I don’t claim to be a camera expert, but I’ve been reading a lot of reviews lately, and bought a digital SLR camera a couple months ago. It seems like these are really popular lately and everywhere I go in NYC I see people walking around with huge honking cameras swinging from their necks. It seems like every make/model has its own particular strengths and weaknesses, and so here’s some things I have noticed. Most of this stuff I learned from reading the long, insanely detailed reviews at http://www.dpreview.com/. The following is just my quick personal synopsis:

Canon: Canon seems to have the best image quality around, at least in terms of noise. They use CMOS sensors instead of CCDs– people debate about the relative merits of these a lot. Apparently the CMOS sensors are less noisy but don’t hold highlights and shadow details as well as CCDs. CCDs are more common. I’ve owned two Canon point-n-shoots and they were both excellent (an S50 and an S60.) I don’t know anything about their lenses. Canon’s Digital Rebel is a really popular model, but I looked at a lot of image samples online, and I wasn’t impressed with how it held details– I think if you’re going to go Canon, spend a few hundred extra for one of the nicer models. Also, Canon’s flagship camera, the 1D, seems to be the standard choice for professionals. Canon is the #1-selling brand in the US.

Nikon: Nikon seems to lead the pack in autofocus performance, at least on the high-end models. The D300 has a 51-point autofocus system (as opposed to the measly 11 points on my Pentax K10D and the 9 points on the Canon 30D.) Again, I don’t know anything about Nikon lenses. Nikon seems to be a popular choice with sports photographers who need to freeze fast-moving action. I believe that Nikon is the #2-selling brand in the US.

One nice thing about owning a Canon or a Nikon is that you can eventually invest in some really high-end lenses from companies like Voigtlander. The other brands, not so much. One not-so-nice thing about owning one of these cameras is that you cannot put older lenses on them; they keep changing the lens mounts every few years so that you have to upgrade. This basically locks you out from buying cheap used lenses on eBay.

Olympus: I looked at the eVolt 450 in the store– seems pretty nice. It’s very small and lightweight. I found the menu system to be confusing, though, and there were far too many buttons and dials on it. One thing you should know is that Olympus uses the “Three-Fourths System,” which produces images that are more square in shape than the other brands (and therefore, less like a film camera image.) For me, this was a turn-off, but Olympus claims that this somehow gives them an advantage in image quality. One pro of the Three-Fourths System is that you can use lenses from other manufacturers like Sony.

Sony: I wasn’t impressed by the image samples online; too grainy and soft. I don’t know anything in particular about their cameras.

FujiFilm: This is basically a Nikon body with Fuji electronics inside. They supposedly have the best tonal range, and are popular with wedding photographers, who need to make a bright white wedding dress and a deep black tuxedo both look good in the same shot. Back when I shot film, FujiFilm was my favorite brand of color film, and so I don’t doubt that they’re telling the truth about their image quality :) You can use Nikon accessories, including lenses, with these cameras.

Sigma: Their Foveon X3 sensor is totally different than any other camera’s. It looks better in strong light (sun and flash) but fares worse in low light. I believe their lens mount is compatible with Pentax (although I might be mistaken.)

Pentax/Samsung: Back in the 60′s, Pentax was bar-none the top name in SLR cameras, but today they are just a shadow of their former selves. They still make some of the best lenses around, and anything with “Limited” in the name is sure to be a winner (some of the cheaper lenses are real clunkers, though.) If you ever see one of their classic lenses from the 60′s– a “Super Takumar”– buy it immediately. They are some of the best lenses ever made, and you can get an adapter to put it on your Nikon or Canon. Also, any Pentax lens from the 70′s up to the present day will work on their latest cameras. The high-end Pentax camera are also weather sealed, which means you can take them out in the rain and not worry. I think you have to go several more steps up in price with Canon or Nikon to get that.

Samsung is in partnership with Pentax and makes cameras with nearly identical mechanical parts, but different electronics with fewer features– I’m not sure why you’d pick it over the Pentax. Samsung also manufactures the image sensors in Pentax’s latest camera.

OK, so that having been said I eventually bought a Pentax, mainly because it was cheap, but didn’t skimp on features. For me, the weather sealing was a major plus. (I killed my Canon S50 by getting it wet, and didn’t want to repeat the experience with a camera twice the price.)

I have mixed feelings about my K10D– it is very nice to use, with very intuitive controls. It was the only camera in the store that I felt like I could just pick up and start shooting with. Its main weakness is that it performs poorly in low light, and so I wouldn’t recommend it for anyone shooting in bars, music venues, etc. The in-camera stabilization is supposed to help you here, but the sensor is just too noisy to make a good image at ISO 1600. Image quality in daylight or with flash is very good, especially if you shoot in RAW mode (which I do.) JPEG quality is decent but not great. The camera holds detail very well.

People complain about the autofocus system, but I haven’t had any problems with it. I had a chance to play with my stepbrother’s Nikon D80 and I actually thought the AF was worse in low light than my Pentax (that’s one of Nikon’s lower-end models, though.) The camera definitely tends to underexpose by a little, but this hasn’t been a problem to correct on the computer.

Starting with the K20D, Pentax is switching to a CMOS sensor from CCD sensors, and supposedly this fixes their low-light issues, at least in terms of noise. I haven’t had a chance to try one yet. The AF and AE systems are the same as the older models.

I bought a Pentax 21mm Limited lens for about $450 and I love it. It’s made out of metal instead of plastic, and has a nice silky feel when you focus it. The sharpness and contrast are extremely crisp and clear. There’s some minor vignetting at f/3.5, but it’s gone at f/4. (That sort of thing is easy to fix with digital, anyway.) Also, the lens is only about 1.5″ long, which makes the camera easier to tuck into my backpack and carry around all the time. (I believe that Nikon also makes these skinny “pancake” lenses, but Cannon does not.)

All in all, I’m pretty happy with it, despite the problems I mentioned above. I will definitely check out Pentax again when I’m ready to upgrade. I’ll also look at Nikon, because I do a lot of street shooting, and I’m intrigued by the 51-point AF on the D300. Also, I definitely want another pancake lens if I switch brands.

Also, since I am apparently plugging Pentax here, here’s a sample image from my K10D :)

I hope this helps anybody who’s thinking of buying a new camera.