EOS R6 Mark II not communicating with Samyang EF 85mm MF lens

[EduardoMercado]

Hi, I have an EOS RP and have been using a Samyang XP 85mm f1.2 manual focus lens with an EF mount with no problems using an original Canon EF to RF adapter. I recently bought an R6 mark ii and when using this same adapter and lens, the place where the aperture is displayed disappears and taking a picture leads to a black screen that does not go away even when turning the camera off. If I take the lens and adapter as they are and use them on the RP, they work again. Other lenses work fine on the R6mii so I don't think the pins are damaged (plus it is brand new).

I have tried turning on the Release shutter w/o lens and turning the stabilization off with no success. 

Any help would be well received.

[Danfaz]

I looked through all the R5 firmware updates (see link below), and do not see any mention of fixing issues with Samyang/Rokinon lenses. I doubt they would, considering they asked Samyang to cease making AF RF lenses.

https://www.usa.canon.com/support/p/eos-r5#idReference%3Dadvisories

[David-R-M]

I bought the Samyang because at the time there was no equivalent made by Canon. However, as I have read, Canon does not seem to encourage third-party equipment, whilst other camera manufacturers regard having third-party lens available makes their product line more attractive. I am not even sure that Canon publishes their communications protocols, which might explain the current mismatch as third party companies presumably have to work out the protocol by trial and error.

I see that Canon now sell a very cheap16mm f/2.8 RF lens, which is probably the best way forward as for occasional use I don't need an "L" lens. Still, it is annoying to have a lens in "as new" condition which won't work due to what is probably a minor firmware bug...

Of course, as my Canon RF lens all work perfectly on the R6MkII, the responsibility must ultimately lie with Samyang. However, my attempts to find the address of a support service from Samyang have so far all failed (and of course the lens is out of guarantee by four months).

P.S. Somewhere on a web site (DP Review?) I read a report from someone who said that an R5 update stopped his Samyang lens working, but a later update (I think he mentioned 1.3) fixed it again. Clearly, Canon didn't mention Samyang in the release notes.

[roscografik]

The same, I have the 85 f/1.2 XP, it worked perfect on my RP and sadly no more on my new R8. If anyone here experimented an update on this lens I'd be happy to hear from this ?

[Waddizzle]

The fully manual lenses do not communicate with any camera bodies.  If you look at the lens mount and do not see any contacts, then your lens is fully manual. 

[David-R-M]

I note that the Samyang 14mm F2.8 is in principle fully compatible with the R series and has auto-focus. This may not be the case for the 85mm. However, I found that by loading the latest firmware version into the lens it worked correctly, but only for a certain time. My conclusion is that there is a problem with the memory in which is stored the firmware, because I could fix the problem temporarily by reloading the firmware once more. However, as the lens is out of guarantee I decided that I had  invested enough money, and far too much time, so bought the Canon RF 16mm F2.8. Unfortunately this had not been available when I bought the Samyang. Thus, I now have a very expensive paer-weight!

[roscografik]

Hi, it's a manual lens with contacts because aperture is driven by the camera (you only have a focus ring on the lens, no aperture ring)

[EduardoMercado · Accepted solution]

I was able to solve the problem. I flew to South Korea and took my lens to the customer center. In a matter on 5 minutes they updated the software in the lens and it now works flawlessly with my R6 mk ii.

Before that, my provisional solution was to cut out a ring of very thin but sturdy plastic and insert it in my EF-RF converter between it and the Lens. This blocks the contacts so the camera does not even try to communicate and as long as you enable the shoot without lens in the menu, you can use it fine (with no aperture control). To select my aperture, I put the lens on an EF body, select the aperture and detach it with live view enabled. The blades will stay at this aperture until it is connected again to a body with contacts. 

[David-R-M]

It is possible to update the lens firmware at home in a few minutes if you buy the USB interface. I expect that this would be both simpler and cheaper than flying to South Korea!