Does your lens mount conversion service work with all Contax lenses ?

Only autofocus lenses in Contax N mount and medium format lenses in Contax 645 mount are supported.

We do not support and have no plans to support the manual focus Yashica/Contax mount, the rangefinder G mount or the original rangefinder screw mount.

What do you mean by N-mount ?

Contax introduced their last lens mount in 2000, called "N-mount". The N-mount is for 135 format (24mm x 36mm), and features a very wide mount throat, autofocus, and fully electronic communication with no mechanical linkages. There are 3 camera bodies and 9 lenses in the line-up, all discontinued. A chart showing N Series Auto Focus Lens Compatibility is published by Contax UK.

The 9 N-mount lenses are:

lens hoodcasefilter
Vario-Sonnar 2,8/17-35 GB-103NCL-795
Vario-Sonnar 3,5-4,5/24-85 GB-81(incl.)NCL-182
Vario-Sonnar 3,5-5,6/28-80 GB-51(incl.)NCL-655
Vario-Sonnar 3,5-4,5/70-200 GB-77NCL-467
Vario-Sonnar 4-5,6/70-300 GB-75NCL-272
Planar 1,4/50 GB-76NCL-367
Planar 1,4/85 GB-82NCL-882
Makro-Sonnar 2,8/100 GB-73NCL-572
Tele-Apotessar 4/400 (incl.)NCL-946(rear)
Full information about N-mount lenses, including their MTF curves measured from actual production lenses, is published by Zeiss.

How do I tell if I have a N-mount lens ?

Look at the rear end of your lens. A N-mount lens has 10 gold-plated electrical contacts. Also, since the N-mount was introduced in 2000, any lens older than that cannot possibly be N-mount.

Ok, my Contax lens is manual focus, in Yashica/Contax mount. Do you have any plans to introduce a product which supports my lens?

Really, no. Sorry but we do not have any plans at all, even though we recognize that in terms of market size, the manual focus Y/C mount is orders of magnitude larger than the autofocus N-mount. For manual focus Y/C mount lenses you are referred to other vendors such as Bob Shell, Pham Minh Son or Stephen Gandy. (Although I have never tried any of them. I simply don't have any manual focus Contax lenses!)

Can you convert lens X to mount on camera Y ?

We are narrowly focused on one combination (Contax N or 645 lens to Canon body) for the time being. We are not working on anything else.

Can you adapt Nikon F-mount lenses to mount on a Canon camera ?

You will lose autofocus and auto aperture. We do not sell such an adapter but you may get one from

Does your product work with all Canon cameras ?

Either ourselves or our customers have tested with the following EOS models and reported success (Y) or failure (N). We are removing support for D30, D60 and all film camera bodies in 2010.
camera 64585/1.4all others
60D ???
Rebel T2i550D Y
1D mark IV ???
7D Y
Rebel T1i500D Y
5D mark II YY
50D Y
Rebel XSi 450D
1Ds mark III YYY
40D YYY
1D mark III
Digital Rebel XTi 400D YYY
30D Y
5D YY
1D mark II N Y
Digital Rebel XT 350D Y
1Ds mark II YY
20D Y
Kodak DCS Pro SLR/c Y
1D mark II
Digital Rebel 300D YYY
10D Y
1Ds YY
D60 NNN
1D YYY
D30 NNN
1V NNN
Elan 7E 30E NNN
Rebel G 500 NNN
1N NNN
A2E 5 NNN
630 600 NNN
620 NNN
650 NNN
Thanks to all customers who reported your success to us!

I have a camera which is not in the above list. Will you support it ?

It may or may not work. If we do not have the same camera as yours and there is a compatibility issue, we would try our best to fix it but we would ask you to send in your camera. If we don't even have the camera we would not be able to solve any compatibility problem. There is no guarantee that every problem is solvable but we would refund the purchase price minus shipping if it does not work out.

If you are an existing customer and you have access to a camera not on the above list, please kindly try it and report to us if it works.

Do you license any technology from any OEM ?

We and our products are not licensed, approved or endorsed by Canon, Carl Zeiss, Contax, or Kyocera.

Are there any known issues with your product?

All Contax autofocus lensesIn LiveView mode, contast detect AF does not work.
Vario-Sonnar 2,8/17-35The plastic tab protruding from the rear shroud of the lens has to be cut during installation. (The function of that protruding tab is to prevent you from sitting the lens pointing up without the rear lens cap and scratch the rear element.)
There may be an underexpose problem of up to 1 stop.
Vario-Sonnar 3,5-4,5/24-85At the tele end, and the focal length recorded in EXIF is 86mm instead of 85mm.
Vario-Sonnar 3,5-5,6/28-80There may be an underexpose problem of up to 0.5 stop.
Vario-Sonnar 3,5-4,5/70-200-
Vario-Sonnar 4-5,6/70-300Autofocus performance is unsatisfactory above 200mm.
On some camera bodies, it is not possible to use an aperture slower than f/32.
IMPORTANT: if you are buying a used, unconverted 70-300, please specifically test autofocus at 300mm and make sure the AF turns smoothly and optically if it is sharp wide open.
Planar 1,4/50-
Planar 1,4/85The lens is rotated about 5 degrees off center.
The aperture blades occasionally makes a click noise in preview mode, and when the camera turns off.
The focal length recorded in EXIF is 86mm instead of 85mm.
Makro-Sonnar 2,8/100 AF is the slowest and noisiest among all N-mount lenses.
Tele-Apotessar 4/4002x teleconverter will fit, but not detected, if modified before 2010/07. 1.4x works.
645 Vario-Sonnar 4,5/45-90You will not be able to store AF microadjustment values in a converted NAM-1 adapter for both the 45-90 zoom and the 45mm, 55mm and 80mm lenses, because their focal lengths overlap and a converted NAM-1 adapter will only remember one set of adjustment values per focal length.
645 non-Contax lensesNon-electronic lenses such as the Arsat 30/3.5 fisheye and the Hartblei 45/3.5 Super Rotator are not supported. The Canon camera will give an "Err 01" message when the shutter is fired.

From time to time, more issues may be identified and posted on our technical support forum.

My 24-85 displays f/5.0 instead of f/4.5 at the tele end. Is it a problem?

No. You will always be really shooting wide open. The aperture display may be affected, but never the actual aperture.

At the tele end, 85mm for the 24-85, the maximum aperture is exactly halfway between f/4 and f/5.6. Your camera has a custom function which selects whether the aperture is displayed in 1/2 stop steps or 1/3 stop steps. Not a problem if you select the former on your camera body. If you select the custom function to be 1/3 stop steps, should we round up or round down? It just so happens that the camera body rounds down and displays the nearest slower 1/3 stop.

This is all just some rounding taking place. It cannot be overemphazied that the maximum aperture remains the same. Did I say only the display of the maximum aperture is affected?

If this still bothers you, read this discussion thread about the f/5.0 "problem". You may send your lens back to us for a firmware update. Since firmware version 2.12 the camera displays f/4.5 at 85mm.

EXIF says the focal length is 86mm instead of 85mm. Is that a problem?

When a Vario-Sonnar 24-85 is zoomed to 85mm the focal length recorded in EXIF is 86mm instead of 85mm. This is NOT a problem because a Contax N-Digital camera body exhibits the same behaviour. The 1,4/85 Planar records 86mm in EXIF, too.

Are there infinity focusing issues with a converted Contax N mount lens?

No. Like other autofocus lenses, Contax N lenses focus slightly beyond infinity. Refer to our detailed explanation of infinity focus.

Are there mirror clearance problems with a converted Contax N-mount lens?

If the rear element does not protrude beyond the end of the lens mount, it is impossible for the mirror to hit the rear element of the lens. 7 out of the 9 lenses in the N-mount line-up satisfy this criteria.

The 24-85 has a plastic rear shroud which protrudes by a negligible amount, and the Planar 1,4/50 has a rear element that protrudes by 0.4mm. They will still clear the mirrors of 5D and 5D mark II without any mirror intereference issues. However, the Planar 1,4/50 may not physically fit on a Kenko/Tamron 1.4x teleconverter because of this rear-element protrusion.