Camer (Nikon D5100) automatically changes shutter speed / aperture - even in manual=?

Hi, I have a Nikon D5100.In manual, I can change the shutter speed and aperture to my desired settings and get a good shot, but if I immediately want to take a shot after, using the same settings, I find the camera has changed the settings. Like shutter speed may have been set at 1/50 but jumped to 1/200 after the first shot. And these settings, changed by the camera, make the picture way underexposed or overexposed. Can i change the setting so the camera does not do this and so the settings stay how I want them?

The settings SHOULD stay as you set them in manual!

I don't understand why settings are changing in manual mode!

Are you SURE you're in manual EXPOSURE mode (not manual focus for example - sorry to suggest this, but we do get some bozos on the site).

Check things like EV are on zero & Auto ISO is OFF (not that that would change settings, but just trying to get you back to full manual).

Check your metering mode too - if lighting is varying drastically across the frame, it ma affect exposure (though again, not the actual settings).

READ YOUR MANUAL properly.

Sounds like you have the focus on manual not the exposure.

A camera is not going to change parameters when in full Manual mode. Are you SURE you are not confusing manual focus mode with manual exposure mode? If the camera is in actual manual mode, you will have the mode dial on the camera body set to M, not to S or A or P or any other scene mode.

I will add that I suppose nothing is impossible, especially with any mass produced electronic device. If you truly do have the camera in manual exposure mode and it is not holding the settings you have put into it, then there's something seriously wrong with that camera and you need to contact Nikon about it.

It doesn't sound like you are in manual mode. When you set the camera in manual mode, the aperture and shutter speed never change unless you change them yourself. If this is what's going on, then there's something wrong with the camera.

It could be that you sure your not compensating for different lighting conditions. Like you move to a different location or area and keep the settings to same. If so that's your problem.

ANY camera that has a fully manual mode will NOT change ANYTHING. All the settings will remain the same until YOU change them. The only other thing I can think of is that your unknowingly bumping the shutter wheel while holding the camera or while in transit.