I have a backbutton image (backButton). How can I add it to the back button of the navigation bar?
UIBarButtonItem *newBackButton = [[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:@"backButton"]
style:UIBarButtonItemStylePlain target:nil action:nil];
viewController.navigationItem.backBarButtonItem = newBackButton;
[newBackButton release];
However, I am getting a weird looking button as seen below.

How can I replace the backbutton with the full black back button image?
You’ll have to modify the black image’s pixel size. Open up the image in any image editor, go to the adjust image size (it may be called something else in a different photo editor) find out the size and pixels. It looks like you’ll have to make the thing 1 pixel taller and like 2 pixels wider, but I’m not sure. You can probably find some documentation on the exactly pixel size of the navigation button and work with that. Goodluck