THE FF, 5D, 1.3x AND 1.6x COLUMN HEADINGS

The Contax C/Y / Canon database is a quick reference to see which Contax RTS lenses can be mounted on Canon dSLRs via third party adapters. Most lenses work without issue; however, some lenses extend too far into the chamber and the Canon mirror will not clear the rear element or some other portion of the lens assembly. Most people will only need the FF, 5D, 1.3x and 1.6 columns. Scrolling to the right provides more information about the lenses.

FF refers to Canon’s professional full-frame dSLRs such as the Canon 1Ds, 1Ds Mark II, 1Ds Mark III and 1Dx.

refers to Canon’s professional full-frame dSLRs such as the Canon 1Ds, 1Ds Mark II, 1Ds Mark III and 1Dx. 5D refers to the Canon 5D, Mark II, Mark III and Canon 6D. The Canon 5D / 6D series have their own column because the 5D’s mirror clearance is different than the Canon 1-Series.

refers to the Canon 5D, Mark II, Mark III and Canon 6D. The Canon 5D / 6D series have their own column because the 5D’s mirror clearance is different than the Canon 1-Series. 1.3x refers to the Canon APS-H bodies with a 1.25x or 1.3x crop factor. This includes the Canon 1D family which consists of the 1D, 1D Mark II, 1D Mark IIn, 1D Mark III and 1D Mark VI.

refers to the Canon APS-H bodies with a 1.25x or 1.3x crop factor. This includes the Canon 1D family which consists of the 1D, 1D Mark II, 1D Mark IIn, 1D Mark III and 1D Mark VI. 1.6x refers to the APS-C bodies, including the EF mount dSLRs (D30, D60 and 10D) and EF-S bodies (20D, 20Da, 30D, 40D, 50D, 70D, 7D, 300D, 350D / XT, 400D / XTi, 450D / XSi, 500D / T1i and 550D / T2i).

WHAT DO “M”, “S” AND “I” MEAN?

Y means “YES”. “Yes” means the Contax lens will work on the respective Canon dSLR and most people have not experienced any issues.

means “YES”. “Yes” means the Contax lens will work on the respective Canon dSLR and most people have not experienced any issues. N means “NO”. In some case the lens or camera can be modified to accommodate some of the marginal lenses. For lens-camera combinations marked “N”, there is not a realistic solution.

means “NO”. In some case the lens or camera can be modified to accommodate some of the marginal lenses. For lens-camera combinations marked “N”, there is not a realistic solution. I means “Iffy”. A lens earns an “Iffy” rating if some people say a given lens and Canon combination work while other people say the combination did not work. Since there is no clear consensus, “Iffy” was added.

means “Iffy”. A lens earns an “Iffy” rating if some people say a given lens and Canon combination work while other people say the combination did not work. Since there is no clear consensus, “Iffy” was added. ? means no data available.

means no data available. Dashes (“-”) mean the data is unavailable.

WHY IS THE CANON 5D LISTED IN ITS OWN COLUMN?

Canon 5D and 5D Mark II owners have reported various adapter and lens combinations catching on the mirror. If a lens mounts and performs correctly on the Canon 1-Series family, unfortunately that does not guarantee the lens-adapter combination will operate correctly on the Canon 5D family. Complicating matters, there are variances amongst Canon 5D’s. For Contax lenses the Canon 5D’s variances in the mirror box have proven troublesome. Unfortunately, this is an issue for Contax lenses more so than Leica R lenses. Probably because the flange thickness on a Canon / Leica R is about 3mm versus ~1.425mm for Canon / Contax adapter.

WHAT ABOUT EF-S MOUNT CAMERAS SUCH AS THE CANON 7D AND 70D?

Canon dSLRs with the EF-S mount such as the Canon Digital Rebels, 20D, 20Da, 30D, 40D, 50D, 60D and 7D work fine. The EF-s cameras have smaller mirrors, so just about any lens will work them.

WHAT ABOUT THE CANON 1 SERIES FAMILY?

Initial reports indicate it is best to consider the 1D family (Mark I, II, III and IV) as having the same clearance as the 1Ds family. According to marketing literature the Canon 1D Mark III sports a new, larger viewfinder. User feedback indicates it is best to consider the 1D Mark III as having the same clearance as a 1Ds and 1Ds Mark II. As of December 2010 the Canon 1D Mark III has proven to be pretty much trouble free. If a lens is marked as “YES” in the 1.25x and FF columns, then it will probably work on the Canon 1D Mark III.

THE DATABASE SHOWS “YES”, BUT I KNOW THE LENS DOESN’T FIT!!!

Deciding whether a lens deserves a “YES” can be tricky because one reader may report “Yes” and another person says it will not work. Most likely the problem is not the lens or the camera body, but the adapter. To address these conflicting reports the “I” category was added, meaning “iffy” - as in the lens may or may not work. Detailed comments are provided below (scroll down).

CONTAX AE MOUNT VS MM MOUNT

The original Contax mounts were called “AE” mounts, later Contax updated the mount to “MM”. The new MM mount offered more exposure / metering options than the original AE. The mechanical differences between AE and MM are moot since the Canon dSLRs do not activate the aperture mechanism. In terms of resale value, whether a lens is AE or MM may make a difference in its price. In some cases the German made AE versions are worth more than the later made MM Japan versions. And there are some German made MM’s which are quite rare, so those lenses tend to fetch a premium. Generally the original AE’s were made in West Germany and the later MM’s were made in Japan. This is not true 100% of the time, but it is a relatively safe generalization.

On MM lenses the smallest aperture number on the aperture ring is marked green instead of white. Supposedly there are some exceptions, but I have not seen any such lenses. A common internet myth is MM lenses have silver mount and original AE’s had a black mount. This is not always true. Some MM’s have a tab on the outer diameter. This tab is not a constant from lens to lens, so it is not the best distinguishing characteristic. Some MM lenses have a small pin along the outer edge of the mount.

Some AE lenses were updated (minor redesigns) when Contax changed from the AE to the MM mount. As an example, the rear mount on the 18mm Distagon changed. Almost all the PDF guides on the Zeiss site are MM, not the AE’s. Alot of web sites mix the AE and MM data, so there tend to be discrepancies in weight. Fortunately the Zeiss pdf’s set the record straight for the MM versions, but the AE versions still hold some mysteries due to conflicting data published on the internet.

In some cases the MM and AE variants are split out in the database. This is intentional because there were some deltas in the lens weight of the AE version compared to the MM version. We have no way of knowing what else changed because the number of elements and groups remained constant. However, Zeiss (Contax) could have changed the design of an element, the composition of an element, lens coatings, sub-assemblies, etc.

SPECIFIC COMMENTS FOR VARIOUS CONTAX LENSES

Before delving into some of these more troublesome lenses, here is some historical data to consider. From 2005-2009 these the Leica R and Contax C/Y pages had equal amounts of traffic; the Contax pages had a slight lead. Then Zeiss started releasing the ZE / ZF lenses around 2010. As of 2016, the Leica pages get 3X more traffic and the Contax page traffic has plummeted. The Zeiss ZE and ZF lenses have effectively killed Contax interest. Just take a look at the Facebook likes - the score is ~200 for Leica vs ~70 for Contax. It is not exactly difficult to figure out why. The new Zeiss ZE's and ZF's offer full EXIF, full auto exposure, generally full support for lens corrections in all major raw file editors (i.e. Lightroom, et al), no fussing with adapters, there's the Zeiss warranty, and you can buy the lenses at B&H, give them a try and return them if you don't like them. And now Zeiss has gone and done one better - updating the ZE's and ZF's to Milvus'. Food for thought.

Canon 5D dSLR and Canon 5D Mark II

The following applies to just about every Contax C/Y lens 50mm and wider

It is very common to read about one Canon user enjoying success with a given lens and adapter combination, and then reading another stating the opposite. There is speculation about Canon’s quality control and the placement of the mirror box. Photographers with multiple Canon 5D’s have cited occurrences where a Contax lens and adapter works fine with one of their 5D’s, but not the other. Finding the right adapter thickness is often the key. For those planning to use Contax lenses as their primary lenses, you may want to consider purchasing a Canon 1Ds, Mark II or Mark III.

Contax 15mm F3.5 Distagon

The following applies to the Canon 5D and 5D Mark II

User reports indicate mirror clearance on the Canon 5D Mark II is still a potential problem. This is not a very common lens, so there is not much information available. Some people are using the lens via Live View, but it is a serious kludge because of the mirror clearance issues.

Contax 18mm F4 Distagon

The following applies to the Canon 5D and 5D Mark II

In some cases a rear retaining ring holding the rear element in place catches the Canon 5D mirror. A thicker adapter resolves problem, but at the risk of losing infinity focus. The problem has been reported with both AE and MM versions. The lens is reported to work fine with the Canon 1-Series bodies and the 1.6x EF-s bodies.

Contax 21mm F2.8 Distagon

The following applies to the Canon 5D and 5D Mark II and possibly others

The generally accepted correct “technical” adapter flange thickness is 1.5mm. In practice 1.425mm has proven to be the best all around adapter thickness. Some have reported 1.2 to 1.3mm being better for the 21mm Distagon. Such a thin adapter could have clearance issues on a Canon 5D - and possibly even the 1-series. Overall, using the 21mm Distagon on a Canon 1.6x or Canon 1-Series will work fine. 5D owners may need to experiment with various adapter thicknesses. My $.02 - save yourself the headaches and get a Zeiss 21mm F2.8 Distagon ZE.

Contax 28mm F2.0 Distagon

The following applies to the Canon 5D and 5D Mark II

Similar to the 18mm Distagon, in some cases a rear retaining ring holding the rear element in place will catch on the 5D’s mirror. A thicker adapter may resolve the problem, but may also compromise infinity focus and could diminish the lens' overall performance given its floating element design. The problem has been reported with both AE and MM versions. The lens is reported to work fine with the 1.6x dSLRs such as 40D and 1-Series bodies. Again, a Zeiss 28mm F2 Distagon ZE is the prudent decision, especially with the Canon 5D bodies. And if money is no object, there is always the Zeiss Otus 28mm f/1.4 ZE.

Contax 28mm F2.8 Distagon

The following applies to the Canon 5D and 5D Mark II

The 28mm F2.8 Distagon has a reputation for not fitting Canon 5D’s. It is the same old story - adapter thickness. The standard procedure is to buy multiple adapters and hope for a magic combination, and/or to try multiple versions of the lens itself.

Contax 35mm F1.4 Distagon

The following applies to the Canon 5D and 5D Mark II

Generally the 35mm F1.4 is not an issue for Canon 5D owners, but some owners have run into problems. Whether the issue was (is) the particular 5D body or adapter is unknown. The 35mm F1.4 does have a floating element design for improved near focus performance, so 35mm 1.4’s can be compromised with with too thick or too thin of adapter. There is also a risk of the mirror striking the rear element if the adapter is too thin. Since 35mm F1.4’s can be impaired by a “cheap” adapter, start with one of the higher grade adapters from Novoflex or Leitax. The Zeiss 35mm F1.4 Distagon ZE is available new and generally a more economical choice. I am not particular fan of the Contax 35mm F1.4 Distagon, so I would opt for the new ZE and enjoy the improved design, auto exposure, full EXIF and not having to mess with adapters (hint hint hint!)

Contax 35mm F2.8 Distagon

The following applies to the Canon 5D and 5D Mark II

Like the 35mm F1.4, generally the 35mm F2.8 works fine for Canon 5D owners, but some owners have run into problems. Whether the issue was (is) the particular 5D body or adapter is unknown.

Contax 45mm F2.8 Tessar (Pancake Lens)

The following applies to the Canon 5D and 5D Mark II

Surprisingly the 45mm F2.8 Tessar can be another picky lens on the Canon 5D. Like all the lenses here thus far, mirror clearance can be hit or miss depending on the specific Canon 5D and adapter combination.

Contax 50mm F1.4 Planar

The following applies to the Canon 5D and 5D Mark II

Generally the 50mm F1.4 Planar will work on a Canon 5D without issue, but as always, there are exceptions. If this lens does not clear the mirror, I would suspect someone mucked the focus ring and tweaked infinity focus to their preferred taste.

Contax 50mm F1.7 Planar

The following applies to the Canon 5D and 5D Mark II

The 50mm F1.7 is commonly cited as having clearance issues with the Canon 5D. Whether a thicker adapter will resolve the problem is case by case. Whether or not infinity focus is compromised is another concern.

Contax 100mm F2 Planar

The following applies to the Canon 5D and 5D Mark II and the Canon 1D Series

The 100mm F2.0 Planar will fit; however, there is a metal fine on the rear of the mount. This fin may need to be filed down slightly. For more information, see the 100mm F2 Planar review.

Contax 135mm F2.0 Planar

The following applies to the Canon 5D and 5D Mark II and the Canon 1D Series

The 135mm F2.0 Planar will fit; however, there is a metal fine on the rear of the mount. This fin may need to be filed down slightly. For more information, see the 100mm F2 Planar review. Note - the Contax version of this lens can sell for a hefty premium, and frankly, its performance can be lacking. The Zeiss 135mm f/2 Apo Sonnar T* ZE is a much better choice.

CONTAX / CANON EF ADAPTERS

Ebay and other similar marketplaces have 100's of cheap adapters offered for sale. The quality of these adapters is often sketchy at best - such as improper thickness, even even thickness, plating that flakes away, poor fit (wiggle / wobble), etc. My preferred adapter is Leitax because they are actually screwed to the Contax lens, providing a very secure connection with no play or wobble. For more info on Leitax adapters, check out my reviews.

A WORD OF CAUTION WHEN PURCHASING USED LENSES

A common discussion on user forums is how to adjust infinity focus. Generally, this can be done by rolling back the rubber grip on the focus ring (if there is any) which reveals the screws holding the focus ring in place. Loosening the screws allows the focus ring to be repositioned. This adjustment can be disastrous on a floating element lens design. These lenses were designed for the exit pupil to be an exact distance from the film plane. If that distance is compromised, lens performance will suffer.

Such adjustments may negatively impact lens without floating element designs too. Since the first person “optimized” lens for infinity focus with their adapter, it is likely the next person will have trouble finding an adapter that works properly. In effect this adjustment creates the “good copy / bad copy” syndrome. When buying a used lens - ask the seller if they have made any such adjustments. Ask if the lens has been sent to Leica to ensure proper calibration.

DISCLAIMERS

I try to make sure everything is correct; however, there are no guarantees. Be safe and do your own homework too. If you decide to mount a non-Canon lens to a Canon camera, you are doing so at your own risk. If something feels wrong --- stop and examine the adapter, the lens, etc. Using an Canon EOS / Contax adapter is usually trouble-free; however, there are exceptions. Until you know for sure a given lens and adapter combination works correctly with your camera, go slow and pay close attention.

As of 2011 the database is no longer updated.