Using the high speed film is probably your first mistake. If you are blowing
this stuff up to 8X10 you are going to begin seeing grain with 400 and
certainly with 800. Taking pictures of animals is certainly made more difficult with
a slower film asa 50-or 100. But that's what making wildlife photos is all
about and why many serious nature photographers use fast lenses. That's not to
say you can't do it with slower, cheaper zooms. You just have to be very
careful. Use a 100-speed film. Take off the doubler and work harder on getting
physically closer to your subject either by finding subjects that are less skittish
(in parks, or other areas where they are in close contact with people), or
using some type of blind (your car can work nicely.) No one said it is easy
getting good wildlife shots. It's possible with the equipment you own just a
little harder....
Vic