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04-16-2007, 01:00 PM   #1
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Lens mount converters? Anybody know of...

...any way to use the older Canon "FD" mount lenses on either Pentax or on any other digital bodies?
I keep seeing converters to use screwmount lenses on almost everyone else, and even for a Pentax bayonet mount onto other brands. But never for a way for me to use my old FD's on anything else newer. And I have several really nice FD's... *pouting* in Ohio here...
And how about for Nikon's bayonet to Pentax? Anything? I still have several of those as well...
Cheers and thanks in advance for any info gleaned!

Cowboy

04-16-2007, 01:22 PM   #2
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Most mounts are not adaptable to other mounts. The only reason you can get an adapter to put screw mount lenses on Canon mounts is because the screw mount is so much smaller than the current Canon mount. In order for the lens to focus correctly to the film plane (sensor plane) the lens' mount must fit all the way into the camera's mount. Not possible with most combinations.
04-16-2007, 01:27 PM   #3
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Ok... - you're probably going to shudder in revulsion, - but I had a K10D for a week here for evaluation, - and I sort of "gently coaxed" my 50mm 1.4 Nikon AF lens into position onto the K10 and then used the aperture ring and the body's shutter-speed to take a few snaps in the house of my Mom and Gf. Hey, - it worked and the pics were pretty decent.
So I was just wondering whether there might be some other way... I have seen those other mount converters incl. the Pentax bayonet to either Canon or maybe Oly 3/4ths?
Anyone else?

Cheers!
04-16-2007, 01:32 PM   #4
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I just searched the net for this very answer and couldn't find a definitive one.
I'm anxious to see if this is possible as I have a zoom and a wide angle lens from my Canon that I would love to be able to use on my K100.

04-16-2007, 03:17 PM   #5
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k mount is really small and while canon mount is the largest of the mount at present.

These canon lenses either EF or FD would be too large to fit onto pentax camera. FD quality is not that great even when it is mounted onto a canon SLR with adaptor itself - I would pass on FD lenses.

I am not too sure with Nikon lenses but what I do know is that pentax mount cameras have the smallest lens mount. Hence no lenses of other camera companies would be able to be converted to pentax cameras.

Otherwise I have 9 canon L primes to use on k10d then...
04-16-2007, 04:04 PM   #6
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And add to that one of the longest register distances. It is very unfortunate in my opinion, and one of the main reasons to try a Canon. - regards,
04-16-2007, 04:23 PM   #7
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QuoteOriginally posted by davemdsn Quote
Most mounts are not adaptable to other mounts. The only reason you can get an adapter to put screw mount lenses on Canon mounts is because the screw mount is so much smaller than the current Canon mount. In order for the lens to focus correctly to the film plane (sensor plane) the lens' mount must fit all the way into the camera's mount. Not possible with most combinations.
Not really, although that is mostly true in the 35mm realm. The real determining factor is the distance from the back of the lens to the film/sensor - called the register distance. You can always use a lens (in theory anyway) if the register distance for the lens is greater than or equal to the register distance for the camera.
In your case, the Canon FD mount has a register distance of 42mm while the Pentax mount is 45.5mm - meaning that without modifying the lens, it won't focus all the way to infinity.
Another concern with lenses is what to do with all the 'junk' that comes with bayonet/breech mounts. If you do like I do, you can remove the original mount and replace it with a donor K mount, and then you won't have to worry about it. I successfully did this with two Nikon lenses (46.5mm register distance) and you could do it with Olympus OM (46mm) and Leica R (47mm) lenses, too.

The Canon EOS mount (44mm) is short enough that there are adapters for all of the above mounts that don't require you to replace the lens mount. Olympus' 4/3 mount is shorter still, and there are adapters for all those different mounts as well. (I don't think I've seen a Canon FD converter, though.)

And one more thing - medium format lenses have vastly longer register distances, and all of them can be adapted to fit the Pentax K mount. You might have to fashion your own adapter, though. And they'd be really big, and probably not any better than a comparable 35mm lens!

And lastly, I posted on dpreview a long time ago about using Nikon lenses on the Pentax K mount without removing or adapting the lens. It is sometimes precarious, but the entirety of the Nikon F mount fits flush within the K mount.
04-16-2007, 04:31 PM   #8
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Macro?

Probably not really relevant but using other systems macro gear is relatively easy. I use Olympus OM macro lenses, telescoping extension tube and bellows on my *istD. You can easily build an adapter from an extension tube or rear converter. Stop down metering but that's ok for static objects.

cheers

Greg

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