Originally posted by lotech Thank for the tips, do you have the link for the Sigma APO ?
No, but I have an old lens test from german 'photomagazin' and I have made my own testings.
If you can find one:
take in Hands, handle it - I'm quite shure, you'll buy it!
(if not too pricy)
The AF-Version is not built the same way and - perhaps because of less tight fixing of the lenses due to AF - optically not exactly the same class even though the constuction should be identical.
The 50-200 was (one of) the first APO-lens(es) by Sigma and for the Prices in those days (80's) very pricy for a brand like Sigma.
(Their reputation wasn't that high as it's nowadays.)
Therefore these manual focus APO-lenses from Sigma are not to be found that often....