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The Two Classes of Digital Cameras
2006 KenRockwell.com
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INTRODUCTION  definitions   comparisons   summary

There are two completely different kinds of digital cameras: fixed lens and SLR (Single-Lens Reflex). Many fixed lens cameras attempt to parade as SLRs, which they're not. I'll refer to the fixed lens cameras also as point-and-shoot or p/s, and SLRs as DSLRs and SLRs.

Even the best fixed lens cameras are still way too slow to be used efficiently to photograph moving subjects, like people. SLRs on the other hand work quickly, just like a film camera, and are great for subjects that move. A real SLR, like the inexpensive Nikon D50, can do a lot more a lot faster than any fixed-lens camera, even if the fixed-lens camera costs twice as much and has a longer zoom range.

Even the most expensive and exotic camera whose lens can't come off is going to be too slow and a pain to use for photographing people. Many expensive digital cameras are still just very complex point-and-shoot cameras that take way too long to do anything. The $1,000 Sony DSC-R1 is a perfect example of a slow fixed-lens camera. The $500 D50 runs circles around it. That's why I suggest tiny and cheap point and shoots like the Casios for your pocket, and ignore the bigger and more exotic fixed-lens cameras like that Sony.

I define P/S cameras, the slow ones, as any camera with a lens that cannot be removed, which includes cameras costing well over a thousand dollars with long-range zooms, image stabilization and accessory attachment lenses. The Leica Digilux 2, Sony DSC-R1 and Nikon 8800 are just P/S cameras for example.

True SLRs and DSLRs all have completely removable lenses and a reflex mirror through which one views a live optical image on a ground-glass screen through the taking lens. The "R" in SLR stands for the Reflex mirror, and no camera is an SLR unless it has a that reflex mirror. It flips out of the way when the photo is made so the light from the lens can illuminate the film or CCD instead of the finder, which is why the viewfinder goes black when the photo is made. Take the lens off any SLR and you'll see this mirror sitting at a 45 degree angle showing you the backside of the viewfinder screen. If you can't take off the lens and see the reflex mirror it's not an SLR camera, regardless of how much smoke a salesman blows about through-the-lens viewing. Likewise you never can see an image played back through the finder of an SLR since their finders always show the live optical image. If you can review a recorded image through the finder you don't have an SLR.

Many P/S cameras are deceptively misrepresented as SLRs even though they only have electronic viewfinders (EVF) viewed through a peephole. These phony SLRs are also called EVF or electronic viewfinder cameras. They are NOT SLRs, even though they look like SLRs and you are viewing through the taking lens. They are easy to pick out: if you see the image on any kind of electronic LCD you're dealing with a p/s camera that will probably be a pain to use for moving subjects. SLRs show live optical images on ground glass that goes black for an instant when you take the picture. The image in a real SLR never freezes or gets jumpy because it's live. Likewise you can look into the lens of a real SLR and you'll see directly out of the viewfinder just like looking through binoculars the wrong way. The screens of EVF cameras are slightly time delayed and, especially in dim light, may make motion look jerky.

DSLR and SLR mean the same thing. DSLR is just an SLR that's also digital.

All of the fixed lens cameras, which include the EVF cameras, regardless of cost, are too slow and take too darn long to do anything. This is today's limit of technology. It's not you or your particular camera, they all stink for things that move fast. Sadly, commercial websites choose to ignore this in the interest of selling more cameras. On the other hand, true SLRs with interchangeable lenses work immediately with no waiting, just like your film camera.

The class structure didn't matter until 2004 when the prices and resolutions of the two classes crossed over. Because of this I consider any brand new expensive ($1,000) p/s camera obsolete since the new DSLR cameras are better for the same price. That's right, I'd pass on every single one of the new 8 megapixel p/s cameras that were announced in spring 2004 like the Canon Pro-1, Nikon 8700, Olympus 8080, Sony DSC-F828 and etc. since the DSLRs you can get now, like the Digital Rebel and Nikon D70 are so much better for the same price. As of 2005 you can get a Nikon D50 for less than the Sony DSC-R1. Yes, the $1,850 Leica Digilux-2 is also underwhelming and I'd skip it too. Of course the makers of new expensive p/s cameras are promoting them heavily and all the commercial websites of course are pushing them too, thus the confusion.

To make a long article simple, today's 8MP and 10 MP and other fixed lens digital cameras have electronic viewfinders that look like crummy 15 year old TVs, work so slowly they can't focus on anything unless it's holding still and generally can be frustrating unless your subjects are still. By comparison the interchangeable lens true DSLRs have great optical viewfinders and immediate operation, just like film. The DSLRs also make much cleaner images than the P/S cameras. The only reason I see for getting an expensive P/S is smaller size. Unlike film P/S cameras, the digital ones are frustrating to use. Actually if you do want a tiny P/S I'd get a Casio credit-card camera. I bought the EX-Z750.

It's important to understand these classes so you can make the best choice. If I get too technical just skip to the summary after you read the definitions.

Commercial websites and magazines forget these differences and spend all their time comparing cameras within the same class. Within a class the cameras are pretty similar. The differences between classes is huge. Some of these camera-company sponsored websites even show example photos showing p/s cameras having similar quality to DSLRs. Sure, under controlled conditions where the p/s has enough time to turn on and focus and shoot at a primitive ISO 50 or 100 it will look the same as a DSLR at ISO 400, but so what? In real world use with moving subjects it becomes much more difficult to get those results from p/s cameras since they work so much more slowly and have slower ISO speeds. Thus in the real world with a p/s one either misses the shot entirely, gets the wrong timing giving a bad composition, or gets more grain when the ISO is set to the same value as a DSLR. Colors are the same.

Today some people are misled by the meaningless 8 or 10 Megapixel banner specs of some p/s cameras that try to imply better image quality than the true DSLRs, and some of the p/s are styled to mimic DSLRs to impress the innocent. What's up?

(There is a third class of professional digital backs for studio cameras and of course the cameras NASA flies to Mars. Since they all cost $20,000 or more and are all painful or impossible to use out in the field I'll ignore them since you and I can get better results for less money and less effort with larger formats of film.)

DEFINITIONS back to top

Point and Shoots (p/s)

Minolta X20
  Canon A75   Nikon Coolpix 8700
 

A point-and-shoot is a digital camera that has its lens permanently attached and has continuous viewing through the CCD via the LCD screen. This includes cameras that have accessory lenses that attach to the front of their fixed lenses. They have small image sensors (usually CCDs) less than an inch across and usually look like the cute little point-and-shoots they are. They range from $29 credit card cameras through nice, normal $300, 3MP 3x zoom Canon A75 to the $1,000 8 MP, 8x zoom cameras like the Sony DSC-F828, Nikon 8700, Minolta Dimage A2, Olympus C-8080 and Canon Pro-1 and the $1,850 Leica Digilux 2.

Some p/s cameras like this one here even claim to be SLRs and are not. See the definition of a real digital SLR below. Actually that Panasonic Lumix DMC-FZ10 is a very slick camera, just don't confuse it with a true DSLR.

It doesn't matter if it has a no-name lens or a sticker from Carl Zeiss or Leica; the image quality is pretty much the same around any given price point. There is little real difference even between the top of the range and the middle, although of course people trying to sell you an expensive camera, or people who want to justify a recent purchase, will try to get you to think so.

Most p/s digitals are designed by the same people who design VCRs and try to make them as complex and overburdened with needless features as many other electronic gadgets bought by gadget hobbyists.

An exception for image quality is 2005's Sony DSC-R1. It has the same sized sensor as a true DLSR, thus it's image quality is as good. Focus speed and flexibility are the same as other P/S, but for static subjects it is an excellent, if expensive, choice.

DIGITAL SINGLE LENS REFLEXES (DSLRs)

Canon Digital Rebel
  Nikon D100   Nikon D2H
 

SLR stands for single lens reflex. (This is a twin lens reflex, which does not exist in digital.) True digital SLRs have interchangeable lenses, reflex mirrors (thus the "R" in DSLR), direct ground glass viewing and much larger image sensors.

The reflex mirror reflects the light from the lens to a ground glass viewing screen on which you focus and compose. You are looking at the actual light coming through the lens as reflected from the mirror, thus the phrase "reflex." When you make the photo the mirror flips out of the way to allow the shutter to expose the CCD. Because of this the LCD cannot show the image while composing, you view on the ground glass. Also because of this you cannot make movies with DSLRs, since the mirror is usually in the way so you can compose.

This class used to cost $20,000 in 1991 with Kodaks hacked out of Nikon bodies. They dropped to $5,000 in 1999 with the Nikon D1, and today the $999 Nikon D70 offers better performance than anything else mentioned above. Other DSLRs are the Canon Digital Rebel, 10D, 1DS, 1D-MkII, D30, D60, and 1D; the Nikon D1X, D1H, D100 and D70 and so forth.

DSLRs are usually designed by the people who design cameras, and therefore they usually have just the right set of necessary features to make great photos fast.

You can tell I have a slight bias. By all means you should have a $300 p/s in your pocket for snapshots, however in my opinion the $1,000 models are just gadgets for tinkerers, not for photography compared to the far better DSLRs in the same $1,000 price range.

COMPARISONS back to top

Point and Shoots (p/s)

P/S Strengths

Smaller size, less weight, almost silent. This is pretty obvious; the only noise they make is their teeny motors zooming the lens and their electronic leaf shutters. You have to remember to turn off the idiotic fake camera noises.

Very accurate ambient light metering. The camera already knows what the exposure should be because the image sensor is exposed to the image while you are composing.

Correct professional aspect ratio. Almost all p/s shoot in 4:3 (1.33:1) aspect ratio, the same shape as almost every TV and computer screen and closest to professional film and paper formats. You can fill an entire laptop or monitor screen or project the images with no loss or cropping. Even vertical compositions on a projector are far bigger than the skinnier images from a DSLR. When printing on standard sized paper you can use your entire image and all the pixels you paid for without having to chop off the sides to fit on an 8 x 10. The reason this shape is popular professionally is simply because the majority of horizontal and vertical subjects fit into it well with a minimum of cropping. Of course every shot is different, and this shape, taller than the skinnier shape of the DSLRs, makes the best overall use of image area.

Almost unlimited depth of field. Because the p/s have such teeny sensors they use very short focal length lenses, even if they mark an "equivalent" 35mm focal length on the outside of the camera. Their teeny lenses have huge depth of field, even wide open.

External LCD (sometimes). Some p/s have a monitor that can flip away from the camera at arbitrary angles. This allows you to make crazy images from odd angles above your head or around corners while still looking at the monitor. You couldn't do this if you had to jam your face against the back of the camera as with a DSLR. The LCD on a DSLR does not provide a live image while composing like the p/s.

Movies with sound. Most p/s cameras let you make annoying movie files complete with sound like this. Depending on the format they use you can post these on websites and email them to your friends. The most useful format is .MPG like my Sony Mavica made; other cameras may use clumsier files like .AVI which my Canon does, which then need to be converted to other formats like .MOV before most people can see them. Many p/s cameras today can shoot full resolution, full motion video in clips up to about 30 seconds, which can be edited together on any Apple computer made in the past few years to create feature length motion pictures for theatrical or network release. They can shoot for many minutes, limited only by your memory card, at the smaller resolutions. DSLRs can't make movies because of their reflex mirrors.

(Not a strength: long ratio zoom lenses). Yes, you easily can get digital p/s cameras with 6x, 8x and 10x zoom lenses, but likewise you can get 28-200mm and 28-300mm zooms for any DSLR. You also can get a screw-on or slip-on wide converters for the zoom to get wider than the non-so-wide 28mm end of these zooms for DSLRs.

P/S Weaknesses

Lower image quality due to smaller image sensors with tiny pixels. The sensors (also usually CCDs) are tiny compared to the real DSLRs. The p/s cameras have CCDs typically only one fifth as big along each side, or only one 25th of the area for the sensor as well as for each pixel at the same resolution. Because the p/s cameras use such tiny pixels they are subject to two serious flaws: 1.) much more noise (grain) and the related 2.) much slower ISO speeds.

Even the fanciest p/s cameras have sensors only 2/3" diagonally. Also as they add more pixels each pixel gets smaller, and therefore noisier.

The Sony DSC-R1 is the sole exception here. It has a sensor as large as a true DSLR.

There is more noise (grain) because the smaller pixels are much less sensitive to light. Each pixel on the p/s sensor chip is smaller than the pixels on a DSLR, so it collects fewer photons. Those photons do a dance and become electrons, which are then amplified to become your picture. Since the internal noise of the electronics remains the same the noise is much greater by comparison to a DSLR at the same ISO because the camera needs to amplify the signal much more.

Because of this the p/s cameras have to work at much slower ISOs to get a decent image. The p/s cameras typically default to ISO 50 and go up only to ISO 400, at which speed they look pretty bad. By comparison most DSLRs start at ISO 200 and go to ISO 1,600 to 6,400. Because you have to use slower ISOs in the p/s you wind up with blurrier photos compared to DSLRs because of the longer exposure times. Longer exposure times lead to blurring when either the subject or camera moves, which is most of the time unless you enjoy looking at photos of test charts. Remember due to the huge depth of field that you often can shoot a p/s wide open to get faster shutter speeds, and that's how their Program settings usually default.

Crippled ISO range. The noise (grain) problems of p/s digitals limit them to ISO 400, which usually looks pretty bad. Some push it as far as ISO 800. Due to the teeny sensors with teeny pixels you really want to stay at ISO 100 or below with your p/s for a clean image. By comparison, real DSLRs usually start at a minimum of ISO 200 and go to at least ISO 1,600 at which point they still look pretty good.

Slow operation. As anyone who has used one of these digital cameras know they take way too long to do anything. Even the new $1,000 8MP models and the $1,850 Leica Digilux 2 still take too long to do anything, and often lock up after every shot by design.

Their internal electronics just aren't fast enough as of 2004 to respond as fast as we'd like. Some cameras are much better than others, but overall these cameras are frustrating for photographing anything other than test charts.

You have to wait for them to turn on, and then you have to wait after you press the button for something to happen. Even zipping through the annoying menus takes time; time I don't have. With these long delays you have to hope your subject doesn't loose interest or fall asleep while you're trying to get a photo. You can't just leave them on all the time as you can with a DSLR because the batteries will run down

Most of them have some sort of rapid fire mode which you can ignore. Even if they can pound off 5 frames per second the only frame you care about is the first, and it takes them too long to crank off that first frame.

Bogus menus. Real cameras have buttons and knobs for making changes instantly. Most p/s use menus to change even the most basic settings required for every shot, like ISO and white balance. Menus are bogus because they require you to stop paying attention to your photography and redirect it to a screen where you have to play twenty questions to change anything. You can adjust most DSLRs without taking your eye away from the viewfinder. The biggest indicator of whether or not a camera is suitable for pro use is whether or not a camera requires any menus for the basic adjustments.

Slow viewfinder. unless you use the little peephole direct optical viewfinder the electronic viewfinder or LCD is actually delayed a fraction of a second. Just wave your hand back and forth in front of it if you think I'm kidding. Because of this you cannot use the LCD finder for photographing things that move, like people, because you'll miss the shot. This is just as bad for the expensive "EVF" electronic viewfinder cameras which make you look through a little peephole to see an even smaller LCD screen through a magnifier. Manufacturers love to lie about the EVF cameras: they claim that they are real time and you can plainly see for yourself with a moving hand that there is a delay in what you see. Even a fraction of a second is the difference between a prize winning photo and the delete button. That's why pro sports photographers love to have cameras that run at 8FPS or more because even an eighth of a second makes a completely different photo when shooting action.

Slow AF. These cameras have teeny little motors to pull focus and just don't focus very quickly. I've never found one that can track moving objects for a sequence of photos as the DSLRs can.

Idiotic motorized zoom lenses. Instead of just turning a zoom ring like a real camera you have to twiddle with a switch that runs a motor that turns the internal ring for you. These Rube Goldberg designs work way too slowly, and you rarely if ever can control the zoom speed. Even worse, some cameras can't be set to every possible zoom setting; many only have several steps between which the zoom lens can set itself, making exact framing impossible. The Sony DSC-F828 is unusual for p/s cameras since it has a real mechanical zoom ring.

No superwide lenses. The widest cameras only can zoom out to a mild wide angle. To get really wide requires silly external wide angle converters, most of which curve the straight lines. You have to look long and hard (try Nikon) for an expensive converter to give passable results.

Digital Single Lens Reflexes (DSLRs)

DSLR Strengths

Better image quality: larger image sensor = bigger, better, cleaner pixels. DSLRs have sensors almost as big as 35mm film, which is about five times the linear dimension or 25 times as much area as the sensors in p/s cameras. These huge pixels gulp in every last photon of light so even at high ISO settings the images are much cleaner than p/s cameras. This lets you use high ISOs all the time, with even better results than film in low light. This lets you stop action and stop blurring for sharper photos in many more situations than a p/s.

Instant operation: The DSLRs work like a real camera: you turn them on and they're on. You press the button and they take the picture, duh. This is unlike the p/s cameras where you have to sit around and wait while they turn on, and then press the button and hope your subject is still there whenever the camera decides to go off. You won't miss the shots you do with a p/s.

Power: You leave a DSLR's power switch ON all day, just like a film camera. The camera immediately wakes up any time you tap the shutter button and otherwise sleeps. The only thing that takes any power is the color LCD which turns off automatically after each shot. The camera is always ready to shoot. You only turn off a DSLR when you put it away to prevent accidental operation. Others may vary, and the Nikons I've used are all like this. There is no "sleep" mode since that's the only way the camera works. Battery life is about the same as the p/s camera class.

Fast autofocus. The DSLRs have the fast AF motors of their film cousins. They also can track subjects in motion for great sports shots.

Real-time ground glass viewing. Since they are real SLRs they have a mirror that flips down most of the time so you see directly through the lens on ground glass. Unlike the time delayed LCDs of p/s cameras you are seeing what's happening now so you can catch the action.

Huge range of lenses. You can use all the lenses you already own and can buy new and used. Even 15 year old autofocus and 40 year old manual focus lenses can be used, depending on your camera. You can get super-duper telephotos and fisheyes, even used.

Huge, fast ISO range: Even the cheapest DSLRs go to at least ISO 1,600, and many go to ISO 6,400 in push modes. Most DSLRs, unlike film, give great images at ISO 1,600. Many DSLRs have ISO 200 as their slowest ISO because there's no need for slower speeds to get great quality as we had to do with film. If you need to use wide apertures in daylight most DSLRs have very, very fast shutters to let you do this at ISO 200. For instance, the Nikon D1 / D1H / D1X have shutter speeds to 1/16,000 (!) and even the inexpensive D70 goes to 1/8,000.

Selectable depth of field. Since the DSLRs use regular lenses you get depth of field pretty similar to film. If you want a nice smooth portrait background just open up your lens. This contrasts to the p/s which usually have huge depth of field even wide open.

DSLR Weaknesses

Larger and heavier. DSLRs tend to be klunkier, although the latest inexpensive ones are as light and as small as the biggest p/s models at the same price.

Obsolete too-skinny aspect ratio. The DSLRs blindly copy the obsolete 3:2 (1.5:1) aspect ratio of 35mm film. The longer, skinnier 3:2 shape is a throwback to 1913 when an asthmatic hiker who couldn't carry a real camera developed a way to jam 35mm movie film into a still camera and chose an elongated format to allow a little more film area to be used with the tiny film. (See the history of the Leica camera to learn more.) Using a DSLR with its outdated 3:2 aspect ratio means every time you do a digital slide show you'll have black bands across the top and bottom of your screen, or even worse, have even bigger sidebars for verticals compared to the same images made with a p/s. That's right: if your main use for digital images is for computer presentation you get more resolution from a cheap p/s since you can fill your whole screen without cropping. Your screen has less than a megapixel; you ought to use all of them that you can. On the other hand, if you main distribution channel is a website then the longer ratio is fine, since the biggest safe area of a standard target browser screen is 700 x 400 pixels, or 1.75:1. This is all artistic preference of course, and it just turns out that most things most people photograph and paint fit better into a squarer shape than the long skinny one that 35mm film used to use. It makes better use of your limited resolution to have a squarer shape, since you less often need to throw away the sides of your image for printing on standard paper sizes or screens. Few subjects are as elongated as 1.5:1. The Olympus E-1 and its brothers in the 4:3 system fix this.

They're noisier. DSLRs have a lot of motors and mechanics which make the same noise as any other film camera for each shot. I always turn off the stupid imitation camera sounds in point-and-shoots.

No live LCD: You have a far better viewfinder with the ground glass of a DSLR. Some folks new to DSLRs don't realize that the LCD on the back does not show the image while you are composing as it does on p/s and video cameras. On a real DSLR the reflex mirror instead reflects the image to the ground glass for you and away from the CCD, which is only exposed when the photo is taken. You'll notice that your ground glass viewfinder goes black during the moment of exposure, since the mirror flips up and lets the CCD get exposed. As of 2006 some second-tier SLRs like Olympus have added live LCD viewing.

Dust. Here's the dirty little secret of DSLRs. Dust collects on the sensor and can become visible in every one of your shots. You won't see this through the viewfinder and you can see it on the LCD when you play back with magnification. P/s cameras are immune because their little optical systems are sealed. Some fringe DSLRs like the Olympus and Sigma have clever ways around this, but with Nikon and Canon you need to worry about dust and dirt when you change lenses and periodically clean the sensor. I've had my Nikon DSLR for over two years and only had to use a Shop-Vac to suck out the dust a few times.

Similarities

Resolution, which is the least important specification (as you can read here) is pretty much the same between the two classes. Even seemingly large differences, like 4MP to 6MP, are insignificant. Today's DSLRs range between 3 to 14MP with 6MP almost a standard, and the p/s range between 1 to 8MP. For the same MP rating the image quality is better for a DSLR as explained above under sensor sizes.

Battery life also is pretty similar between the two classes. The bigger DSLRs just have bigger batteries. DSLRs get a couple of hundred to a couple of thousand shots on a charge. Some of the earlier p/s cameras had awful battery life, but today most of the p/s also have OK battery life. The good DSLRs come with rechargeable batteries and p/s come both ways.

SUMMARY back to top

Yes, of course I'm opinionated and of course this page contains generalizations.

For a small snapshot camera get a $300 point-and-shoot. I have one, love it, and take it everywhere.

If you want to spend a grand for serious digital photography forget the expensive p/s cameras and go straight to any DSLR. Since you can get a far superior DSLR for what you used to have to pay for just a p/s as of 2004 I see no need for the expensive p/s digital cameras.

The reason we still have expensive p/s cameras today is because camera companies still have two sets of development and marketing teams, one for each class of camera, so there are still people at these companies pushing the expensive p/s cameras even though the DSLRs made by the same company are better for the same price. Other companies, like Sony, don't make any real DSLRs and of course they will promote their p/s cameras.

Don't waste $1,000 on a point and shoot unless you really want to trade off ease of use, speed and image quality for a little size and weight.

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