Wednesday, February 06, 2008

Which DSLR? Well, it depends ...

When I first decided to get a digital SLR, there were a few things that were important to me:
  • How similar would my digital SLR be to my film SLR?
  • Could I use any of my film lenses?
  • Would I be able to shoot in low-light environments without flash?
  • Could I hang gallery quality enlargements on the walls of my home?
My film lenses were a variety of FD mounts – unusable with Canon’s Rebel line, so I was pretty sure they’d still be unusable with Canon’s digital SLRs. Not being tied to an existing investment in lenses gave me the ability to consider Nikon as well as Canon.

A couple of my friends had the Canon EOS 10D and the Canon EOS 20D, so I knew the pluses and minuses of these digital SLRs. I initially chose the Canon EOS 20D but opted for its replacement the Canon EOS 30D that performs better in low light environment and had a few new features I liked. I also liked Canon’s upgrade path from a camera body with a smaller sensor to one with a full-frame sensor – the Canon EOS 30D to the Canon EOS 5D to the Canon 1D Mark III. Last year Nikon didn’t have offer a camera body with a full-frame sensor so there wasn’t an upgrade path.

NOTE: If I were considering my first digital SLR purchase today (and not last year), I would probably buy a Nikon. The Canon EOS 40D isn’t a substantial improvement over the Canon EOS 30D (the body it was intended to replace) and in low-light performs slightly worse. Additionally Canon faltered on its successor to the Canon ID Mark III the Canon 1Ds Mark III.

What size enlargements do you plan to print?
Your end goals determine how many megapixels you need. If you’re only going to send photos via email and post online, you don’t need an SLR and you’re not going to need 8+ megapixels. Now if you want to produce gallery quality prints 20x30 or larger, then megapixels and sensor size becomes important. The relationship between pixel density and sensor size influences the amount of noise (think of grain in film images) and dynamic range (amount of detail in shadows) you’ll see in your images. The general rule is that given a fixed number of pixels, say 8MP, the larger sensor with larger pixels has a better 'signal-to-noise ratio,' resulting in less noise and smoother tonal transitions. For more information, check out the “DSLR Sensor Size and Pixel Density” article at http://www.sphoto.com/techinfo/dslrsensors/dslrsensors.htm.

Do you want to shoot in low-light environments without flash?
In low-light environments pixel density and sensor size is important as is camera sensitivity. Camera sensitivity is equivalent to ISO in film. Last week CNet posted a poll on “Megapixels versus Camera Sensitivity” (http://www.news.com/8301-13580_3-9858266-39.html?tag=tb) – given the same sensor size, readers overwhelming - over 90% as of today - chose sensitivity (10 megapixels and ISO 3,200) over more megapixels (12 megapixels and ISO 1,600). I’m regularly shooting in low-light environments where the use of flash is prohibited, which means the higher the ISO the better as long as I’m not trading off more megapixels on a small sensor. I’m willing to forgo tighter cropping as I’ll crop when I shoot by changing lenses or vantage point.

Full-frame sensor or smaller sensor?
From http://www.news.com/Nikon-answers-Canon-with-full-frame-SLR/2100-1041_3-6204252.html: “Full-frame sensors mean camera lenses behave optically as they do on film SLRs and that sensor pixels can be made larger and more sensitive. Smaller sensors ‘see’ a narrower field of view than full-frame sensors, so what a photographer sees through the viewfinder is different. For example, a lens with a 75mm focal length on a Nikon full-frame FX camera has the same field of view as a 50mm lens on Nikon DX. That ‘field of view crop factor’ of 1.5 for Nikon and 1.6 for non-full-frame Canon SLRs with the ‘APS-C’ sensor means that film photographers moving to digital SLRs often had to buy new wide-angle lenses.”

NOTE: The sensor in Olympus and Panasonic camera bodies is slightly smaller than those offered by Nikon and Canon.

There are currently only two manufacturers that offer full-frame sensors – Canon and Nikon (http://www.news.com/Nikon-answers-Canon-with-full-frame-SLR/2100-1041_3-6204252.html). Sony has announced a model that may be available by the end of 2008 (http://asia.cnet.com/reviews/digitalcameras/0,39001469,62037291,00.htm). Today, if you want a camera body with a full-frame sensor, you’re going to be choosing either Canon or Nikon. Previously purchased lenses and cost will determine whether you go with Canon or Nikon. If you want a full-frame sensor camera body (lens not included) for under $3,000, take a look at the Canon EOS 5D.

Previously purchased lenses?
If you’ve already invested in lenses, you’re probably going to want a camera body that can leverage that investment.
  • If you have Nikon lenses, you’ll get a Nikon.
  • If you have Canon lenses, you’ll probably get a Canon. I say probably, because if you have lenses developed for Canon’s APS-C sensor, the EF-S line, you won’t be able to use them with Canon’s full-frame camera bodies. This means you’ll be purchasing new lenses. (I knew I was going to be eventually purchasing a full-frame SLR, so I opted to use EF lenses and deal with the 1.6 magnification factor.)
  • If you have Konica-Minolta lenses, you may get a Sony. Sony acquired Konica-Minolta so these lenses may be compatible (http://www.dyxum.com/lenses/index.asp).
There are some camera bodies, for example, Olympus and Panasonic, which offer more flexibility, as they all use the Four Thirds system. The advantage for consumers who have Four Thirds camera bodies is that lenses from other manufacturers and third-party companies such as Sigma will work on any of the bodies.

Before you purchase, research! And try if possible!
Check out the reviews of different camera bodies, lenses, and filters before you whip out your credit card. Each model excels in certain situations and performs poorly in others; make sure you get equipment suited to your shooting environment. When you read a review, look at the equipment the reviewer uses for their photography and examine their portfolio to see if they shoot in environments similar to those in which you plan to work. Know the reviewer’s bias – my bias is towards Canon (I’ve been shooting with Canon since I was 15).

Here are some sites with a wealth of information:
The best research is your own field test. There are many options for renting camera bodies and lenses. In the San Francisco Bay Area, BorrowLenses.com (http://www.borrowlenses.com/welcome) rents Canon and Nikon equipment with convenient pickup in San Mateo or San Jose or delivery by mail. Plan a weekend where you can take your kit out for a test drive. With hands on experience you’ll know if the kit is right for you.
at 2/06/2008 10:13:00 PM