Strange question Canon telephoto on MF Back.

[Marlyn]

Odd thought I had, that may be a 'what am I smokeing' question,  but here goes.

Assuming such an adapter existed for the mounting...
Is it technically possible, to focus a Canon TelephotoLens onto a Medium Format back ?    Such as a 500 f4 or 800 f5.6 ? (even at a reduced image circle).

If it IS possible, What issues would need to be overcome to make it work (Shutter springs to mind for a start).

Regards

Mark.

[Graham Mitchell]

Yes it is possible, and the camera you need already exists. In fact there might be several options. Here's one:
http://forum.getdpi.com/forum/showthread.php?t=28197

[Stefan.Steib]

Mark we have tested this on our HCam- B1, as I am frequently on Roadshows where Canon also exhibits (Next Canon Roadshow in Germany we will also attend)
I was able to check the full  product portfolio of their long Prime teles. It works but with the following restrictions:

Depending on the make of the Barrel and the depth of the back lens inside this barrel, the Mount will vignette.

I have tried about all the Canon Prime Superteles and they all have an image circle of usable 40mm coming through, but not more.
I am sure the actual Image circle would be MUCH bigger, so if someone would want to slaughter such a lens and let a M645 mount put on it I think this would be
(theoretically - and if Money is no concern) possible.

What is working much better are Zooms. I personally have a 70-300 Contax N1 Vario Sonnar with Conurus conversion which draws the full image
(even for 80 Mpix!) circle up to 300mm (with a bit of corner vignetting at 70-90mm).
Now depending what Zoom you may get for this (they all have reduced flange focal distances for the Teles) this may work very well.
Candidates for this may be the :
SIGMA APO 50-500mm F4.5-6.3 DG OS HSM (not yet tested)
Sigma 150-500 F5,0-6,3 DG OS HSM(not yet tested)
Canon EF 200-400mm 1:4L IS USM EXTENDER 1,4x
The Canon with the extender is definitely a hot candidate for a full coverage as the extender is actually enlarging the image circle.
I had the idea to use the extenders as a standard on the long Primes and see if this wold bring the full coverage.(not yet tested)
Actually what Hasselblad does with the HTS adapter is exactly this - enlarging the image circle with a teleconverter and use it for Shift tilt.

So there is still a lot to experiment. 

Greetings from Munich
Stefan

[theguywitha645d]

If you can put an R-series lens on an S2, then it could be possible with a Canon telephoto:

http://www.reddotforum.com/content.php/176-Testing-the-Leica-400mm-APO-Telyt-Modular-R-on-the-Leica-S2

[Stefan.Steib]

The Leica R lenses are all very good and most of them have huge image circles.
We have used several of these on the HCam already.

As I said, removing the 35mm mount and open up the barrel to mount on a 645 will help also.
The Leica S2 chip is not especially big, only 50 % larger than a 35mm full format that also makes it easier.

Regards
Stefan

[theguywitha645d]

I don't think the OP specified the back. There are MF 40MP sensors by Phase/Leaf, Hasselblad, and Pentax that have essentially the same sensor size as the S2. A few sensors are a tad larger and a few even larger.

[Harold Clark]

Mark we have tested this on our HCam- B1, as I am frequently on Roadshows where Canon also exhibits (Next Canon Roadshow in Germany we will also attend)
I was able to check the full  product portfolio of their long Prime teles. It works but with the following restrictions:

Depending on the make of the Barrel and the depth of the back lens inside this barrel, the Mount will vignette.

I have tried about all the Canon Prime Superteles and they all have an image circle of usable 40mm coming through, but not more.
I am sure the actual Image circle would be MUCH bigger, so if someone would want to slaughter such a lens and let a M645 mount put on it I think this would be
(theoretically - and if Money is no concern) possible.

What is working much better are Zooms. I personally have a 70-300 Contax N1 Vario Sonnar with Conurus conversion which draws the full image
(even for 80 Mpix!) circle up to 300mm (with a bit of corner vignetting at 70-90mm).
Now depending what Zoom you may get for this (they all have reduced flange focal distances for the Teles) this may work very well.
Candidates for this may be the :
SIGMA APO 50-500mm F4.5-6.3 DG OS HSM (not yet tested)
Sigma 150-500 F5,0-6,3 DG OS HSM(not yet tested)
Canon EF 200-400mm 1:4L IS USM EXTENDER 1,4x
The Canon with the extender is definitely a hot candidate for a full coverage as the extender is actually enlarging the image circle.
I had the idea to use the extenders as a standard on the long Primes and see if this wold bring the full coverage.(not yet tested)
Actually what Hasselblad does with the HTS adapter is exactly this - enlarging the image circle with a teleconverter and use it for Shift tilt.

So there is still a lot to experiment. 

Greetings from Munich
Stefan


Along the same lines, have you tried the Canon 24 TSE with 1.4 extender? I thought this might produce a quite useful image circle, providing the quality holds.

[Peter Devos]

The Canon 24mm TSE mk2 can be used fully shifted on a 50Mp sensor. 

[Stefan.Steib]

I have a customer who uses his 24 TS-E with a 1,4 teleconverter and although I have not seen his Images he swears this works perfectly.

Regards
Stefan

[uaiomex]

Count on that. I use my 17TS with a TC1.4X with shifts and I have to carefully pixelpeep to find some differences. BTW, my TC is not the very latest.
Eduardo

I have a customer who uses his 24 TS-E with a 1,4 teleconverter and although I have not seen his Images he swears this works perfectly.

Regards
Stefan