Using autofocus

For Vario-Sonnar 28-80/3.5-5.6 and Vario-Sonnar 70-200/3.5-4.5 ONLY

There is an AF/MF switch on the lens which puts the lens in either autofocus or manual focus mode. Put the lens in manual focus mode first before rotating the focusing ring.

For all other lenses EXCEPT Vario-Sonnar 28-80/3.5-5.6 or Vario-Sonnar 70-200/3.5-4.5

For all other lenses, there are no AF/MF switches. Set the aperture ring of the lens to minimum aperture (f/16, f/22 or f/32 depending on lens) for manual focus operation.
setting the lens to manual focus

Set the aperture ring to any other position to put the lens in autofocus mode.

setting the lens to autofocus

Your lens supports full-time manual focus. You may rotate the focusing ring at any time to adjust focus, even in autofocus mode.

How good is the AF speed?

AF speed matches or exceeds that on a Contax N camera body, but lags behind similar Canon lenses. Due to slower AF compared to Canon you may not be able to reach 10fps, 8fps, 6.5fps or 5fps in AI SERVO mode.

How good is the AF accuracy?

We took thousands of test target shots to offer you the best autofocus accuracy in the industry. See this discussion thread for an example of the Planar 85mm f/1.4 wide open.

For a f/2.8 or slower lens, you could expect it to work right out of the box accurately without any adjustments. For a fast f/1.4 lens, individual variations between camera bodies become important and it may be necessary to use the AF micro-adjustment feature to match the lens to your camera body. We built the AF micro-adjustment feature into every converted lens. You may use the one built into the lens or your camera body, or both.

Our in-lens AF microadjustment is the most flexible of its kind, being the only means available on the market to individually adjust different focal lengths of a zoom lens, and to individually adjust infinity, medium focusing distances and closest focusing distance.

You may enter the lens' serial number or tracking number to check the firmware version of the lens. If it is newer than or equal to version 3.13 (2010/08/22 or later) it is up-to-date. If it is older than 3.00, a firmware update to the latest version may improve the lens' AF accuracy. You may send it back to us for a firmware update for a nominal shipping charge.

Please enter the serial number or post-office tracking number of your lens:


If your lens stops working, please follow these troubleshooting procedures.

Make sure the lens is not set to manual focus mode

Make sure the aperture ring of the lens (NOT the camera body) is not set to minimum aperture (f/16, f/22 or f/32 depending on lens), if your lens does not have an AF/MF switch. Make sure the AF/MF switch, if your lens has one, is set to AF.

Is depth-of-field preview working?

If depressing the dept-of-field preview button of your camera body has no effect, and your camera body displays an aperture value of 00 or some fixed value that cannot be changed even in Av mode (e.g. f/4.0, f/8.0, f/9.0 or f/13), your camera body is not communicating with the Conurus protocol translation circuitry properly. Wipe the electrical contacts of your camera body and your lens clean and try again. Contact us if after cleaning, depth-of-field preview still does not work and the camera body still does not display aperture properly.

Has the lens been unused in storage for an extended period of time?

Vario-Sonnar 17-35, Vario-Sonnar 24-85, Vario-Sonnar 70-300 and Planar 50/1.4 are equipped with ultrasonic motors which may stop functioning if left unused for an extended period of time. Try this procedure:

Manually focus to infinity, and continue to turn past infinity for one turn.

Manually focus to minimum focusing distance (0.5m for 24-85 and 17-35, 0.45m for 50/1.4, 1.5m for 70-300), and continue to turn beyond minimum focusing distance for one turn.

Note: an autofocus malfunction is always a hardware issue. A firmware upgrade will NOT be able to fix the problem.

How quiet/noisy are the lenses ?

Of course, a lens mount conversion does not make the lens any more or any less noisy. The following table is my subjective rating of several Contax lenses. Roughly, "quiet" is equivalent to the noise level of a typical Canon micro-USM lens.

Quiet Vario-Sonnar 24-85
Vario-Sonnar 70-300
Pretty good Vario-Sonnar 17-35
Planar 1,4/50
Moderate Planar 1,4/85
Tele-Apotessar 4/400
Vario-Sonnar 28-80
Vario-Sonnar 70-200
Noisy Makro-Sonnar 2,8/100

Apo-Makro-Planar 120/4 on NAM-1

Apo-Makro-Planar 120/4 is a manual focus lens. If the aperture ring of the lens is set anywhere between f/4 and f/32, the "focus trap" feature is turned on. The shutter will not trip unless the autofocus sensor of the camera body detects that something is in focus. You may fully depress the shutter and turn the manual focus ring. The shutter will trip as soon as the subject is in focus. To turn off the focus trap feature temporarily, set the aperture ring of the lens to f/45. To turn it off permanently, refer to the additional instructions on our technical support forum.