[avid1]

Hi all


I bought the SMC Pentax-M 35mm f/2.8 lens with a K mount without thinking if it can be mounted on a Canon FF body, a 5d MkII to be exact. The lens mount has a tab sticking out. See red arrow in attached image. Is there an adapter to go from the K mount to EOS FF cameras leaving the tab intact, or does the tab have to be removed to use the lens on a EOS body? The lens is too beautiful, I couldn't butcher it. But I would also like to use it. Any thoughts?

Thanks in advance

Attached Images

 

[pepperberry farm]

buy a good, used K-5 IIs and use it...

[Lowell Goudge]

buy a good, used K-5 IIs and use it...

maybe even a used K1, for full frame. if pentax lenses are such an attraction, why not use them on a pentax FF body. but given the registration distance is about 1.5 mm less for the canon lens it may or nay not hit the mirror. this was always the issue with canon

[stevebrot]

The lens is too beautiful, I couldn't butcher it. But I would also like to use it. Any thoughts?

Welcome to the Pentax Forums!

You are so kind to not butcher the lens. It looks to be a particularly clean copy. Adapting Pentax and Nikon to Canon FF has a long history of difficulties, usually in the form of gross interference with the Canon's mirror by the rear element and/or various hardware on the lens rear. Your options are simple:

• Sell the lens for what you paid for it and adapt an M42 lens instead (most will not challenge the mirror). Conventional wisdom on this site would suggest the Super Takumar 35/3.5 as particularly good.
• Try the lens on a crop-format Canon (has shorter mirror)
• Buy a mirrorless camera as host for this and other adapted lenses
• Buy a Pentax dSLR to use with the lens. Stop-down metering works pretty well with the M-series lenses and the cameras are nice too.
• Buy a K-mount film SLR and use the lens on it. All but the Pentax *ist (film version) are compatible.

If it were just the rear element, there would also be the option of shaving your Canon's mirror to fit.


Steve

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Last edited by stevebrot; 02-26-2019 at 09:16 AM.

[Just1MoreDave]

There are small screws in the silver part of the mount, just below the flanges, something like #000 size. Unscrew those and the black light shield can be pulled out of the mount. Then only the lever remains. That could be removable but I think it is a larger stamped steel part that is integral to moving the aperture blades. I might consider carefully bending it, less destructive than cutting. Probably you'd need a substitute light shield.

[jlstrawman]

pentax k to canon 5D adapter - Google Search

[Not a Number]

The Fotodiox adapter comes with a warning that it is not compatible with Canon FF and some APS-C bodies.

Pentax K SLR Lens to Canon EOS Mount SLR Camera Body Adapter ? Fotodiox, Inc. USA

Compatible Cameras
Canon EF-s (APS-C) System Cameras Only:
7D, 10D, 20D, 30D, Rebel xt, xti, xs, xsi, t1i, T2i, T3, T3i, T4, 300D, 350D, 400D, 450D, 500D, 550D, 1000D

NOTE: This adapter will not work on full frame EF cameras (such as Canon EOS 1D,1Ds Mark II III, 5D, 5D mark II, etc) and select APS-C cameras (40D, 50D, 60D, 60Da), due to how the adapter sits inside the camera body.

As suggested above it would be better to use a compatible APS-C, mirrorless, a Pentax or other K-mount body.

Cutting off the lever and shield will impact the resale value and functionality on K-mount bodies of the lens. Bending the lever may not work as you would have to bend it away from the mirror so it may likely hit the walls of the mirrorbox. Even if you straightened out the lever it would show the effects of bending and thus lower any resale value.

[Papa_Joe]

A good friend of mine has a Canon FF and is shooting all sort of lenses with it. For using Pentax bayonett mount (PK) lenses there is only one possible solution:

1. Remove the black shield as Just1MoreDave has shown.

2. Cut of the lever.

If you just want to try out a lens you can use the live view. Switch the Canon to live-view BEFORE mounting the lens! Take lens and adaptor of the camera BEFORE switching back!
And I will take no responsibility if you smash the mirror!

[Not a Number]

Another solution I've seen online is to cut down the mirror on the camera. If you don't like that idea imagine what Pentax owners think about cutting the lever on a perfectly good lens.

[avid1]

Another solution I've seen online is to cut down the mirror on the camera. If you don't like that idea imagine what Pentax owners think about cutting the lever on a perfectly good lens.

Ha, great advise with the mirror!!! Perhaps it will put you at ease to know that I give the glass more importance than the dark box it precedes, especially the digital kinds with short shelf lives. So the lens will remain unblemished, perfectly intact as it was designed. Like proud gun collectors, I sit down with my lenses, twice a month, to meticulously clean and polish, with a bottle of Bourbon on hand. Worry not, I don't polish lenses with the Bourbon. I polish that myself while giving the lenses some TLC.


Thank you all for such sage advise on what I could do to use this amazing lens. No way would I damage any lens. Yeah, I could sell it off and get a Super Takumar 35mm f3.5 in M42 mount, which I should have bought in the first place since I am already using a bunch of M42 lenses with the 5d Mk II. But why compromise? Even though the Pentax mirrorless sounds like a great idea, I have decided to pick up a gently used Sony a7r2 mirrorless body tomorrow. I will get a couple of adapters for M42 and K-mount lenses by next week and be done with it. I have a feeling the bokeh and sharpness of these glasses are going to be just as good in 42MP images. Solved!!!

I have a beautiful Spotmatic 1000 camera with screw mount. I will get a K1000 to shoot with this SMC 35mm lens on film as well. Here is a picture of my Spotmatic with the Takumar 200mm lens with 20 aperture blades, clean as a whistle after one of those Bourbon sessions ;-)

I am glad to have joined this Pentax forum. Thanks