maximum capacity for nikon D50 is 2gb, try use lower capacity, if error still appears, bring it to your local service center, possibility of hardware problem
If you're in manual mode, you have to press the (+/-) button and then rotate the command dial at the same time. This will allow you to lower or raise the aperture f-number.
Hi
Have you tried resetting the camera back to factory settings? This should clear up any problems...if it doesn't it may at least let you know what the problem is? Also...do not use an SD card no bigger than 2 gigs, What is thee display showing? Make sure the date and time are correct! Get back to me if you need any more help...Thanks...John,