[KevinR]

Before I bought my first super-tele (>>300mm), I scouted the internet, but options are somewhat limited here in South Africa. The main options being Sigma 50-500, 150-500, or old stock 170-500. The general indication was that the 170-500 was ok, but somewhat soft above 400mm.

I ended up buying the Sigma 170-500 mostly because I needs something longer than 300mm for birding and the price was right, and the advise was that optically the 150-500 was not a major improvement. Last week I lucked upon a second-hand SMC-Takumar 500mm f/4.5, a Sigma 70-300 APO, extension tubes and monopod all together at a price I could not let slip.

I tested and compared the Takumar against the Sigma 170-500 over the weekend, and perhaps I have a problem with the Sigma, but the Takumar so far is a dramatic improvement ito sharpness.

Thought I'd put it out there; but also to check if anyone has a view if the Sigma is really delivering the best it can, or if I perhaps have a problem with the Sigma 170-500.

Regards
Kevin

Comparison cropped to small area from center of image:

Takumar and Sigma original image factors

[Canada_Rockies]

I tried the Sigma 170-500 on my MZ-S and found it soft compared to my M 400/5.6. I sold it off at a loss despite the convenience of the zoom feature and the AF.