Sigma 50mm f/2.8 macro

Sigma produced this lens in manual focus mount from 1989-1995. It is a true macro lens capable of focusing down to 1:1 magnification. The lens is very large and heavy for a 50mm lens, 320 grams (12oz) or a bit more then a zuiko 50mm f/1.2 lens. The lens is claimed to be exceptionally sharp, sharper then most OE manufacturers. I’ll test this out when I have the chance. From my use so far the lens is extremely sharp with no evidence of chromatic aberration or distortion.

Infinity focus

The lens consists of 10 elements in 9 groups and is multicoated. It has a filter diameter of 52mm. The lens has a maximum f/stop of 2.8 and a minimum f/stop of 22 with detentes every half stop. The diaphragm has 7 blades. The lens is 66mm in diameter and 57mm in length at infinity (significantly longer when focused to 1:1). The lens weighs 310 grams. As mentioned before the lens focuses down to 1:1 magnification (about 4 1/2″). Focusing from infinity to 1:1 takes about a 3/4 twist of the lens barrel and focusing is relatively easy.

1:1 focus

I felt that it might be nice to compare the Sigma 50mm f/2.8 macro to the Zuiko 50mm f/3.5 and zuiko 50mm f/2 macros as the Sigma has the same focal length and falls almost in the middle for lens speed.

Sigma 50mm macro | Zuiko 50mm f/3.5 macro | Zuiko 50mm f/2 macro

Length: 57mm | 40mm | 55mm

Width/filter: 66/52mm | 60/49mm | 69/55mm

Weight: 310g | 200g | 320g

Reproduction size: 1:1 | 1:2 | 1:2

The Sigma is larger/heavier in all respects then the zuiko 50mm f/3.5 and only wins out in being 2/3rds of a stop faster and being able to achieve 1:1 reproduction size. The Sigma ends up being a full stop slower then the zuiko 50mm f/2 and very slightly longer (2mm), but it also ends up being slightly narrower and slightly lighter while also going to 1:1 instead of 1:2. If size and weight are an issue then the zuiko 50mm f/3.5 is definitely the champ, if speed is a requirements then the zuiko 50mm f/2 would win, but if it is reproduction size or possibly just a compromise between several different things then the Sigma 50mm f/2.8 wins. For image sharpness, distortion or CA, I have no idea until I can get copies of the zuiko lenses to test with (if I ever do).

As for cost, I managed to get my sigma 50mm f/2.8 for $50, about half or a little less then what the zuiko 50mm f/3.5 macro usually runs for and a very small fraction of what a zuiko 50mm f/2 macro generally runs for.