Modify the lens mount of Samyang/Rokinon 35mm F1.4 AS UMC

Started Dec 12, 2017 | Discussions
tingnan New Member • Posts: 12
Modify the lens mount of Samyang/Rokinon 35mm F1.4 AS UMC

I have a Samyang 35mm f1.4 AS UMC lens for Fuji-X mount. This lens was originally designed for SLRs and is later produced also for mirrorless cameras. Here is the picture for this lens:

You might have already noticed that the lens has an unusually long tube part between its aperture ring and lens mount. In fact, this is sort of an "extension tube" to compensate the flange distance difference between mirrorless cameras and SLRs. By removing the three screws I can separate this lens into two parts:

On the left, I have the lens body that contains all the glasses; on the right, we have the officially installed "lens adapter" to work on Fuji camera. So now I have an idea: is it possible to manufacture a custom adapter for this lens with a Canon EF mount?  The Canon EF version of this lens looks like this (stock photo):

As you can see the only difference between the stock photo and mine seems to be the mount part.

I am thinking of 3D printing a mount and give it a try. If that works I will try to find a good machinery store/custom adapter service to get a high precision metal version.

Let me know your opinion. BTW I know this is not cheap and probably not efficient. If all I want is a Canon copy of this 35 1.4 I can just sell my copy and by another. However, I think this is a fun thing to do...

E Dinkla Senior Member • Posts: 1,736
Re: Modify the lens mount of Samyang/Rokinon 35mm F1.4 AS UMC

A lathe and an existing EF-M42 or EF-M39 (zenith) or EF reverse adapter are probably better starting points. The first two might allow you to add an AF confirmation

chip too which I do not see on the EF mount Samyang BTW.

Met vriendelijke groet, Ernst
No photographer's gear list is complete without the printer mentioned !

Rol Lei Nut Veteran Member • Posts: 4,662
Re: Modify the lens mount of Samyang/Rokinon 35mm F1.4 AS UMC

tingnan wrote:

I have a Samyang 35mm f1.4 AS UMC lens for Fuji-X mount. This lens was originally designed for SLRs and is later produced also for mirrorless cameras. Here is the picture for this lens:

You might have already noticed that the lens has an unusually long tube part between its aperture ring and lens mount. In fact, this is sort of an "extension tube" to compensate the flange distance difference between mirrorless cameras and SLRs. By removing the three screws I can separate this lens into two parts:

On the left, I have the lens body that contains all the glasses; on the right, we have the officially installed "lens adapter" to work on Fuji camera. So now I have an idea: is it possible to manufacture a custom adapter for this lens with a Canon EF mount? The Canon EF version of this lens looks like this (stock photo):

As you can see the only difference between the stock photo and mine seems to be the mount part.

I am thinking of 3D printing a mount and give it a try. If that works I will try to find a good machinery store/custom adapter service to get a high precision metal version.

Let me know your opinion. BTW I know this is not cheap and probably not efficient. If all I want is a Canon copy of this 35 1.4 I can just sell my copy and by another. However, I think this is a fun thing to do...

Try to order the Canon mount piece as a spare part.

Though it's not certain that it would fit...

Sittatunga Senior Member • Posts: 1,467
Re: Modify the lens mount of Samyang/Rokinon 35mm F1.4 AS UMC

tingnan wrote:

I have a Samyang 35mm f1.4 AS UMC lens for Fuji-X mount. This lens was originally designed for SLRs and is later produced also for mirrorless cameras. Here is the picture for this lens:

You might have already noticed that the lens has an unusually long tube part between its aperture ring and lens mount. In fact, this is sort of an "extension tube" to compensate the flange distance difference between mirrorless cameras and SLRs. By removing the three screws I can separate this lens into two parts:

On the left, I have the lens body that contains all the glasses; on the right, we have the officially installed "lens adapter" to work on Fuji camera. So now I have an idea: is it possible to manufacture a custom adapter for this lens with a Canon EF mount? The Canon EF version of this lens looks like this (stock photo):

As you can see the only difference between the stock photo and mine seems to be the mount part.

I am thinking of 3D printing a mount and give it a try. If that works I will try to find a good machinery store/custom adapter service to get a high precision metal version.

Let me know your opinion. BTW I know this is not cheap and probably not efficient. If all I want is a Canon copy of this 35 1.4 I can just sell my copy and by another. However, I think this is a fun thing to do...

Samyang do seem to have everything in front of the red ring on that lens in common, apart from the Nikon version which focuses with a left-hand thread.

If you can actually get the bayonet as a spare part at a price that would make the conversion sensible and it uses the same screw holes it would be fun, though you might want to ask whether they use shims to adjust the focus.

The later Canon fit version of this lens doesn't have an aperture ring.  It's still manual focus but a lot less hassle to use as the camera body controls the diaphragm.  It would be much easier to sell your lens and buy the electronic Canon version.

GnarlydogOZ
GnarlydogOZ Senior Member • Posts: 1,302
Re: Modify the lens mount of Samyang/Rokinon 35mm F1.4 AS UMC

E Dinkla wrote:

A lathe and an existing EF-M42 or EF-M39 (zenith) or EF reverse adapter are probably better starting points. The first two might allow you to add an AF confirmation

chip too which I do not see on the EF mount Samyang BTW.

Met vriendelijke groet, Ernst
No photographer's gear list is complete without the printer mentioned !

I very much like the idea of the reverse mount EF adapter where one can just simply add UV filters (glass removed) to space the lens to the desired distance. The reverse mount (for macro) adapters come in different diameters and probably there is one that will fit the Samyang.  And if adding one full ring to the stack is too thick, it can be shaved by simple hand action on a sheet of sand paper (using a caliper to check even thickness). Final step: use some JB Weld (or equivalent) to bond the pieces. And if one day you want to change that mount again, a hot hair dried will soften up the epoxy glue for easy removal.

 GnarlydogOZ's gear list:GnarlydogOZ's gear list
Canon EOS R Olympus 17mm F1.2 Pro 7artisans 25mm F1.8 Canon RF 28-70mm F2L USM Canon RF 50mm F1.2L USM
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