Canon 400D Versus Canon 450D

The Canon EOS 450D was digital camera introduced into market in January 2008. I'm sure there will be lots of people asking "Should I get a Canon 400D(XTi) or 450D(XSi)" or "Should I upgrade from my 400Dto a 450D"? Here is the comparison between Canon 400D and 450D which shows what’s new and what’s change of the 450D.
 1. The Camera Body
The 450D is noticeably lighter than the 400D, around 75g lighter. The Dimensions of 400D is 127 x 94 x 65mm( 5 x 3.7 x 2.6in), 450D: 129 x 98 x 62 mm (5.1 x 3.9 x 2.4 in).  Despite its smaller size, the grip on the 450D is reported to be much better built than the 400D models.
The 450D adds a rubber layer on the grip and on the thumb rest at the back of the camera. The larger grip is also a welcome change for any people. It feels more comfortable. The plastic used in 450D is similar to the ones on the Sony A100 and EOS 350D. Some people feel coarse and a little cheap, and they think the 400D plastic is slightly smoother, more glossy. The 450D takes out the neon green "Power" LED light. In its place is the new ISO Button. You press it once, then turn the main dial to adjust the ISO. Then half-press the shutter to set the ISO. You can now change the ISO setting on the fly, without taking your eyes off the viewfinder.
2. LCD
 The first thing you'll notice when you look at the back of the 450D is the large 3" LCD screen (400D 2.5in). It's great to look at and makes pixel-peeping much more fun to do. Avoid frustration from having to try to make out details on a small screen.
3. Live View
The 450D introduces an additional, contrast-detection Autofocus capability when you're shooting in Live View mode. Many people are excited with this new feature.
4. Viewfinder
An outstanding improvement is the bigger and brighter viewfinder (compared to the 400D). It really makes a lot of difference if you need to peer through the viewfinder at long periods of time just to capture that perfect image (such as in wildlife photography).
5. Sensor
The 450d has a 12 MP Sensor( 400D:10 Mp). Does 12 MP have benefits over 10 MP? In fact, it's not a big deal. The jump from 10MP to 12MP is smaller (+20%) than the jump from 8MP to 10MP was (+25%), so for the most part it won't be a significant difference.
6. ISO Performance
       The 450D JPEG turns out much nicer than 400D’s. The noise level of the 400D is notably higher than the noise level of the 450D at ISO 1600 even when viewed fit-to-screen. The difference between the amount of noise (grain) just becomes more obvious when the images are viewed at 100%. Clearly, the 450D has the upper hand in this category.
7. Multi-shot self timer mode
The 450D is the first digital SLR from Canon to have this feature. This allows you to capture multiple photos every time you activate the self-timer. Imagine being able to shoot a continuous series of group shots with yourself in it - very handy indeed for photographing such moments.
8. Memory Card
The 450D also switched from the CF card (400D) format to SD. It's a good thing memory cards are not too expensive anymore because it won't be too costly to get new cards for this camera.
The new 450D looks like a real improvement over the 400D in terms of features and usability.