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szk71 · 01-24-2008, 09:55 AM

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Seems the various versions of the 50mm f1.2 have different #s of aperture blades. I'd think they would have different optical signitures therefore.

MRRiley · 01-24-2008, 12:04 PM

to the point of the OP's question. You would need a Pentax K-to-Canon adapter. Not sure anyone even makes one, and you'd have to be careful what Canon mount, as there are at least 3 kinds. In your case, you'd most likely have to get PK-to-Canon Digital...

Ohhhh, and regardless of what version (K, A, etc) the 50mm is, it will be all manual and stop-down metering on your canon if you do manage to find an adapter.

p.s. I looked online and couldnt find a PK-to-Canon adapter. Did see a Nikon-to-Canon one for $150 so this exercise could end up costing more than just out and out buying a fast Canon lens for your DSLR.

amateur6 · 01-24-2008, 12:29 PM

Originally posted by MRRiley

to the point of the OP's question. You would need a Pentax K to Canon adapter. Not sure anyone even makes one, and you'd have to be careful what Canon mount, as there are at least 3 kinds. In your case, you'd have to get PK-to-Canon Digital...

Ohhhh, and regardless of what version (K, A, etc) the 50mm is, it will be all manual and stop-down metering on your canon if you do manage to find an adapter.

(sorry, Mike, not stalking you, I swear)

Judging by what was done here (Pentax SMC Pentax 200/2.5 lens - eBay (item 110205030884 end time Dec-12-07 17:59:27 PST)) , it seems that you'll also have to cut off the aperture control lever and aperture lever shield, if this person knew what they were doing...

Peter Zack · 01-24-2008, 12:33 PM

I think you are both right. I saw a similar 77mm Limited that was cut down the same way and the mount adapter he used was similar to the following:

Mount Adaptor for Canon EOS Body to Pentax K Lenses - eBay (item 270102955098 end time Feb-16-08 09:27:37 PST)

It seems like an expensive way to modify a lens as well as the lens might us infinity focus.

MRRiley · 01-24-2008, 12:33 PM

Originally posted by amateur6

(sorry, Mike, not stalking you, I swear)

Judging by what was done here (Pentax SMC Pentax 200/2.5 lens - eBay (item 110205030884 end time Dec-12-07 17:59:27 PST)) , it seems that you'll also have to cut off the aperture control lever and aperture lever shield, if this person knew what they were doing...

I can't get to ebay from work, but that does sound reasonable. The lever and shield would probably impact or interfere with mounting. What an horrible end to a fine Pentax lens... being butchered so it can be mounted on a Canon... UGH!

MRRiley · 01-24-2008, 12:36 PM

Originally posted by Peter Zack

I think you are both right. I saw a similar 77mm Limited that was cut down the same way and the mount adapter he used was similar to the following:

Mount Adaptor for Canon EOS Body to Pentax K Lenses - eBay (item 270102955098 end time Feb-16-08 09:27:37 PST)

It seems like an expensive way to modify a lens as well as the lens might us infinity focus.

Doing this to an old 50mm f1.2 is sad but to do it to a 77mm LTD should be a felony punishable by DEATH!

szk71 · 01-24-2008, 02:11 PM

Oh no... Are you guys trying to talk me out of this

It must be a conspirisy.

I'm using m42 lenses on my canon with no problems. Are you saying there would be issues with the K mount?

I have no problems with using an adapter, but if I must modify the lens... well then it's going to be up for sale here on the forum. Here's the adapter I plan on using.

Canon EOS to Pentax K PK Lens Adapter Brass NEW - eBay (item 360015505272 end time Jan-26-08 17:16:31 PST)

Last edited by szk71; 01-24-2008 at 02:37 PM.

Peter Zack · 01-24-2008, 02:39 PM

Not trying to talk you out of it but a screwmount and a k mount are different animals. You have to cut the flange off and also the aperture lever as well. I've seen a few posts on this. Then the lens is totally manual metering and from what I've read you also will loose infinity focus. Doesn't really make a lot of sense to pay upwards of $200 for a lens adapter that will be questionable on the Canon body.

On top of that the lens becomes worthless as I'd assume there would be very few Canon owners that would want it and Pentax owners wouldn't give you more than $50-100 for it used due to the cost of repairing it back to working condition.

Peter Zack · 01-24-2008, 02:53 PM

This is taken from a Canon board that was discussing the trouble involved.

Unfortunately-as linked above-the pentax K mount models can't be adapted easily.
The problem is are the stop down lever and it's protector which protrude too far back .These don't allow the lens to be mounted back far enough to achieve infinity focus.
Apart from this there are no reasons they can't be used ,so if you have a particular favorite lens it would be possible to adapt it to EOS-you'd just have to remove the aformentioned parts and get a new mount plate machined up.Modifying one off an EF lens would probably be easier.

szk71 · 01-24-2008, 03:18 PM

I guess I should have read up on this before I made the purchase. I have no problems modifying a cheap lens, but not an f1.2 Guess it'll be up for sale.

Shucks, I would have loved to try it out on digital.

amateur6 · 01-24-2008, 03:26 PM

Originally posted by szk71

I have no problems modifying a cheap lens, but not an f1.2 Guess it'll be up for sale.

WOO-HOO!

*ahem* I mean, aw, that's a shame. Seriously, sorry.

...wait, I know -- just put the canon up for sale instead!

Finn · 01-24-2008, 04:17 PM

Originally posted by szk71

I guess I should have read up on this before I made the purchase. I have no problems modifying a cheap lens, but not an f1.2 Guess it'll be up for sale.

Shucks, I would have loved to try it out on digital.

Hey, that's easy! Buy a Pentax!

Barbecueboy · 01-29-2008, 05:40 PM

Originally posted by Sprags

I'll trade the Nikon FM2 I have for an MX.
That was my favorite camera I had in the 80's.

I actually sold my nikon FE to buy my black (second) MX.
It makes sense with the wealth of K-mount lenses I have..

falconeye · 02-06-2008, 07:10 PM

Originally posted by MRRiley

I can't get to ebay from work

Since you are posting, though: if Google works for you, you may always access sites as follows:

Translated version of http://www.ebay.com/

:ugh:

jslifoaw · 02-06-2008, 07:29 PM

If I recall correctly, the aperture lever only needs to get shortened for FF Canons. The mirror on others is small enough that it won't hit the lever when the shutter is fired.

I could be wrong, but this is what I heard. Otherwise I might have a 5D by now! (But no way in hell would I mangle my Pentax stuff just for FF)

01-24-2008, 12:04 PM	#17
MRRiley Veteran Member Join Date: Feb 2007 Location: Sterling, VA, USA Photos: Gallery \| Albums Posts: 6,275	to the point of the OP's question. You would need a Pentax K-to-Canon adapter. Not sure anyone even makes one, and you'd have to be careful what Canon mount, as there are at least 3 kinds. In your case, you'd most likely have to get PK-to-Canon Digital... Ohhhh, and regardless of what version (K, A, etc) the 50mm is, it will be all manual and stop-down metering on your canon if you do manage to find an adapter. p.s. I looked online and couldnt find a PK-to-Canon adapter. Did see a Nikon-to-Canon one for $150 so this exercise could end up costing more than just out and out buying a fast Canon lens for your DSLR. Last edited by MRRiley; 01-24-2008 at 12:30 PM.

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01-24-2008, 09:55 AM	#16
szk71 Junior Member Join Date: Dec 2007 Location: Canada Posts: 46 Original Poster	Staff note: This post may contain affiliate links, which means Pentax Forums may earn a small commission if a visitor clicks through and makes a purchase. If you would like to support the forum directly, you may also make a donation here. Seems the various versions of the 50mm f1.2 have different #s of aperture blades. I'd think they would have different optical signitures therefore.

01-24-2008, 12:29 PM	#18
amateur6 Senior Member Join Date: Mar 2007 Location: Rhode Island Photos: Gallery Posts: 177	Originally posted by MRRiley to the point of the OP's question. You would need a Pentax K to Canon adapter. Not sure anyone even makes one, and you'd have to be careful what Canon mount, as there are at least 3 kinds. In your case, you'd have to get PK-to-Canon Digital... Ohhhh, and regardless of what version (K, A, etc) the 50mm is, it will be all manual and stop-down metering on your canon if you do manage to find an adapter. (sorry, Mike, not stalking you, I swear) Judging by what was done here (Pentax SMC Pentax 200/2.5 lens - eBay (item 110205030884 end time Dec-12-07 17:59:27 PST)) , it seems that you'll also have to cut off the aperture control lever and aperture lever shield, if this person knew what they were doing...

01-24-2008, 12:33 PM	#19
Peter Zack Pentaxian Moderator Emeritus Join Date: May 2007 Location: Edmonton Alberta, Canada Photos: Gallery \| Albums Posts: 10,643	I think you are both right. I saw a similar 77mm Limited that was cut down the same way and the mount adapter he used was similar to the following: Mount Adaptor for Canon EOS Body to Pentax K Lenses - eBay (item 270102955098 end time Feb-16-08 09:27:37 PST) It seems like an expensive way to modify a lens as well as the lens might us infinity focus.

01-24-2008, 12:33 PM	#20
MRRiley Veteran Member Join Date: Feb 2007 Location: Sterling, VA, USA Photos: Gallery \| Albums Posts: 6,275	Originally posted by amateur6 (sorry, Mike, not stalking you, I swear) Judging by what was done here (Pentax SMC Pentax 200/2.5 lens - eBay (item 110205030884 end time Dec-12-07 17:59:27 PST)) , it seems that you'll also have to cut off the aperture control lever and aperture lever shield, if this person knew what they were doing... I can't get to ebay from work, but that does sound reasonable. The lever and shield would probably impact or interfere with mounting. What an horrible end to a fine Pentax lens... being butchered so it can be mounted on a Canon... UGH!

01-24-2008, 12:36 PM	#21
MRRiley Veteran Member Join Date: Feb 2007 Location: Sterling, VA, USA Photos: Gallery \| Albums Posts: 6,275	Originally posted by Peter Zack I think you are both right. I saw a similar 77mm Limited that was cut down the same way and the mount adapter he used was similar to the following: Mount Adaptor for Canon EOS Body to Pentax K Lenses - eBay (item 270102955098 end time Feb-16-08 09:27:37 PST) It seems like an expensive way to modify a lens as well as the lens might us infinity focus. Doing this to an old 50mm f1.2 is sad but to do it to a 77mm LTD should be a felony punishable by DEATH!

01-24-2008, 02:11 PM	#22
szk71 Junior Member Join Date: Dec 2007 Location: Canada Posts: 46 Original Poster	Oh no... Are you guys trying to talk me out of this It must be a conspirisy. I'm using m42 lenses on my canon with no problems. Are you saying there would be issues with the K mount? I have no problems with using an adapter, but if I must modify the lens... well then it's going to be up for sale here on the forum. Here's the adapter I plan on using. Canon EOS to Pentax K PK Lens Adapter Brass NEW - eBay (item 360015505272 end time Jan-26-08 17:16:31 PST) Last edited by szk71; 01-24-2008 at 02:37 PM.

01-24-2008, 02:39 PM	#23
Peter Zack Pentaxian Moderator Emeritus Join Date: May 2007 Location: Edmonton Alberta, Canada Photos: Gallery \| Albums Posts: 10,643	Not trying to talk you out of it but a screwmount and a k mount are different animals. You have to cut the flange off and also the aperture lever as well. I've seen a few posts on this. Then the lens is totally manual metering and from what I've read you also will loose infinity focus. Doesn't really make a lot of sense to pay upwards of $200 for a lens adapter that will be questionable on the Canon body. On top of that the lens becomes worthless as I'd assume there would be very few Canon owners that would want it and Pentax owners wouldn't give you more than $50-100 for it used due to the cost of repairing it back to working condition.

01-24-2008, 02:53 PM	#24
Peter Zack Pentaxian Moderator Emeritus Join Date: May 2007 Location: Edmonton Alberta, Canada Photos: Gallery \| Albums Posts: 10,643	This is taken from a Canon board that was discussing the trouble involved. Unfortunately-as linked above-the pentax K mount models can't be adapted easily. The problem is are the stop down lever and it's protector which protrude too far back .These don't allow the lens to be mounted back far enough to achieve infinity focus. Apart from this there are no reasons they can't be used ,so if you have a particular favorite lens it would be possible to adapt it to EOS-you'd just have to remove the aformentioned parts and get a new mount plate machined up.Modifying one off an EF lens would probably be easier.

01-24-2008, 03:18 PM	#25
szk71 Junior Member Join Date: Dec 2007 Location: Canada Posts: 46 Original Poster	I guess I should have read up on this before I made the purchase. I have no problems modifying a cheap lens, but not an f1.2 Guess it'll be up for sale. Shucks, I would have loved to try it out on digital.

01-24-2008, 03:26 PM	#26
amateur6 Senior Member Join Date: Mar 2007 Location: Rhode Island Photos: Gallery Posts: 177	Originally posted by szk71 I have no problems modifying a cheap lens, but not an f1.2 Guess it'll be up for sale. WOO-HOO! ahem I mean, aw, that's a shame. Seriously, sorry. ...wait, I know -- just put the canon up for sale instead!

01-24-2008, 04:17 PM	#27
Finn Veteran Member Join Date: Feb 2007 Location: Phoenix Photos: Gallery Posts: 1,056	Originally posted by szk71 I guess I should have read up on this before I made the purchase. I have no problems modifying a cheap lens, but not an f1.2 Guess it'll be up for sale. Shucks, I would have loved to try it out on digital. Hey, that's easy! Buy a Pentax!

01-29-2008, 05:40 PM	#28
Barbecueboy New Member Join Date: Nov 2007 Location: Rotterdam Posts: 22	Originally posted by Sprags I'll trade the Nikon FM2 I have for an MX. That was my favorite camera I had in the 80's. I actually sold my nikon FE to buy my black (second) MX. It makes sense with the wealth of K-mount lenses I have..

02-06-2008, 07:10 PM	#29
falconeye Veteran Member Join Date: Jan 2008 Location: Munich, Alps, Germany Photos: Gallery Posts: 6,871	Originally posted by MRRiley I can't get to ebay from work Since you are posting, though: if Google works for you, you may always access sites as follows: Translated version of http://www.ebay.com/ :ugh:

02-06-2008, 07:29 PM	#30
jslifoaw Pentaxian Join Date: Apr 2007 Location: Toronto/Victoria Posts: 460	If I recall correctly, the aperture lever only needs to get shortened for FF Canons. The mirror on others is small enough that it won't hit the lever when the shutter is fired. I could be wrong, but this is what I heard. Otherwise I might have a 5D by now! (But no way in hell would I mangle my Pentax stuff just for FF)

Pentax MX - which mount is it?

Win a Pentax Limited Lens: Raffle Now Live!