You don't need to zoom in to take close up shots. You need macro lens
capabilities. If you have a fairly new digital camera, then you should
have a macro setting. Look for a small flower icon somewhere on
your camera. On my camera, it's the lower part of the browse wheel (6 o'clock). On some
cameras, there might be a macro setting you have to turn a setting knob
to.
To use the macro feature, push the button with the flower icon, or
turn the knob to the macro position, which should also bear the flower
icon. You should have the lens pulled back all the way. If you zoom in, the pic will be blury. Depending on how old your
camera is, and how many mega pixels it can shoot, in the macro setting, you should be able to move in as close
as two inches to your subject, or even closer and still get a clear shot.
As for the problem, you might try removing material from both the
shoulder and the pack, to try and have them "meet in the middle".
Remember that soft things yield to hard, so the pack will conform to
the shape of any harder stuff, like armor, but soft clothing will often
yield to the harder fabric of a pack and the hard stuff inside it.
You might try to resculpt some detail with epoxy putty.
Though if it doesn't look that bad, perhaps just repositioning the pack is the best way to go.