Bo-ming Tong of Conurus Imaging Corporation pioneered the Contax to Canon conversion process, thus giving Contax N lenses a new lease on life. Using a Contax C/Y lens, or a Hasselblad, or a Rollei, or even Leica-R lens on the Canon dSLRs is nothing new. Buy the appropriate adapter and you have a manual focus lens with stop down metering. Often these adapters are very low quality and have tolerance issues which lead to problem with infinity focus, uneven sharpness across the frame and/or fringing (CA).

Conurus’ approach is NOT just a simple adapter.  This is a comprehensive electronic conversion resulting in a fully functional Contax auto-focus lens with auto aperture on a Canon EOS body. The Contax-N lens operates just like any other Canon EF lens.  The Contax mount is replaced with high precision Canon mount which mounts very smoothly and securely. No adapters, no need for manual focus, no stop down metering.  Contax fans can now enjoy Carl Zeiss optics on their Canon cameras - without compromise.

THE CONURUS CONTAX TO CANON EF MOUNT CONVERSION

Conurus’ conversion process addresses both hardware and software. The physical mount is changed, custom firmware is loaded into the lens and the electrical contact assembly is replaced. The firmware is upgradable (this is

a “factory” upgrade) which is good news if Canon decides to change their protocols with the 1Ds Mark III and subsequent models. Mount tolerances are carefully measured, and if needed shimmed to ensure proper performance at infinity. Each lens is converted to extremely tight tolerances and all these measurements are documented for each lens on Bo-ming’s website (type in your serial number and can see all the measurements recorded during the conversion process).

Part of the conversion process includes “calibrating” the lens’ auto focus. Bo-ming calibrates the lens by testing it on his Canon 1Ds - a time consuming process in itself. The Contax 85N is my third conversion from Bo-ming, and each lens has focused perfectly on my Canon 1Ds Mark II. Accurate auto-focus was one my big concerns, and this has proven to be a non-issue. If focus adjustment is needed, Bo-ming included a micro focus adjustment feature in the firmware whereby the end-user can adjust the lens to their camera. The process is similar to Canon’s new micro focus adjustment in the 1D Mark II and 1Ds Mark III. Instead of the adjustment being store in the body, it is stored in the lens.

Bo-ming’s craftsmanship and attention to detail is excellent - the 85N came back looking as good as it did before its journey. Mounted on the Canon 1Ds Mark II the 85N feels and acts like any other Canon EF lens on the 1Ds Mark II --- it just happens to read “Contax” on the barrel. One big improvement is that now the aperture can be adjusted in 1/2 or 1/3 stop increments. On a Contax camera the aperture is adjusted in a 1 stop increments via the aperture ring. We are getting MORE functionality with the Contax lenses on a Canon body - amazing!

CONTAX N 85MM F1.4 PLANAR PERFORMANCE AND HANDLING

I know this is the “meat” that most people are looking for, but in 2007 my equipment list underwent massive changes and the 85N had to find a new home. At the end of last year I purchased a Phase One P25 back and the Canon gear is all but a memory (update - purchased a Canon 1Ds Mark III in March 2008 and started the 1Ds3 Blog).

Before uploading the gear to Ebay, I took 50 quick snaps with the 85N to make sure everything worked correctly. Albeit cheesy test shots of the dog, flowers, backyard, etc., the 85N pictures looked really nice. Probably the biggest differences in the Contax 85N and Canon 85L were the colors and contrast. The 85N’s colors are more natural, whereas the Canon 85mm L F1.2 II can produce some hyperactive greens and reds on occasion. The 85N has better contrast in the shadow regions - which is typical of most Contax lenses.

CONTAX 85mm F1.4 N VERSUS CANON 85mm L F1.2 II

Optically the Contax 85N and Canon 85mm F1.2 L II are probably a tie. Maybe one is better here or there, but overall they are both very good lenses. Canon makes very good telephoto lenses, so the question here really is not about sharpness. The differences come down to the coloring and contrast curves. If you like the hyper saturated colors from the Canon lenses, then the Canon 85mm L F1.2 II is the right choice. If you prefer a more natural color palette (though muted compared to a Canon lens) along with better detail in the shadows, then Contax 85N is a good fit. To my eyes the Contax lenses deliver a truer color rendering, and it when it comes to landscapes the Contax lenses are much better.

The 85N’s build quality is more robust than the Canon 85L (I and II). The Canon 85L (I and II) stunk at landscapes; both Canon’s tended to blow out the sky very easily. Taking the same picture with the Canon 24-105L (my review) Canon  70-200mm L F4 IS at the 85mm focal length, the sky would not blow out. I cannot explain this other than guessing there is something unique in how the Canon 85L’s gather light, which may make them troublesome when shooting landscape. Saying the Canon 85L is the wrong tool for a landscape is the easy counterpoint. To that I would counter - then why is the Contax 100/2 Planar a great portrait AND a great landscape lens? I think Canon sacrificed some performance at the expense of the wider apertures to achieve F1.2. For the things I photograph the Canon 85L’s were not a good “tool”, so I would pick a Contax 85N over a Canon 85L.

OVERALL IMPRESSIONS

I only had the Contax 85N for about a month before selling most of the Canon gear in December 2007 to finance a medium format digital back. Now that matters have come full circle (I bought a 1Ds Mark III in March 2008), I wish the Contax 85N were still in the bag. I didn’t have enough time with this lens to form a complete opinion. After buying the lens off of Ebay and paying to have it converted, it cost about the same as buying a Canon 85mm L F1.2 II. Whether or not I pay for more the Contax 85N vs a Canon 85L is a difficult choice. The Contax N 85mm F1.4 is completely different (newer) design than the old manual focus Contax 85mm F1.4 Planar from the 1980’s. Some say the Contax N 85mm F1.4 Planar has been optimized for portrait use. Perhaps so; I have no opinion on this subject.  (Continue to next page)