I have the older Sigma 90/2.8 macro. It is very good lens with good performance on all apertures at infinity. At medium macro magnification it is extremely sharp. The problem is the slight incompatibility with EOS 5, the rotating focus and filter rings and max magnification 1:2.

I have now purchased the new Sigma macro. For Sweden a fantastic price, SEK 3125 = $ 410 (Bjorns Foto, Varberg Sweden)

• longer focal lenght = better working distance
• goes to 1:1
• very good mechanical construction
• no EOS compatibility problem
• clutch mechanism to disengage focus ring in AF
• non-rotating filter
• very good manual focus feel - much better than any (non-L) Canon lens!!!
• focus speed and noise tter than old lens apertures to f/45
• 58 mm filter

• Both AF/MF switch and cluctch mechanism on focus ring
• No ultrasonic motor

I have tested the lens (S105) against my other 100 mm lenses, EF 28-105 (C105), EF 100-300 (C100) and Sigma 90/2.8 (S90).

C100 best, then S105, then S90, C105 soft. Note f/4.5 vs f/2.8.

S105 best, then S90, then C100 and C105 soft. Sigma much better!

All almost equal but S105 slightly better

S105 best, then S90, C100 and C105 soft. Sigma much better!

S105 has a focus distance of 48 cm vs 41 cm for the S90.

Results are very similar. Maybe maybe the S90 is slightly better.

Slight at infinity wide-open, lower at 1:1. Gone at f/8.

Note that Canon EF 100/2.8 has high vignetting wide-open at infinity but low at 1:1.

Linear distortion not detected.

Conclusion is that this new macro lens is very good. I really like the feel of the lens. It is a pleasure to operate it. It rate the handling and mechnical construction higher than Canon EF 100/2.8 and Tamron SP 90/2.8.

I can definitely recommend this lens which also has a lower price than the other two.