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N to Eos adapter is it possible


Active Member
I am an avid use or Contax Zeiss MM lenses for my Eos 1DIIK. I have heard that the 24-85 N series zoom is particularly sharp and flare resistant.

Does anyone know how the back of the lens looks compared to the MM lenses and is there an adapter to use an N series lens with a mount taking an MM lens.

Does the back of the lens protrude further so there is no room for an adapter?


Last time I asked I got a resounding NO - something about the laws of physics ...
I'm in the same boat, Asher: I'd really like to use the N17-35mm on my 1Ds. This is the reply I received from Zoerk when I asked them if it could be done:
1. Contax N lenses need an electronic device for handling their diaphragm. In this case and in case of their big diameter of the lens bayonet (it can not stick inside the EOS camera bayonet mount) the possible adpter ring must be thicker than 3,5mm and infinity focusing is loosing. Fot Contax RTL , Nikon and Leica R lenses we make adapters for EOS cameras.
While not a resounding no, it looks pretty negative. However, there seems to be enough space between the rear element and the wider than necessary N Mount to replace it with a slightly narrower EOS mount. I am in discussion with a local machinist to determine the feasibility of doing this.
> Is there no aperture ring to manually select aperture on the N lenses? > As far as an adapter is concerned what did the zoerk reference to 3.5 > mm thickness refer too and why would we lose infinity focus? What is > the distance between the lens mount and the focal plane?
Posted long after the previous post....this is just for the record: try Conurus, who now provide adaptors which also maintain the electronic diaphragm and af control.
DJ -
I was going to send my extra 24-85 and 70-300 for conversion(I finally sold the 50mm). I thought that EF was for EOS and F was for the old F1 and AE1 line. Are you sure about the conversion not working for current Canon?

Last time I sent Conurus an e-mail it took them a month to send me the price and mailing confirmation so I'm hoping to get "EF" ="EOS" confirmation here rather than wait for them.

I have to eat my words. Please don't ask me to print them on 24x36 SuperGlossy paper first. You are correct - I was thinking of the FD mount. EF is the EOS line's mount.

Dang! Now you have me thinking!
Actually, the conversion is well underway and available.

Conurus has said that he will have conversions available for all Contax 645 lenses and the remaining N-Mount lenses (50mm f1.4, 70-200mm f3.5-4.5, and 28-80mm f3.5-5.6) by this year (2007). The other N-Mount lenses like the 17-35mm f2.8, 24-35mm f3.5-4.5, 70-300mm f4-5.6, 100mm f2.8 Macro, and 85mm f1.4 are now being converted and currently available with EF mount. I have been keeping in touch with the guy and all I can say is he is extremely professional and truly a pleasure to deal with (I am not affiliated with him, but can definitely vouch for the work he does).

If you ever wanted the best of both worlds - amazing high performance digital bodies with high ISO - low noise and the best optics in the world, this conversion paves the way for that. The N-mount lenses hold the reds very well. The micro contrast and true to life "Zeiss look" are now available on Canon's best digital bodies. I was blown away when I saw the first image taken with the converted 24-85mm f3.5-4.5 on the 1Ds and the 5D. The converted lenses work on all EOS EF mount Canon Digital (and film) bodies providing high speed AF (very similar to canon's USM speed almost) and they stop down just like any canon lens - all while providing autofocus/MF. In fact, it's just like using a canon EF USM "L" lens - only better.

I have had my 24-85mm f3.5-4.5 and 70-300mm f4-5.6 converted by conurus. The colors are simply superb - I mean superb. I sold my Canon 24-70mm f2.8, 16-35mm f2.8 L (on sale now), 70-200mm f2.8, and 70-300 DO lens once the conversion was made available. I have recently sent my 17-35mm f2.8 N mount to conurus to get that converted as well. It should be interesting - Canon 5D and 1-series bodies using nothing but Zeiss N-mount glass. I have my remaining N-mount lenses (extra 24-85mm, 70-200mm and N-system up for sale now) except the 50mm f1.4 which I plan to get converted. The Zeiss planar has got to beat or match the Canon 50mm f1.2L for sure.

After the conversion, the aperture ring on the lens is non-functional as EOS bodies use the body to control the aperture. The images - sharp from corner-to-corner, the colors, and the 3D look make up for the cost and everything else. Check out his website as well as the alternate forum on fred Miranda which have a ton of s&les posted.

I had my 24-85mm f3.5-4.5 N-Mount converted because it was smaller (and maybe a bit lighter) than the 24-70mm while being a better performer. When used with my 5D, it gives me a very lightweight body+lens combo for a walk around/travel camera.

I had my 70-300mm f4-5.6 N-mount converted as it gives better results than my 70-200mm f2.8 L and my 28-300mm f3.5-5.6 L while being much lighter and smaller than either lens. In fact it is smaller than the 70-200mm f4L in size. Almost comparable to primes.

With the 17-35mm f2.8 L: Well – not much to say here except this is the only lens to come close to the kind of wide angle primes - the Distagon 21mm f2.8 (which has to be manually focused and uses step down metering with an adapter). Comparison tests and s&les of the converted 17-35mm f2.8 comparing it to the Nikon 17-35mm f2.8 and Canon 16-35mm f2.8 have been posted on the web and the Contax 17-35mm f2.8 beats both of them on the wide end where this lens really shines.

Also, for those of you that have Contax N-mount lenses, it might help to know that the primes are now almost impossible to find and the prices on both primes and zooms have shot up. The most recent sale I checked on had the converted 17-35mm f2.8 go for $2900 and the N-mount (unconverted) zoom go for $2000 - $2300 (if you can find one). The 50mm now sells for $700 (used to be in the $500 range). The 100mm f2.8 macro which sold on the used market for $699 now sells for $1400 (go figure). The 85mm f1.4 now goes for $2300 (whew !!). 24-85mm f3.5-4.5 is selling for $600 - $780. 70-200mm which used to sell for $400 was around $600. So if you have these gems in your bag, having them converted or selling them now should bring in some $$$.

Sorry for the long post, hope this info helps
Thanks Pascal. I guess it's only a matter of time - and cash - before i get my n lenses converted. i am glad to see the price appreciation of the lenses. there was a time that i almost gave up and sold them all (17-35, 24-75, 50, 85, 100, 70-300, 400). Now with the conurus option, i can look forward to a canon body when my ND packs up for good.