Macro shots on Canon 30D vs Rebel XTi

I repeatedly heard from different sources that shooting Macro on a Rebel XTi has its advantages because of the smaller sensor on the camera. 

Honestly I don't know much about sensors so I decided to take similar shots and let the results judge.

What I expected to see:

• I thought that the sensor difference will result in more cropping (less image area) in the XTi than the 30D.
  
• Better quality in the XTi due to its 10 mega pixels, compared to 8 mega pixels in the 30D.

What I actually saw:

• No cropping; same image size.
  
• Better quality in the 30D despite the mega pixel difference.

The Experiment

Two shots taken with the 2 cameras, using a tripod and a Tamron 90mm 2.8 macro lens.

I used the maximum length on the Tamron lens, same exposure setting, 2.8 aperture, and 1/4 shutter speed.

Myth # 1 busted: As you can see, there is no visible cropping, the area covered is practically the same.:

In this comparison of their levels curves, you can see how the 30D has a "richer" set of levels, whereas the XTi has a more limited one. This results are noticeable in the next shot.

Myth # 2 busted: Here, I zoomed at 400x in Photoshop and notice how the XTi shot looks a little "burned" and the 30D's colors look a little bit warmer (capture of light working better?):

(Click on the image to see it in large size)

Verdict:

Unless you zoom to 400%, you won't notice the differences, and you will be able to compensate any issues with good ol' Photoshop.

So the verdict is: I still like my Rebel XTi for its compact size and its comparable quality to the "xxD" family. :-)