Advice on choosing a digital camera

A friend recently asked me for some advice about buying a digital camera. Here's what I wrote her, with a few changes. This advice will become stale, because specific camera models are always changing, but I don't expect the basic classes of camera to change too quickly.

Some general advice

We've owned Olympus, Nikon and Canon digital cameras, from compact to SLR. Our current cameras are both Canon brand. You have to start by asking yourself a few basic questions: What kind of camera do you want? What kind of film camera are you most comfortable with?

Almost all new cameras will be able to print decent 8x10 prints —anything with at least 3 megapixels. You'll be able to transfer photos to a PC or Mac with a USB port, and many can now print directly to certain inkjet printers. Most cameras these days come with special rechargable battery packs. You can also take the memory cards to Walgreens and get 4x6 (a steal at $.29 each), 5x7 or 8x10 prints from their 1-hour photo printing system.

I particularly recommend not getting stuck too much on how many megapixels a camera has, if you don't plan to make prints larger than 8x10. Choose a camera with other features you like, such as size or flexibility in shooting modes.

Many digital cameras (but not SLRs) have "movie" modes, but I have yet to see one that produces movies of acceptable quality (24 or 30FPS at TV quality), and the built-in microphone is invariably terrible. Some cameras can't even change the exposure or zoom within a single movie, some are limited to anywhere from 30 seconds to a few minutes per movie, etc. Don't get rid of your camcorder yet.

Like film, digital cameras have an ISO speed rating. Unlike film cameras, you choose a different ISO rating for each shot, not just when loading a roll of film. As with film, a higher ISO rating enables quicker shutter speeds but adds noise (grain) to the image. SLR-style cameras typically go from ISO100 to ISO1600 or ISO3200, with images up to ISO800 showing fairly little noise. Non-SLR cameras generally have an upper range of ISO400, with images up to ISO200 showing fairly little noise.

Beyond what comes in the camera box, you may want to get

At least one additional memory card, depending how many photos you want to shoot while you're away from your computer. I have a 1GB card, which is enough to get me through 2 days except in the most interesting surroundings—about 600 photos for the settings I use. In Ingrid's camera with a lower resolution, the same card could store over 2000 photos. The number of photos a card can store depends on the camera settings (image size and quality). The types of memory cards seem to change every few years, so don't bet on being able to use the same cards in your next camera.
A spare rechargable battery, or in the case of cameras that take AA batteries, two sets of quality batteries and a charger. Depending on the camera, the amount of time the LCD display is on, and the use of the flash, a battery change might come every 100 shots or every 600 shots.
For convenience, you might consider a dedicated USB card reader. The camera can connect to the PC through USB, but this often drains the batteries fairly quickly and is not as fast as a dedicated card reader. This also means less messing with cables, since the reader can sit on your desk and be plugged in all the time---just remove the card from the camera and insert it into the reader.

Specific camera recommendations

Compact cameras

If you want a compact camera without a lot of features, I recommend the Canon SD series, which is similar to the Canon S410 that I just got for Ingrid. They weigh around 8oz with the battery (the S410 weighs a little more) and are about the size of a deck of cards. The charger is about the same size, but much lighter. The zoom range varies for the different SD models, but on the S410 it's equivalent to 36mm to 100mm

(3x) on a traditional 35mm film camera. Update, 2006/2/10: For Christmas, I gave an SD400 as a gift. I haven't seen any prints from it, but onscreen the pictures are detailed and colorful.

Flexible non-SLRs

If you want a non-SLR camera with a bigger zoom range, I recommend the Canon S1 or S2. The S1 has a 10x zoom range (38mm-380mm equivalent), and the S2 has a 12x zoom range (36mm-432mm equivalent). These two cameras have an image stabalizer, for stable shots at lower shutter speeds and greater zoom. There's a lot more control over the photograph, including manual choice of F-stop, exposure time and focus, through the buttons on the camera. Manual focus in this manner is a very frustrating experience, though, compared to an SLR with a front focus ring. These cameras use "AA" batteries, with the use of NiMH-type rechargables recommended. A friend of mine owns a Canon S1.

SLRs

If you want a true SLR camera, then you have a lot of good choices, but you'll spend hundreds on the camera body alone. Canon's Digital Rebel (300D) is the one I own. I've probably spent around $1600 for the camera body plus 3 lenses (18-50mm, 55-200mm, 75-300mm IS). The current Canon models (Digital Rebel XT (350D) and 20D) both seem to be good cameras, and you can still find the previous-generation 300D and 10D at stores too.

Nikon also has some good SLR offerings, the D50, D70 and D70s. I know less about them. However, people are angry at Nikon right now, and for good reason. They reportedly encrypt the photos their cameras take when they are in the highest quality mode, and won't promise not to sue software developers using the US law called the DMCA just for writing software that can work with the files from Nikon's cameras.

With these digtial SLRs you can use any lens that would work with their current film SLR cameras, but the size of the sensor inside the camera is smaller a than 35mm film by about a factor of 1.6. This is called the "crop factor". So a lens marked "18-50mm" will give you a field of view equivalent to about 30mm to 85mm on a 35mm negative.

Samples and Reviews

Photos that Ingrid took with the S410 during her trip to Honduras are here:
http://greenthing.unpythonic.net/index.cgi/costarica

Some photos my friend has taken with his S1 are here:
http://www.abstract.a3.photoshare.co.nz/
He resizes all the images before putting them on the website. The actual photos are more detailed than this.

Some photos I've taken with the Digital Rebel are here:
http://photos.unpy.net/187339/