Originally Posted by
NorthernFocus
Welcome to CiC, Sandra. Your photo isn't showing in the post but this is a common problem and I can guess what it looks like. You indicate that you are shooting in manual mode but are you setting ss and f-stop based on what the camera meter is telling you? And do you have the meter set to matrix metering(or whatever Canon calls it)? If so than you are under exposing the black dog because the meter is reading things that are much lighter in color therefore under-exposing the black subject. Start by setting your camera to +1 exposure value. IOW per above if the meter is telling you at ISO400 to set 1/1000, f8, then try 1/500.
Your camera should have an exposure compensation(EC) setting(or whatever Canon calls it). Generally speaking when shooting black/dark subjects you should set EC to +1(increase exposure) and for white/light subjects EC set to -1(decrease exposure). If shooting in manual mode the EC setting adjusts the meter output that you are looking at. If shooting in A,S, or any other auto mode, the EC setting will adjust the camera settings.
Hopefully this will get you started and point you down a path of learning/improvement.