And how does the pentax a 70 210 perform on a digital?

or would I be better off buying a 50-200 for my digital and buying a 200mm f4 for my k1000? (since for analog, I already work with primes only..) and I've seen them for low prices as well.
chr

the vivitar specs are correct. You can see what I mean on this page:

http://www.robertstech.com/vivitar.htm

I have my eye on an auction for the 3rd version. But you can see that is is a little bit heavier than the pentax 70-210 and has no built in lenshood..

The idea to get an old 70-210 is because it fills perfectly the gap I have for my analog camera (as I only have primes up to 100mm). and for digital is nicely fills everyting above the kitlens (105 to 300mm).

The DA 50-200, I believe is not something useful for my analog system (fully manual and this lens has no aperture ring...)
chr

I am looking for an additional lens to complete both my k100d and continue
with my k1000 as well.

I noticed that there is quite an availability for the pentax A SMC 70-210mm
f4 on the internet at very reasonable prices.

The other alternative I see is a vivitar 1 series (3rd) 70 210mm f2.8-4.
Seems that this lens (according articles) delivers very good optics.

Since I havenot use any of the two, I doubt on whcih one is the better
choice.
The pro for the vivitar seems to me the f2.8, but unsure if the comparison
is correct. the Vivitar seems also a bit heavier...

thoughts?
chr