Hi Greg;
Sorry for the late reply. I do not often check this box, usually, messages comes in the PM inbox.
1 & 3. I don't know hot to describe the "white spot mark". They are like specks on the coating. I don't see any effect of them on the photos. If you send me your email address, I'll forward some pics of the specks themself and photos taken with the lens.
2. Tripod ring bought from ebay . Works OK.

Nick

Some questions about the Adaptall 80-200 for sale:
1. How big are the "white spot marks" you mentioned? I couldn't tell from the picture. Do they ever show up in photos?
2. How snug/secure is the 3rd-party tripod ring? Can you easily rotate the lens 90 degrees to shoot vertical on a monopod?
3. How sharp is this lens wide open? How's the contrast?

I currently use a Vivitar Series 1 70-210 f/3.5. I like it very much; it's sharp and contrasty wide open. I use it for night-time HS football, coffeehouse concerts, etc.

The only reason I'm considering another lens is:
1) To get something even a little faster (f/2.8 vs. f/3.5), and
2) to get a zoom with a tripod ring. There's not really any good place to mount a tripod ring on the Vivitar, at least not without losing the range around 150mm - 210mm.

Thanks for any additional info!

Greg