Henry: > I've seen a Vivitar 70-210 (or possibly 70-200) f3.5. Whilst not > a constant f2.8, f3.5 seems quite reasonable. At a price of 35 > GBP (55-60 USD I guess), is this a worthwhile purchase?
There were two Vivitar S-1 70-210/3.5 models (first with 67mm filter threads, second with 62mm). I owned a second-generation (62mm) one for a number of years back in the 80's, and it worked well for me, despite being subject to a lot of abuse (it was my "road lens" at the time - <g>). I'd say that 55-60 USD is a pretty good price, if it's in very good condition. I would make certain to check for lack of play in the zoom/focus action - my old 70-210/3.5 eventually developed a looseness there (but, as I said, it was not treated all that well). > Also, does anyone know what the Pentax T6-2X is like in comparison > with the A 2X-S? I've tested them side-by-side carefully once before, although with them mounted to an A* 300/4, rather than to a 70-210 zoom. I had a ~very~ difficult time telling the results apart (looking especially for edge resolution and for vignetting), but found the 7-element A 2X-S to be ~maybe~ just a very ~tiny~ bit sharper than the 6-element T6-2X. However, despite this ~very~ slight possible difference, I still prefer using the T6-2X, since it is almost as compact as the little A 1.4X-S (and is definitely shorter than the A 2X-S), and thus is much more in keeping with the compactness of the A* 300/4 itself. However, the Pentax literature might steer you toward using the A 2X-S with a 70-210 zoom: The T6-2X is specified for K-mount prime lenses between 135mm and 300mm, and while it can probably be coupled to shorter or longer lenses, or used with various zooms, Pentax does not recommend doing so. On the other hand, the A 2X-S and A 1.4X-S "are usable on almost all Pentax bayonet mount lenses". Of course, if you would be using the 70-210 zoom with the T6-2X at 210mm (for an effective FL of 420mm), the stated limitation for the T6-2X of 135mm and longer might not apply. Fred - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
