When these 50mm and 85mm
When these 50mm and 85mm Sigma EX lenses were released, they were very popular because the design was an improvement over the traditional Gauss derived models that Canon and Nikon had not yet updated. Over time and especially with the "next step" Art series lenses that Sigma subsequently released, these EX primes faded into the background. They were most notable for better central contrast and resolution at large apertures, than the Nikon and Canon equivalents, so they were favoured by photographers that prized these qualities. The edge performance was decidedly worse - especially at large apertures. That is where using these lenses on an APS-C sensor gets very interesting. The central full frame performance becomes the total frame on an ASP-C camera, so you essentially get "art series" quality images on these smaller sensor cameras. The penalty of the large size and extra weight of these lenses is compensated by the greatly reduced vignetting on the APS-C format. Now that these F 1. 4 lenses sell for less than the Canon and Nikon F 1. 8 lenses - you should give them a close look - especially for high quality APS-C portraiture work. Gosselin's used department gives you a professional inspection, a warranty, and excellent after sales service that you do not get with a private sale. I highly recommend Gosselin as the best option to acquire used gear.