Hi everyone. I'm very new at this and my focus is mostly Pet, Animal and Landscape photography. I'm using a Nikon D70 with a Quantaray 70-300mm (in these shots). I pretty much at this time point and shoot, cuz I haven't gotten books on how to use it yet. But the problem I'm having is, when I press the button halfway it focuses, then I press all the way to take a pic and it doesn't always take the pic. It's very frustrating. Is this something that reading a book will reveal the answer? I know, dumb question. I just want to be sure it's human error and not something mechanically wrong with it.