Ok, I'm going to test this thing out today for $375. He said I could take as long as I need with it, but I can't take it home for a test run. I'll obviously look over the condition of the glass and body, test the autofocus and it's functionality, and shoot with it like I would be shooting in the field. Is there specific things I should be testing when I try it out?
Yes.
- Try its bokeh and sharpness to simulate portraiture (headshot) wide open and stopped down.
- Try macro shots from f/16 onward. See sharpness and bokeh. A tripod, or flash speedlight, would be useful for these.
- Try focusing at infinity (simulating landscape shots). Check the center and borders' sharpness at different apertures.
- Check the AF limiter function, and it's three modes: macro range AF (0.312-0.45m), normal range AF (0.45m-infinity), and full focus scale. This will make you to verify the HSM lens motor for AF.
- Check its three OS (VR) modes: off, 1 (full OS mode), 2 (panning/sports OS mode).
- Check the automatic manual override of the AF system, when AF (not M) is selected in the lens.
- Check overall image quality pleasure, zoom 1:1, see the full frame captured, etc.
Have you used a macro prime lens before? Are you aware they don't keep f/2.8 across the whole focus range, differently of non-macro prime lenses?
It is, in fact, a 105mm f/2.8-5.6 prime lens (2.8 at infinity, 5.6 at 1:1 focal distance). The maximum f stop also varies from f/22-45 (f/22 at infinity, f/45 at 1:1 focal distance). Test these values.
This is normal behavior, in case you didn't know about it. Don't panic. Basically all dedicated macro prime lenses behave this way.
Good luck!