Very, very good news - it is possible to convert Rokkor and focus to infinity without shaving 5D mirror, may be it is true only for my 5D , anyway just have done the conversion - the lense is jewel. Light falloff on the edges is minimal, sharpness, boke, purple aberations, color - even on f1.2 absolutely working. and Yes infinity on the 5D!
Quick snaps right after convertion, straight out from the cemera no post processing at all f1.2
Dim.ka_ wrote:
You do not need to file rear ring to obtain infinity Although you need to make the rear lense stay in place.
Please explain.
As far as I know (after experience with many copies of this lens), you will not hit infinity until the rear element (and ring, of course) protrudes well beyond the mount. At that point, the 5D mirror will hit the ring. Even filing the ring will (typically) not allow the mirror to clear.
If you are so sure, please post an infinity shot at f1.2 (the above shot is nice, but it is obviously not shot at infinity) and post a photo of the lens, taken from the side, with the lens set to infinity.
It sounds to me like you are getting infinity by stopping down, which is fine if that is how you will use the lens, but it is not true infinity.
makes me feel good about how much I paid for my copy (mine is not "mint" though).
The most "mint" copy I have tried was not the best performer I have tried. Overall, I certainly would not choose one of these lenses due to its looks (and I would certainly not pay hundreds more for a "mint" one).
I just won an ebay auction for an older one of these at $297. I guess its an ok price these days. Its the metal ring one, probably radioactive... Probably I was bidding against one of you guys!
Anyway, now I am really looking forward to doing Paul/cogitech´s OR thing on it Gotta order an M42 now... Any specific m42-eos adapter I should look for? They seem very similar. Surely not an AF-confirmation version...? Fotodiox version probably ok?
Thanks for making this interesting lens available to the EOS system with your wonderfully detailed write-up, Paul. I am a huge fan of the OM Zuiko 50 1.2, so I am really looking forward to this lens....!
Edited by ovredal73 on May 07, 2008 at 01:36 AM GMT
Try to find a flangeless M42 adapter, otherwise you'll have to file the flange off in order to make room for the huge rear element. I just received three chromed-brass ones today and they all have a flange (not stated in the auction, from "kawamall" on e-bay).
Instead of risking the flange problem with most M42-EOS adapters, I opted for the Pentax K - EOS adapter on my Rokkor so the opening is huge for that gigantic rear element.
I'm pretty sure that's aluminum. It'll work fine, and the black colour could be seen as an advantage, but I prefer to work with the chromed-brass ones. Also, there is no flange in the photo, but the adapter may or may not have a flange. Maybe contact the seller and ask if it has a flange or not (state that you do not want a flange).
Honestly, any of them will work fine but the flanged ones just require more work. It might be a good idea to buy 2 of them if this is your first conversion. If you mess one up, at least you'll have a spare.
Dear Leon, I actually have a Pentax K - EOS sitting around, but I am surprised that it is possible to switch between these different adapters...? It could then actually be any of these...?
I had to look up flange on wikipedia to figure out what you mean by that word, but from what I can understand, almost all adapters will have a flange...?
Leon Noel wrote:
Instead of risking the flange problem with most M42-EOS adapters, I opted for the Pentax K - EOS adapter on my Rokkor so the opening is huge for that gigantic rear element.
Good point. I considered other adapters but always tended to have M42 ones laying about
, anyway just have done the conversion - the lense is jewel. Light falloff on the edges is minimal, sharpness, boke, purple aberations, color - even on f1.2 absolutely working. 
and Yes infinity on the 5D!
