, then the equivalent focal length is around 100mm, so shooting any slower than 1/100 of a second will probably cause noticeable blur. If you have a 12x zoom lens (equivalent to around 400mm), then you probably don't want to shoot any slower than 1/400 of a second when you zoom all the way in. This is, of course, just a general guideline based on how much most hands shake and how much this shake gets magnified when you zoom. If you have steady hands (or if you follow the tips in the next paragraph), you can shoot even slower than your focal length. Conversely, if you have shaky hands, you might want to shoot a little faster than your focal length, like one and a half times the focal length (when zoomed all the way out at 30mm, shoot at 1/50 of a second, and when zoomed at 3x at 100mm, shoot at 1/160 of a second, for example, which will decrease the blur but require either a faster lens or a higher ISO so that the picture does not look too dark). Ah, and image stabilization allows you to shoot two to four times slower: At 35mm, you can take pictures at 1/10 of a second, maybe even as slow as 1/8, which will let in PLENTY of light. At 100mm, you can probably get away with shooting at 1/30 to 1/60 of a second, maybe as slow as 1/25. At 400mm (using that 12X zoom), you can probably shoot at 1/160 of a second, give or take, if you have good image stabilization. Again, remember you want to shoot as slow as you can (without getting shake-blur), so that more light enters the camera, and you don't have to crank up the ISO sensitivity (which leads to grain).

I said "1/160s, give or take" because depending on whether your hands are shaky or steady, you may feel comfortable shooting even slower, or you may feel you need to shoot faster. Here are some tips for shooting at slower shutter speeds:

-Use two hands! One on the right side of the camera, the other either on the left side or under the lens.
-Rest your elbows on your chest instead of sticking them out to the sides. That way, your arms wobble less, since your torso will help steady your arms.
-Use the viewfinder instead of the LCD. You know how, a lot of the time, you take pictures by looking at the screen on the back of the camera, holding the camera out in front of you? That's bad in low light. If your camera has a viewfinder (the little thing you look into, like on film cameras), use it! And press the camera a little bit into your face if you can, like into the nook between your nose and your brow. That will make slow shots a lot steadier, trust me. Squishing the camera hard into my nose helped me tremendously with slower-shutterspeed shots.
-Hold your camera gently with your fingers or fingertips, don't gove it a death grip with your whole hand. You may be surprised at how much less the camera shakes when held gently, compared to when it is held strongly.

After some trial and error, you should be able to say "I can comfortably shoot at around two thirds or three quarters of my focal length", or some such fraction. Remember that fraction. Knowing how slow you can go as a fraction of your focal length will allow you to always use the slowest shutter speed you can, which will prevent noticeable motion blur but will keep the ISO from being higher than it needs to be (and the picture from being grainier than it needs to be). Someone who is familiar with their grip on their camera, and/or with their image stabilization system (if any), should have a good idea of the speeds they can photograph at, and this will allow their low-light pictures to be as good as possible. This is why I said you have to put some thought and effort into it if you want good low-light shots. It's simply not as easy as daytime photography.

Shooting at these slow speeds may STILL not make the image bright enough. If that is the case, then you might still need to raise the ISO after all. But know that, if you are shooting as slow as you can confidently go, then your ISO is not being raised any more than absolutely necessary.

If you have a fast lens or if your camera does well at higher ISOs, then you don't need to shoot at these harder super-slow speeds. And if you have image stabilization, shooting at these slow speeds and not getting blurry shots is easier. So here are some cameras with fast lenses, good high-ISO performance, and image stabilization so that you can know which cameras can take good indoor shots:

First, the high ISO. It used to be that digital SLRs all had great high ISO performance, and fixed-lens digital cameras all took horrendously grainy pictures if the ISO was not set at the minimum level. While all digital SLRs still excel at high ISO performance, some of the normal fixed-lens digital cameras now are also good at that. Fuji has developed some truly fantastic high-ISO technology for their sensors, so Fuji's newest digital cameras do a LOT better in low light than any other. I mean, they do as well as SLRs! It's almost unbelievable - if you don't believe me, Jeff Keller has taken many pictures and shows you just how well the cameras perform at high ISOs on his pages about the Fuji F10, Z1, and S5200. There are even newer, better verions of these cameras, all of them good at high ISO (the Fuji Z3, F11, F20, F30). These cameras kick butt in the high-ISO realm and leave all others (except SLRs) in the dust. Ah, wait, there's one more. It used to be that Sony's cameras took really grainy pictures (especially their 5 megapixel cameras), but I guess Sony got tired of hearing people complain about this when they made the new T9 and the W100. These pocket-sized cameras take pictures with very little grain, even at high ISOs! Not only that, the T9 also has image stabilization. Definitely the pocket-sized cameras to have in low-light situations. However, if you want reliably good low-light shots, the outstanding high-ISO capabilities of most digital SLRs (and the super-fast lenses you can get) are still the surest way to get good low-light shots.

Now, the fast lenses. Only a handful of cameras are any faster than f2.8. Also, when you use the zoom, the maximum aperture almost always gets a lot worse - and those are the times when you need faster shutter speeds! This means that lenses where the aperture stays about the same when you use the zoom are really the only ones where the use of the zoom in low light is practical. Ok, so which cameras have these exceptionally fast lenses? Panasonic, Fuji and Canon are the only manufacturers that make cameras with lenses that stay fast when you use the zoom - they only get 10 or 20 percent slower (f2.8 to 3.1) even when you use 10x or 12x zoom!!! (Compare this to the Minoltas, which get about 3 times (300%) slower, or the Casios, which get five and a half times slower (556%) when you zoom just 3x!!! Terrible!). Panasonic and Canon have image stabilization to boot, and the Fuji S5200/S5600 also has that great high-ISO mode. So if you want zoom 10 or 12X and you want to be able to do it indoors, then the Panasonics (FZ4, FZ5, FZ10, FZ20), the Canons (S1-IS, S2-IS), and the Fujis (S5000, S5100, S5200, S5600) are the ones that can stay at f3.1 or better. If you only want to zoom 5X, though, then Sony has the F707, F717 and F828, which can stay at an amazing f2.2 all the way through the zoom range! This means it can use shutter speeds over one and a half times as fast as the Canon, Fuji, or Panasonic when in low light!!! (But it can only zoom in 5X, not 10 or 12). So that's it for the zooming, which is important for sports and plays and concerts and so on. But what if you just want to take pictures at parties, or of the interiors of buildings, where using the zoom is not as important but you want to have an even faster lens? Well, those Sonys can do f2.0 without the zoom! The only camera with a faster lens is the Olympus 5050 (has f1.8). The Canon G6 also has an f2.0 lens. The Olympus C8080 has an f2.4 lens, which is still quite a bit faster than the usual f2.8. And to finish our list of faster-than-usual lenses, the Nikon 8400 has an f2.6 lens (which is just a tad faster than the f2.8 lenses found on just about every digital camera). So, for bigger-than-usual apertures, the best cameras are (Starting with the best): The Olympus 5050, the Sony F707/717/828, the Canon G6, the Olympus C8080, and the Nikon 8400. If you want to zoom in more and still be able to have extra-fast apertures, the Sony F707/717/828 is the camera for you. If 5X is not enough zoom, then the Panasonic FZs, the Canon S1 and S2, and the Fuji S5200/S5600, are the ones to go with for fast lenses. However, let me remind you once again that SLR lenses can be even faster.

And what about image stabilization? Most big zoom cameras have it, but few pocket-sized ones do. As I've said, the Panasonic FZ series and the Canon S1 and S2 do, and they have fast lenses too. The minolta Z3/Z5/Z6, the Sony H1, the Kodak P850, the Nikon 8800, and the Canon Pro1 also have image stabilization, but their lenses are not very fast (aperture slower than f3.1). The pocket-sized ones that have stabilization are the Panasonic FX7, FX8, and FX9, the Sony T9, and the Minolta X1. Then, the Panasonic LZ1 and LZ2 are "medium-sized" and have stabilization. And remember, of all of these, the Sony T9 is the only one to have a super-low-grain sensor, which makes this new Sony THE pocket-sized camera to have in low-light situations. Ah, yes, and there are plenty of SLR lenses out there with stabilization, from wide-angle lenses (Canon has a 17-85mm with IS) to big zooms (like 400mm, which is equivalent to 600mm on a digital SLR), but those usually cost a FORTUNE (no less than $500, usually more like $1500-2500, or $3000-7000 for the fast primes).

(If you want to buy any of those cameras, please visit Page 2 of this site and use the "[Price] at Amazon.com" links to buyt them at Amazon. You'll get a great deal, and you'll be helping to support this site! Thanks! =] )

So the cameras from the above lists should help you get better low-light shots, as should the tips I list in the paragraphs before that. It's tricky, and it will take a few tries. Slow shutterspeeds take some getting used to. But if you know what your camera is doing and what you can do to fix it (which is what I have just explained), then you should be able to figure it out. Good luck!

Throughout this site, I keep making a big deal about how the number of megapixels is not the sole indicator of the quality of the images produced by a camera, and how huge megapixel numbers may mean only a slight increase in image quality. I do this because camera companies have successfully convinced people that people should pay exorbitant amounts of money for cameras with 5, 8, or even 10 megapixels, implying that these produce images that are VASTLY superior to those of 2-, 3-, and 4-megapixel cameras. This is just not true. Sure, higher-resolution pictures might sometimes be better (or they may NOT be better, sometimes), but if they are better, the improvement really is marginal. I find it so sad that people do not realize this, which is the reason I make such a big deal about it.

The number of megapixels makes a smaller difference in image quality than do the grainyness of the sensor or the sharpness of the lens, which are basically determined by the size of the camera. Things like the autofocus speed and shutter lag will also have a much bigger impact on your picture-taking experience than whether your camera's sensor has 10 million pixels or 4 million pixels.

Basically, how grainy/smooth the sensor is, and how fuzzy/sharp the lens is, will affect image quality more than the resolution. This is a VERY important point. Cameras with more megapixels can actually take LOWER-QUALITY pictures if their sensors are grainy and/or if their lenses are not very sharp. Bigger lenses are usually sharper, and bigger sensors are usually less grainy.

(This means that, for example, a six-megapixel compact camera will take less-detailed pictures than a six-megapixel medium-sized camera, which will in turn take less-detailed pictures than a six-megapixel big-lens big-zoom camera, which will in turn take less-detailed pictures than a six-megapixel SLR. This also means that a three- or four-megapixel big-lens camera will take sharper pictures than a five- or six-megapixel pocket-size camera. So size matters, even more than resolution, when it comes to image quality).

However, even given two cameras of the same size, the one with higher resolution may still take blurrier or grainier pictures. But we'll get to that in a moment. First, let's talk about why size matters.

Here's my favorite demonstration of how sensor size has a MUCH bigger impact on image quality than does the number of megapixels: The first picture below was taken three and a half years ago, with an old 2 megapixel big-lens Fuji that I don't even have anymore. (This was back when I used to do aerodynamics research at Stanford. You can tell by the wires and power supplies hanging all over (and through!) the wind tunnel that the electrical-engineering aspect of this work was not my specialty). The second picture (the vertical one) was taken very recently, with my mom's new high-resolution pocket-sized Casio. I hope you can see that I am about the same "size" on both pictures:

Now here are crops of these images to show just my face. Which one is grainier? Which one is sharper? Which one shows more detail?

As you can see, the super-compact Casio's image is quite a bit grainier, to the point where you can't see much of the details of my face (such as, say, the bumps and curves of my ears, or the whites of my eyes, which are much easier to make out on the older picture - well, I guess I did kinda close my eyes a bit on the second picture, but still, you can see the difference). This means a four-year-old big-lens Fuji with TWO MEGAPIXEL resolution takes sharper pictures (images with less grain) than a brand new pocket-sized Casio. I hope this demonstrates that the size of the sensor (which you can guess just from the size of the camera) has a MUCH bigger impact on image quality than how many megapixels the camera has or how new it is. And I even locked the ISO on my mom's Casio to the minimum setting (50) to keep grainyness down!

Besides, even if this grainyness thing were not a problem, the number of pixels refers to the area of the image, while true angular resolution should be measured linearly. So if you go from 3 megapixels to 6, even assuming the lens is super-sharp and the sensor not-at-all grainy, then the increase in detail is not two-fold, but square-root-of-two-fold (about 1.4). If you go from 3 megapixels to 8 megapixels, the increase in linear resolution is only about 63 percent (1.63 squared is 8 over 3). So even if lenses were super-sharp and sensors not grainy, a huge number of megapixels really does not mean much higher quality.

Many people who go buy a digital camera start out just by saying "I want something with at least 5 megapixels", not realizing that the same camera but with a 3-megapixel sensor (i.e. the model that's one or two years older) would cost half as much but only have 22.5% lower linear resolution. And even worse, a lens made to project an image that is only sharp enough to make use of a 3 megapixel sensor will not project any sharper an image for the five-megapixel sensor, so a higher-resolution camera may take fuzzier-looking pictures when you blow them up. And even worse, a 5-megapixel sensor must have smaller pixel cells than a 3-megapixel sensor, so the smaller and more crammed cells produce grainier images. So, unless the lens is improved to actually meet the higher-reslution demands of a higher-megapixel sensor, and unless that sensor is built much more carefully in order to overcome the natural tendency for increased grainyness in smaller pixel cells, then the 5-megapixel image won't be any sharper than the 3-megapixel one.

Lenses are actually evolving in order to be able to project sharper images onto those tiny sensors. (That is to say, extremely expensive and precise manufacturing techniques that were once exclusive to the making of SLR lenses are now being used to make these smaller digicam lenses). But the problem of grain is not being solved, as you can see in the photo-comparison above. Most of today's 5-to-10 megapixel cameras produce VERY grainy pictures indeed, to the point where almost no improvements can be seen over 2-to-4 megapixel cameras, especially at higher ISO settings. Camera companies have managed to convince customers that "more megapixels" means "sharper images", despite serious problems with how grainy these higher- megapixel sensors are. Photography experts, who inspect these images closely(as you can do above) think that this is a real shame: People are buying immensely expensive cameras thinking that a six-hundred-dollar ten-megapixel camera takes MUCH better pictures than a two-hundred-dollar four-megapixel camera, not knowing that the tremendous increase in grainyness makes the improvement in image quality even more marginal. It really is a shame.

So, if you do want sharp pictures, get a big camera (which will have a big lens and a big sensor). If you get a smaller camera, don't worry too much about the megapixels: Get a 3, 4, maybe 5 MP camera, and use the money you save (from NOT having bought a higher-resolution camera) to buy a camera with a bigger screen, image stabilization, more zoom, a bigger lens, manual controls, or a more compact overall size (in other words, spend your money on features that make your picture-taking BETTER rather than wasting your money on megapixels).

A high MegaPixel count comes in handy when you want to crop pictures, and when you want to make enlargements. For uncropped 4x6 prints, 2 megapixels are usually enough, but for 5x7s and 8x6s, you kinda need to go up to 3 if you want a sharp picture. If your picture will be looked at from a small distance, I’d suggest a 4MP minimum for pictures that will be enlarged to 8x10. Then again, if your picture will NOT be inspected closely (say it is on a wall behind a couch, so no one will get closer to it than a meter or so away), then 8x6s of 2MP images, or even 8x10s if your 2MP camera has a really sharp lens, should be all right, and 8x10s of 3MP images are also definitely all right if no one comes to within 3 feet or so of them. I have a ton of 8x6s on my wall behind my bed. Most are 2MP, a couple are 4MP, and one is a really sharp 1MP (as far as 1MP images go).

Unless you're making posters, you don't need more than 3 megapixels, maybe 4. Two-megapixel images make fine 8x6s, and don't let the folks at the store tell you otherwise. I don't think anyone needs pictures with more than 3 or 4 megapixels, unless you're making calendars, having stuff printed on magazines, or trying to sell your photographs. (Pictures taken by 4-megapixel SLRs are used professionally, actually, like on calendars and ads, though, so you REALLY don't need more than 4). This is especially true of pictures taken with cameras that have big lenses. Cameras with big lenses and 3-megapixel resolution can take pictures every bit as nice as those taken by a smaller camera with 6 or 7 megapixels. Remember, the size of the camera influences image quality more than the megapixels, since a bigger camera is more likely to have a sensor that is not as grainy, as well as a sharper lens too.

But even when it comes to big cameras with big lenses(or when it comes to any two cameras that are the same size), a higher resolution does not mean better image quality.

I'll prove it to you: Jeff Keller, of the Digital Camera Resource Page (dcresource.com), once took two pictures of his house, one with the Panasonic FZ3 and one with the Minolta Z3, as part of the standard shots he takes with every camera for the purposes of comparison and evaluation. Both are large-sized ultra-zoom cameras with huge and quite fast lenses and equivalent focal lengths that go up to around 400mm. The Panasonic FZ3 has 3 megapixels, the Minolta Z3 has (despite what its name may suggest) 4 megapixels. The shot of his house taken with the 3-megapixel Panasonic can be found at http://www.dcresource.com/reviews/panasonic/dmc_fz3-review/houseshot.jpg , and the shot taken with the 4-megapixel Minolta can be found at http://www.dcresource.com/reviews/minolta/dimage_z3-review/houseshot.jpg , and you can see links to (and crops from) these shots here. The shots both look about the same, but if you blow them up and look at, say, a section of wall over his window, you see this:

Quite a difference, isn't it. What's surprising is that the first shot, the nicer one, was taken with the three-megapixel camera, and the second shot, the blurrier one, was taken with the four-megapixel camera. Both were large cameras with big zoom lenses. The Minolta's fuzzier lens and grainier sensor failed to capture the texture of the wall the way the Panasonic could.

One more comparison shot for ya, my last attempt to show you that megapixels aren't everything. I'll even use two Panasonic cameras, in case you want to accuse me of being biased towards Panasonic. I'll excerpt again from Jeff Keller's reviews, of the aforementioned FZ3, a three-megapixel big-lens camera, and the LX1, an eight-megapixel compact. People drool and/or get all wide-eyed at that number. "Eight megapixels! Wow!". Well, my point is to show that an 8-megapixel image can be not-too-different from a three-megapixel one, so just the fact that a camera has eight megapixels does not mean it can take pictures that are sharper than an older, cheaper, much-lower-megapixel camera.

Jeff took two pictures from approximately the same spot, again for evaluation and comparison purposes. The FZ3 picture (3 megapixels) is at http://www.dcresource.com/reviews/panasonic/dmc_fz3-review/P1020004.JPG and is from this gallery. The LX1 picture (8 megapixels) is at http://www.dcresource.com/reviews/panasonic/dmc_lx1-review/P1010002.JPG and is from this gallery. Below, I show excerpts of the same area from these comparison shots. First fom the 3 megapixel, then the 8:

Notice that, while the area taken from the 8 megapixel image is bigger (of course, since it has loads more pixels), it does not exhibit much additional detail.

I hope these pictures keep you from blowing a fortune on a super-high-resolution camera. THIS IS A VERY IMPORTANT POINT (which is why I repeated all this): Don't buy more megapixels than you need, and don't let the camera companies' marketing departments tell you how much you'll need. Three or four megapixels is all you need, even for 8x12s and for some cropping if you're gonna get 4x6s. Sure, 5-to-8-megapixel images MIGHT be a bit sharper, but probably they won't capture any more detail. Besides, unless you print them out huge, or crop a lot, you never even really get to see the additional detail (if there's any). And if your camera is a tiny pocket-sized 8MP compact camera, then your pictures won't look any better than if you had a larger (and much cheaper) 3MP camera.

And if you have any questions, suggestions, corrections, comments, criticism, if you just want to say hi, or if you need help choosing or using a camera, then please please please email me! (What other website promises free, attentive, personalized camera/photography email advice?)

And please, do tell your friends about my site!!!

Thanks for visiting. Come again!

Bernardo