Speedbooster + Zeiss Contax Yashica question

D

digifruitella

Active member
I hear these vintage lenses, the "RTS" Yashica mount line are a good investment. Would they work with a Speedbooster? If so, which adapter do I need to get?

Also, if I wanted to use a Sigma Canon EF mount lenses on my GH4 then this means I'd need to own two speedbooster adapters. A Canon EF to M43 and one for the Zeiss Contax lenses (whichever mount that would be?) Is that correct?

I hear that buying up Zeiss Contax and using them with a Speedbooster is actually not a good idea, because of vignetting problems? Is that also correct?
 
The Zeiss Contax lenses work great using a C/Y to M4/3 SpeedBooster. They are also designed to cover full frame 35, so you should experience zero vignetting.
 
Sigma's 18-35mm when mounted on a EF>m4/3 Speedbooster will vignette in 4:3 stills mode (& maybe 2:3), but not 16:9.

Did not test 4K Photo Mode.
 
Bern Caughey said:
Sigma's 18-35mm when mounted on a EF>m4/3 Speedbooster will vignette in 4:3 stills mode (& maybe 2:3), but not 16:9.

Did not test 4K Photo Mode.
Click to expand...

Primarily I'm using the camera for video, but I am rather curious now just how much of a vignetting problem it is for stills? Do you have any sample pictures.

So then there's no other way for me than to own two Speedboosters, one for a C/Y and one wit EF if I want to use Zeiss and Canon lenses respectively.
 
David W. Jones said:
Well, you could use C/Y to EF mount adapters on the Contax lenses, and then use an EF mount SpeedBooster.
Click to expand...
Actually I tried doing that. There's a metal part(aperture lever?) on Contax mount that extends further into the body and won't let you use it with Speedbooster - it won't physically fit. I tried it with all of mine C/Y Zeiss lenses - 18, 25, 28, 50, 135. It will work with EF-mount cameras or other metabones adapters, but not the Speedbooster. Flange distance is too small. I took a look at Leitax, but the problem remains the same

So in the end C/Y to EF to m4/3 Speedbooster won't work.

I have the same dilemma as an op. I want to buy 18-35 and I own a set of vintage C/Y Zeiss glass.
 
AndrewTaran said:
Actually I tried doing that. There's a metal part(aperture lever?) on Contax mount that extends further into the body and won't let you use it with Speedbooster - it won't physically fit. I tried it with all of mine C/Y Zeiss lenses - 18, 25, 28, 50, 135. It will work with EF-mount cameras or other metabones adapters, but not the Speedbooster. Flange distance is too small. I took a look at Leitax, but the problem remains the same

So in the end C/Y to EF to m4/3 Speedbooster won't work.

I have the same dilemma as an op. I want to buy 18-35 and I own a set of vintage C/Y Zeiss glass.
Click to expand...

Thank you for sharing this. Then it seems that the only solution is two SpeedBoosters, one for EF and one for CY
 
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