I bought the Rebel EOS Digital XTi 400D to upgrade my almost 3-year old Rebel EOS Digital 300D (which, by the way, is still a great camera). I won't go into the technical differences between the two cameras, but I will say this: the differences between the two cameras are worth the cost of the upgrade for me. Here's why.
Although too much can be made of additional pixels, the upgrade from 6 mega-pixels to 10.1 mega-pixels simply means that more data is available to process pictures. I shoot in RAW mode, so I'll take all the additional information I can get.
The larger LCD screen on the 400D is much, much, much better than that on the 300D. I really like a) the much larger view of each picture taken, and b) the clarity of the camera settings when displayed on the screen. I also really like the feature that automatically turns off the screen when the camera is raised to the eye for composition. I honestly didn't realize how tiny the 300D LCD is until comparing it to the 400D. Thank you, Canon, for the bigger screen!
I also like that the 400D comes with new, selectable Picture Styles (Standard, Portrait, Landscape, Neutral and Faithful) that automatically make small corrections to things like sharpness, contrast and color.
The camera start-up time on the 400D is also significantly quicker than that of the 300D. I once missed what I now think is the shot of a lifetime because I couldn't get the 300D to start up fast enough. I believe the 400D would have gotten the shot.
It's also much easier to select the type of Auto Focus mode on the 400D. When your camera is set to shoot in One Shot mode, but you find yourself in the middle of movement and action, the 400D makes it easy and fast to switch to AI Focus or AI Servo - essential for sports shots.
For those who have come to appreciate and rely on the histogram to determine proper exposure, you now have the choice between Brightness and RGB.
I also like the increased continuous shooting speed of almost 3 frames-per-second. A very nice feature when shooting the dog, kids playing or outdoor events.
Finally, for those who are concerned about dust on the sensor, the new automatica sensor cleaning capabiltiy is a very nice to have.
On the downside, the 400D camera grip is a bit too small for larger hands. It's manageable, but not as comfortable as the grip on the 300D. However, I mostly solved this problem by attaching an Opteka battery grip, which enlarged the grip surface.
Also, the smaller battery size on the 400D means that you can't interchange batteries between the 300D and the 400D. It also means that the (optional) battery grip that worked on the 300D does not fit on the 400D.
BOTTOM LINE
Am I happy that I upgraded from the 300D to the 400D? You bet. I'd do it again in a heart beat.
Would I recommend this camera to the serious amateur? Absolutely. It's worth every penny to someone getting his or her first Digital SLR or upgrading from the 300D.

Canon Digital Rebel XTi 10.1MP Digital SLR Camera (Black Body Only)
4.2
| 1,007 ratingsPrice:
Last update: 01-27-2025
About this item
Stores images on Compact Flash (CF) memory cards; powered by battery pack NB-2LH
DIGIC II Image Processor provides fast, accurate image processing; Picture Style settings for added creative control
Large 2.5-inch LCD display; body only (no lens included)
10.1-megapixel CCD captures enough detail for photo-quality 18 x 24-inch prints
New self-cleaning dust function, plus Dust Delete Data Detection in included software
10.1-megapixel CCD captures enough detail for photo-quality 18 x 24-inch prints
Large 2.5-inch LCD display; body only (no lens included)
New self-cleaning dust function, plus Dust Delete Data Detection in included software
DIGIC II Image Processor provides fast, accurate image processing; Picture Style settings for added creative control
Stores images on Compact Flash (CF) memory cards; powered by battery pack NB-2LH
DIGIC II Image Processor provides fast, accurate image processing; Picture Style settings for added creative control
Large 2.5-inch LCD display; body only (no lens included)
10.1-megapixel CCD captures enough detail for photo-quality 18 x 24-inch prints
New self-cleaning dust function, plus Dust Delete Data Detection in included software
10.1-megapixel CCD captures enough detail for photo-quality 18 x 24-inch prints
Large 2.5-inch LCD display; body only (no lens included)
New self-cleaning dust function, plus Dust Delete Data Detection in included software
DIGIC II Image Processor provides fast, accurate image processing; Picture Style settings for added creative control
Stores images on Compact Flash (CF) memory cards; powered by battery pack NB-2LH