Sigma have really decided to step up their game. According to an article today on photoclubalpha.com, Sigma will be streamlining their product line by bringing all lenses to their former "EX" standard. Additionally, they have made significant changes to their QC and standards testing. Graham Armitage of Sigma, UK, made the announcement at Photokina.
“Our greatest breakthrough is in MTF testing. We no longer use the Zeiss MTF equipment we have used in the past. It was too limited in resolution and could not provide data to match today’s sensors. Each test used to take at least half an hour, so we would pull a lens from the production run at random, and test that. We have always tested actual production lenses but only one in every so many.
“Now we have built our own MTF testing system, based on the 46 megapixel Foveon Merrill sensor used in the latest cameras. This allows a much better MTF test and we can put a lens through in just five minutes. As a result, we have started testing all the lenses produced, not just a sample. In future any Sigma lens you buy will have been MTF tested and certified.”
Another very interesting item concerns "re-chipping" of lenses. All future lenses will be compatible with a special USB dock, and will allow firmware upgrading in the field.
“It does more than just upgrade the chip”, he continued. “With a PC program, you will be able to change the focusing speed of the lens. All AF systems are a compromise, a balance between speed and accuracy. You will be able to set the lens to suit your working style, increasing the focus speed if you shoot action or improving accuracy if you take subjects like landscapes and portraits.
“All DSLRs have problems with front and back focus. Some cameras offer AF calibration, but not all allow you to have different corrections for each focal length of the zoom lens and for different focusing distances. Using our program, you will be able to calibrate new Sigma lenses for the full range of settings so you don’t get front or back focus at any distance or focal length.
“Not only that, with new telephoto and macro lenses you will also be able to change the distance ranges used by focus limiter switches.”
When queried about the price of the USB dock, the estimate was in the $45 range. This is huge! Being able to fully tweak a lens to mate with your camera and your style of shooting is really exciting and a huge benefit. It further solidifies my decision that any new lens I buy will be a Sigma -- unless it's an old Minolta...