Anyone ever find review of Sigma lens ON a SIGMA BODY?

I keep looking but have never found this anywhere. It seems like an obvious thing to be curious about yet dead silence in the review-o-sphere.

So many reviews of Sigma lenses find erratic focusing to be an issue.

Sheer guess-ery is rampant in forums, when people attribute this erratic behavior to either 1.) bad quality control/design, or conversely, 2.) software problems due to difficulty rigging something so 3rd party lenses autofocus on Canon (or Nikon) bodies. A test to prove which (if either) of these is the culprit would be read with interest by lots of people with major brand camera bodies trying to decide whether to buy into the love-fest and pick up a Sigma Art lens.

Obviously the review would be of more interest if the Sigma lens tested were the much talked-about 35 Art or 50 Art rather than "lesser" Sigma models.

I found several samples when searching for "sigma 35mm f/1.4 on sigma sd1", however the first result, a LensRentals SD1+35mm Art kit probably explains the lack of reviews best.

A ~1.1 second (7 shot) burst buffer, noise becoming "prevalent" past ISO 800, and, lack of support ("Note: If you shoot RAW, you must download and use Sigma Photo Pro to convert your files to .TIFF and then export them to the software of your choice, as main stream programs such as Aperture, Lightroom, Photoshop, Capture One, etc. do not support the Sigma SD1 Merrill. Or you can use the Sigma Photo Pro software to tweak your image, though it can be slow and lacking in features when compared to other programs. Once again, YOUCAN NOT OPEN IN APERTURE, LIGHTROOM, ETC. WITHOUT CONVERTING THE IMAGES IN SIGMA PHOTO PROFIRST.") all likely contribute to people ignoring the combo.

Hi. But my particular interest is the constantly repeated claim that Sigmas have dicey autofocus, and that this AF issue may be caused by some kind of communication problem between the Sigma lens and the (Canon, Nikon, etc.) OEM camera.

I would like to see someone compare the hit rate on a Sigma-Canon setup vs. a Sigma-Sigma setup in the same shooting conditions to see if there is any difference. Obviously there would be the factor of the two different bodies and the different AF systems, but it would still be the first time anyone ever tried it and had any data on the subject of whether any AF issue is likely at least in part a result of Sigma having to reverse engineer firmware to the Canon body's AF. I think it would be relevant, particularly if the two bodies were of approximately similar AF ability (Not a 1Dx vs. a Merril).

I was thinking that TDP would be a logical authority on this because it is a respected source of reviews, and because its own reviews of the Sigma lenses have often speculated that some communication issue may be operating to give erratic AF. I could also see this being something Roger at Lens Rentals would find curious enough to investigate.

I think that because Sigma has such a small percentage of the DSLR market that their lenses' performance on Sigma bodies is irrelevant. Sigma isn't selling very many Sigma-mount lenses. Therefore, it only matters what a Sigma lens can do on the Canon and Nikon bodies that they are actually being sold for.

Knowing that a Sigma lens performs better on a Sigma body is quite irrelevant if you have a Canon or Nikon DSLR, at least from a consumer's perspective.

For what it's worth, I plan on using the Sigma 35mm f/1.4 Art and 50mm f/1.4 Art lenses as my primary tools to photograph an awards banquet tonight. I know their AF consistency isn't quite as good as some Canon lenses, but overall, they're good enough to be relied on in most situations. And when in doubt, using the center AF point (and recomposing) seems to be the best method for dealing with most of the AF issues I've experienced.

Hi Sean. Good point about the Sigma body comparison being of direct interest to few people due to the tiny market share for Sigma's bodies.

I too have a Sigma 35 Art, and it is a close second favorite to me, after my 70-200.

I am not doing a good job of explaining it, but what I was saying is that if there is a tendency towards erratic AF in Sigma lenses on OEM bodies, then what is the cause? Assuming it does exist, Is it a.) generally bad manufacturing QC, or is it b.) the problem of getting the firmware to work with OEM firmware. People speculate either way. It would be interesting to me at least to see a side by side test to at least she's some light.