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03-10-2008, 10:16 PM   #1
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Adapter from Canon FL/FD mount to Pentax?

So my dad gave me his old Canon FT (model right before the auto-focus), and some rather nice lenses....given that it is all completely manual, are there any adapters so that I could play with the lens on my K10D? For instance he has a 50mm F1.8 etc that I'd imagine might give a nice image.

03-10-2008, 11:03 PM   #2
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It is truely a shame that all that vintage canon glass is out there setting on shelves.
But unfortunatly it is pretty much unusable.
the problem is that the distance from the rear lens flange to the film is shorter than any camera currently in production.
In order to use old FD lenses on any modern camera body of any brand you would have to be able to insert the lens deeper into the body than the lens rear flange will allow.
I've done the research, and I believe it's simply impossible.
There are however adapters that will allow the use of vintage pentax lenses on newer canon eos bodys. and some people have had limited success with nikon lenses on pentax bodies, but from my personal experiments I wouldn't reccomend it.
Levi
03-10-2008, 11:56 PM   #3
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QuoteOriginally posted by Levi Quote
the problem is that the distance from the rear lens flange to the film is shorter than any camera currently in production.
Levi
I imagine that you mean further out than any other camera.
At least from my understanding shorter would mean that you could add a shim to bring it to the right distance.

However you probably wouldn't have to, unless the lens sits too close to the mirror where it won't open or close properly.
You'd just loose your close up focus.

If the lens sits too far out then you'd never get infinity.
However if you can adapt a lens to fit your Pentax it might make one wicked Macro lens.
It'll allow you to focus closer than you possibly could on the old film Canon.
It's a little like adding extension tubes

I learned the above when I started to modify some of my Pentax glass to fit my Sigma. It's sensor is about 2mm closer than the Pentax

Edvard_Grieg,
If you can't work it all out look into getting a good quality 1.4x teleconverter that will fit the lens.
Preferably a brand like Sigma or Tameron, where they make more than one mount.
Plus buy the matching model, in a Pentax mount.

If you take these both into a machine shop they'll most likely be able to machine a hair off the bottom of the canon mount, and fit the Pentax fitting.
Or it might even work if you just fit the Canon fitting onto the Pentax TC, however I can't promise that this would work

Good luck, and have fun.
03-11-2008, 12:27 AM   #4
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QuoteOriginally posted by little laker Quote
I imagine that you mean further out than any other camera.
At least from my understanding shorter would mean that you could add a shim to bring it to the right distance.
What he meant is that the registration distance of the FD is much shorter than other mounts, so if you adapt a FD lens on Pentax, for instance, you will not have infinity focus. And it won't add much macro value since the difference is only ~4mm. There is no other system on the market that can functionally adapt a FD lens. However, if your really want to adapt these lenses, you can learn to adjust the infinity focus yourself and do a mount conversion. Professional shop do offer these services at quite a high price, so only use them if you're desperate.

Edit: the new adapter for FD to EF/EOS mount contains an optical element to correct the registration distance. IQ degradation definitely would occur.


Last edited by aegisphan; 03-11-2008 at 12:38 AM.
03-11-2008, 12:33 PM   #5
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Thank you everyone for your replies, it sounds like the chances of making this work aren't real high, would cost a fair amount of money, and would most likely cause image degradation. It sounds like I would be better off investing that same money in similar lenses etc....thoughts?
03-11-2008, 03:14 PM   #6
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I definitely would go with the alternative. If you're into manual focus lenses, I suggest you to check out mflenses.com or manualfocus.org for user's opinions and advices. Optically speaking, the old manual Zeiss, Tamron SP, and Pentax would not be that far off from today lenses.
03-11-2008, 09:30 PM   #7
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Ok, similar question- what about for Yashica/Contax Y/C Mount?
03-11-2008, 10:09 PM   #8
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LOL, since you're so interested in this subject, I'll give you some of my experience:

Note: Pentax has no cross-brand adapter whatsoever due to the mount size and the registration distance.

1. C/Y mount has very similar registration distance as the Pentax's. However, you need to either to do a mount conversion (probably would yield you infinity focus-if not that you can shave off about 0.02mm), or, like me, do a body mount modification (infinity focus would be a little off so adjustment is easy, though depends on lens). I know how to do Planar 50/85 and Distagon 24/35. The Distagon is easier. Or if you have an extra pentax body, you can try to shave off ~0.02mm on the body mount, and no adjustment is needed. Pentax lenses would focus a little beyond infinity.

2. Nikon F mount: I have tried only the Nikkor 35/1.4. Fitting is ok, not too snug, not too loose. Infinity focus is right on (no adjustment-no mod). From reports, pre-AIS has a greater chance to mount than AI and AIS variants.

3. Olympus OM mount: After I modded my K10D for C/Y lenses, OM lenses can be mounted as well. I don't know if you can mount OM lens without mod or not. Infinity focus is a little off, but it's easier to fix than C/Y. You just need a little spacer with thickness of ~0.03-0.04mm. Or if you can deal with focus beyond infinity then no need for fixing.

4. Sigma AF mount: very similar to Pentax. Personally, I've not tried these, but you can buy Sigma lenses on K-mount so there is no point.

5. 4/3 mount: similar shape, so I assume you can mount after the C/Y mod. No infinity focus (useless for me)

6. Minolta Alpha mount: no experience, but will not yield infinity focus. However, I really like the Rokkor 58/1.2. I might try it out later. People did do the mount conversion so it's not completely hopeless.

7. Canon EF/FD mount: no point really...

03-11-2008, 11:30 PM   #9
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QuoteOriginally posted by aegisphan Quote
LOL, since you're so interested in this subject, I'll give you some of my experience:

Note: Pentax has no cross-brand adapter whatsoever due to the mount size and the registration distance.

1. C/Y mount has very similar registration distance as the Pentax's. However, you need to either to do a mount conversion (probably would yield you infinity focus-if not that you can shave off about 0.02mm), or, like me, do a body mount modification (infinity focus would be a little off so adjustment is easy, though depends on lens). I know how to do Planar 50/85 and Distagon 24/35. The Distagon is easier. Or if you have an extra pentax body, you can try to shave off ~0.02mm on the body mount, and no adjustment is needed. Pentax lenses would focus a little beyond infinity.

Thank you very much for all the info, admittedly you definitely lost me after the first sentence and a half....will the lens fit as is? Will it damage anything without any modifications? What will the infinity focus effect? (Completely lost with the Planar and Distagon etc........)

Thanks!
03-12-2008, 01:56 PM   #10
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Sorry about not being clearer. Basically, there are two ways to adapt a C/Y lens to a Pentax body:

1. Lens mount conversion: you change the C/Y mount into a K mount. This would probably give you infinity focus. If it doesn't, you could sand off ~0.02mm off the base of the mount to get the result.

2. Camera mount modification: I've done this on my K10D. Most people have done this report that infinity focus is a little short. You can fix this problem by either a) sand off ~0.02mm the body mount or b) adjust the infinity focus on the lens

I've done the infinity focus adjustment on the Distagon 28 and know how to do it on the Planar 85. Distagon 35 and Planr 50 would be similar. I think the Distagon's adjustment is easier.
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