Vignetting shouldn't be as obvious on a short lens, generally.
Experiment a little. Put the camera on a tripod and shoot a full roll at the exact same subject (and keep note of which frame number had which setting for when you want to compare.)
By the way, this is not very useful if you shoot prints, as the development process will "correct" for errors. But if if you scan the negatives or shoot slides, the difference should come out.
I recommend you do this with very fine film, so that you can tell the subtle differences. K25, Provia 100, Or Velvia.
Try this. At the longest focal length, (300mm on yours), shoot the following (let the speed adjust automatically):
- a shot each at f/5.6 (largest setting), f/8.0 and f/16
- set exposure compensation to +1.0, and shoot 3 pics at f/5.6, 8.0 and 16.
- set exposure compensation to -1.0, and repeat.
So you'll have 9 reference shots at 300mm
Then repeat the same process at 28mm, 50mm, and 150mm. That should make you 36 shots in all.
When you compare, you may find the following:
- Vignetting is more apparent when slightly underexposed.
- you f/8 shots should be clearer, with more detail than other apertures.
I'll let you make your own discoveries after that. There are plenty to see.
The important thing here is that you will learn about the impact of different apertures and focal lengths, as well as the impact of under/over exposing. (underexposing in the right conditions, for example, can make the sky very dark. that's what I did for the 737 shot I posted above).
The only thing you should feel when shooting a terrorist: Recoil.