Complete Digital Photography compared the Canon EOS 30D and Nikon D200 cameras. The conclusion is…Both Canon and Nikon offer excellent lower-priced alternatives to these cameras. The Canon Rebel and Rebel XT, and the Nikon D50 and D70s are all great cameras with good features sets and excellent image quality. However, they are all hampered by slower performance, mostly in the form of slower burst rates and slightly slower recycle times. Some of them also lack some of the features of the mid-range models. If you have found that the entry level SLRs don’t pack the features that you need, then the 30D and D200 are probably more in line with what you’re looking for.

“First the good news: both of these cameras deliver excellent images, whether you choose to shoot raw or JPEG. Yes, if you search through hundreds of images, you will definitely find some instances where the 30D performed slightly better than the D200. But right next to these, you’ll most likely find a set of instances where the D200 performed slightly better than the 30D. In both cases, you’ll probably find that any differences are easily corrected using simple adjustments.

With that said, it is worth noting that the 30D performs a little better at high ISO than the D200, particularly when shooting in low light, with long exposures. Both cameras provide built-in long-exposure noise reduction capabilities, but the D200 is noticeably noisier at ISO 800 and 1600, especially in very dark situations. What’s more, the noise manifests as both chrominance and luminance noise, meaning you’re gonna have your work cut out for you if you want to try to remove it. Note that the noise is not terrible, it’s just worse than what you find from the 30D. If you don’t do a lot of low-light shooting, then this will rarely - if ever - be a concern.”

Website: Should you buy a Canon EOS 30D or Nikon D200?