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Sigma SDQH is changed to canon EF and can auto focus

Started Oct 8, 2018 | Discussions thread
OP mengaza Regular Member • Posts: 172
Re: Sigma SDQH is changed to canon EF and can auto focus
  1. docmaas wrote:

Sigma uses the same protocols and register as canon ef and basically the same mount as pentax ka. I'm still not convinced that image stabilization is functional on a canon lens using a sigma camera but not having a lens I can't test it. I do know that in the past it has not worked when the mount on a canon image stabilized lens was converted to a sigma mount even though the contacts were lined up correctly. I assumed that when sigma developed their own image stabilization they used different protocols for their canon mount lenses than they did for the analogous sigma mount models and that led to an incompatibility between Image stabilization on the two mounts that could only be resolved by switching lens chips.

As it turns out I do have a 16-35 f4 Canon IS lens and Image Stabilization does not work on the lens on my quattro. Of course the lens may be faulty and since I have no canon body I cannot test that possibility.

I texted to Wei Duan, the fellow who did/does the work, and his response was that the 35mm f2 works on the converted camera but I was unable, due to language difficulties to penetrate to a yes or no on the IS functionality. I'm sure I could sort it out if I could talk to him but there is no voice feature in aliwangwang the texting feature I used.

Maybe, it's time for another trip to China.

Mike

rf-design wrote:

mengaza wrote:

Lens exif info (focal length, F value) are in raw and jpg file

That could only mean that Sigma copied the hole protocol and message fields from the Canon-EF to use in there own SA-mount electrical interface.

Or is there a protocol converter, small integrated circuit on a board, built somewhere?

The lens that I mention have green cast problem, I'm not so expert in post production, I can't correct color.

Now I can't compare because of my 8-16 in SA mount. From my feeling tokina give brighter picture and a little bit sharper.

This week I'm busy and not in my home. Next week I will make a video to show IS of canon work on my sdqh and will post in YouTube.

 mengaza's gear list:mengaza's gear list
Sigma DP2s Sigma DP1 Merrill Sigma DP2 Merrill Sigma DP3 Merrill Sigma dp0 Quattro +9 more
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