REVIEWS - Accessories - Leitax Adapter for Contax RTS Lenses to Canon EF

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Leitax Contax RTS to Canon-EF Mount Lens Adapter


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Leitax Adapter

Satin Finish

Leitax Adapter

Focus Confirmation Chip

Leitax Adapter

Contax Kit

Leitax Adapter

Sits Atop Existing Mount

Leitax Adapter

Precise Machining and Finish

Leitax Adapter

Easy Access to the Screw Holes

Leitax Adapter

Narrow Mount on Contax 35-135mm


For many years I used the "HappyPageHK" adapters purchased from Ebay, but I eventually decided to stop using adapters with the locking pin / tab because it is a single point failure for locking the lens to the adapter. Leitax’s adapters use 4 to 10 screws (depends on the lens) to secure the adapter to the lens. My first Leitax adapter was for a Leica 50mm Summilux-R (Leitax review here). It was a very positive experience, so I felt comfortable ordering the Leitax narrow and wide mount Contax / Canon adapters for the Contax 100mm F2 Planar and Contax 35-135mm F3.4-4.5 Sonnar Vario. With the Dandelion focus confirmation chips pre-installed on each adapter, the cost per adapter was ~$135 including shipping to the US (this was around 2010).


The Leitax adapter is one piece, so it is solid with no flex or play. It sits atop the Contax mount and re-uses the same screw holes. Installation requires 2-3 minutes and is 100% reversible. To install the adapter, simply remove the Contax screws, place the Leitax adapter on top, line it up and then screw it in place with the new screws included with the adapter. The end result is a mount that feels solid with no shifting or rotation. There are no flanges that need spreading to ensure a tight fit between the adapter and lens because the lens is SCREWED to the adapter. Likewise, the fit on the Canon 1Ds Mark III is perfect. It mounts as smoothly as a Canon lens, and when locked in place, there is minimal rotational play.

The adapter’s fit and finish is equally good. The adapter is cupped and its sides slip over the original Contax bayonet. The metal appears to be nice quality with a satin finish. The Dandelion chip installation on the adapter itself looks pristine - especially compared to some of the other adapters I have seen with dried glue oozing from the edges. The adapter’s thickness measures 1.43mm to 1.44mm. It was difficult to get a good measurement, so there is some margin of error. Both the 100mm Planar and 35-135mm Sonnar Vario focus to infinity on the 1Ds Mark III.

There are are two types of Leitax Contax / Canon adapters - “wide” and “narrow”. To figure which adapter(s) you need, it is best to email David at Leitax. The price is the same for either type.


Programming the Dandelion chip is “different”. Reading the instructions is well worth the time (available here). To enter set-up mode, the shutter has to be fired; however, in the chip’s default settings that is tricky with the 1Ds Mark III. Before starting the programming process, the 1Ds Mark III needs to be in Servo Focus mode. Once in Servo Mode, then the adapted lens can be mounted and the shutter fired to enter the set-up mode. Once in set-up mode, the first thing I set is allowing the adapter to shoot in manual focus mode. This is a critical first step for 1-Series owners.


The Leitax adapter’s build quality is the best I have seen. I have owned four Leitax adapters and have not noticed any quality variance. My only gripe is the Dandelion chip; I wish Leitax would offer the Optix V5 chip as well - simply because that chip is easier to program. I cannot get too fussed over the Dandelion chip because once it is set-up, I do not have to mess with it again (unless re-using the adapter on a different lens). Before writing this review, I used the Leitax Contax adapters for a year and they have been trouble-free. If you are in the market for a high quality Contax adapter, be sure to check out

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