We have had a number of users ask why the Droid screen is not being fully used for our camera apps. For those of you without a high res 854×480 screen, on the Droid the camera preview takes up about 70% of the screen, leaving a black bar to the right.
The reason for the black bar is the Droid screen is not the same ratio as a JPEG picture – 4:3. The width and height is different than a JPEG and therefore we needed to put the black bar on the screen. If we used the full Droid screen, it “stretched” the picture and distorted it. We assumed you didn’t want squished distorted picture previews.
It is the same reason when you watch a widescreen 16:9 movie on your TV screen there are black bars on the screen.