Digital Outback Photo
- Photography using Digital SLRs


Non-Canon Lens Adapters

Expanding the range of your Canon Camera

field report by Paul Caldwell (8/10/2004)

Note: Be aware that using a non Canon adapter may invalidate your waranty or may damage your camera. You use these adapters on your own risk. We write this note that you cannot claim that we told you to use non Canon adapters. We just publish a personal report by Paul Calwell who does not have an issues so far. There incedents known that may be related using non Canon parts.


As an outdoor scenic photographer, I am always looking for a solution that will allow me to get the best possible resolution from my camera. In my case this is the Canon 1Ds or my older Kodak 560. In my work I tend to favor wide angle lenses starting at 35mm and going all the way to the 20mm range.

My first Canon lens was the 24-70L F2.8. I was very pleased with this lens, especially in the 24mm to 35mm range. However in the first year I was carrying it, I often would find that I was mainly staying around the 28mm focal length. The 24-70 is a fairly large and heavy lens so I decided to check out the Canon Primes that were available. This would allow me to save in both bulk and weight. Plus most photographers will agree that a prime lens at any focal length is always sharper than a zoom lens.

I quickly eliminated the Canon 35mm F1.4 and 24mm 1.4. Both are great performers but they are rather large and expensive. I then moved to the Canon F2.8 28mm and 20mm but after reading many user reports on these two lenses, I decided that they were not going to provide the higher resolution I was after. Many of the reports I read actually favored the resolving power of the 24-70L lens over the Canon 28mm F2.8. It was about this time that some web posts caught my eye in regards to using the Contax Distagon lenses on Canon cameras. The ability to use these non-Canon lenses is allowed because of some interesting facets in regards to the Canon body design.

First of all, Canon uses a larger diameter with their lens opening with a shorter retro focus distance (the distance from the exit pupil to the film plane). In layman’s terms, if you want to design an adapter for a 3rd party lens, if that lens has a greater retro focus distance; it’s not a hard thing to do. There is space available to allow for the thickness of the adapter, without it becoming an extension tube. In fact it’s easier to use non-Canon optics on the EF mount rather than the older Canon FD lenses. The FD and EF mount have very close if not identical retro focus distances. The FD mount used a breech-lock mount; the EF mount uses the modern bayonet style mount. To create an adapter to go from FD breech-lock to EF bayonet mount would require a thicker adapter, than a non-Canon Bayonet mount. The thicker adapter would tend to act like an extension tube and thus you would lose infinity focus.

Because of this, you can pick from a large number of non-Canon optics; Nikon, Contax and Leica are the ones that come to mind most often. There is another advantage for Canon users. With many of Nikon’s current digital bodies, the older AI Nikkor’s will not meter, an exception to this is the new D2H. The older AI Nikkor’s were mostly manual focus but had some of the best glass that Nikon ever made. In the last 2 years, the number of the AI Nikkor’s on eBay has grown tremendously and a good shopper can get some great deals.

If you use a non-EOS lens on a 1Ds there are a few issues that you have to contend with.

1. Manual focus
2. Metering
3. An adapter to go between the non-EOS lens and the Canon body

Let’s cover each of these issues.

Manual focus

To some this is a big issue especially an event shooter or a sports/action shooter. For me it’s really a “non issue”. This is especially true with some of the Contax Distagon wide angle lenses as they have such a reach of range at infinity. I have heard the expression, “With a distagon at infinity, anything from your toes to the furthest tree in the distance will all be in sharp focus”. The Contax Distagon 28mm F2.8 for example at infinity focus is sharp from 5 feet out. I personally feel that for close up work manual focus is not an issue either as I tend to always be in non-AF mode when I work close up. However if I am shooting birds, I am always in AF mode which is one reason I haven’t scooped up an old Nikon F2.8 400 AI by now.


This is a more critical subject. The ability to get good information to the camera in regards to ambient lighting is very important. When you first put one of these non-Canon lenses on your EOS body, it’s quite a shock when you look for your aperture setting on the top LCD and see a 0.0.

Basically the vast majority of these adapters will allow you to work with your EOS body in M mode and Av mode. All the metering modes such as spot and center-weighted will still work. However since you no longer have an EF lens on your EOS body, there is no automatic stop down. So to meter correctly, you manually set your shutter speed, then physically stop down the lens. I would recommend you focus first with the lens wide open to allow the maximum amount of light into the camera to assist you. Then stop down the lens and meter. This will take some getting used to and don’t be surprised if you take a few shots that are all washed out since you forgot and left the lens wide open.

I have also discovered that over time, you will gain a feel for the particular lens and metering will become easier. This is because as you use this setup you will begin to anticipate what settings will work for the given scene. Another advantage to digital is you can always check your work in the LCD by viewing the image, histogram or both

The non-EOS Lens adapter

There are many companies that currently market 3rd party adapters for the Canon system. Be aware that all of these are niche players in that usually the entire company will consist of one to five people. This means you most likely will have to deal directly with the company and lead times can be excessive. You also have to trust them to produce an adapter that won’t damage the contacts on your Canon body. It’s also important to make sure that the company you pick has produced the adapter out of solid materials and that it’s well machined. The tolerances of a modern camera are very slim and if one of the contacts doesn’t line up correctly this could lead to either damage or a err99. You also want to make sure that the adapter locks securely to your lens and has no play once it’s installed.

Some of the adapters currently on the market are listed below.

Novoflex (Nikon to EOS)
Bob Shell Adapters (Contax to EOS)
Cameraquest adapters (Contax/Nikon/Lecia and medium format to EOS)
Zoerk Adapters (Medium format to EOS)

I choose to work with the Cameraquest adapter for Contax to Canon EOS for my work.

The Cameraquest Adapter & Distagon Lenses

The basic Cameraquest adapter will slip in-between your Canon body and the lens. I found that for me it works better to mount the lens to the adapter, and then mount that combination to the camera. Remove it in reverse order. The Cameraquest adapter has a small lever/cam that you press in to release the lens from the adapter. In the pictures below you can see the adapter, the adapter mounted to the lens, and adapter/lens showing the release lever. The lens in this case is a Contax Distagon 35mm F2.8.

Image of the Cameraquest EOS-Contax adapter

View of the Contax distagon lens and Cameraquest adapter

Red arrows points to release lever

Once you have mounted it you will hardly know you have anything there. The adapter itself takes up a very small amount of space. Cameraquest makes their adapters from material that is as strong as the Canon lens mount metal. Notice in the image below, since the adapter is black it blends in with the camera very well.

Canon 1Ds with Cameraquest/Contax lens mounted

The Contax Distagon lenses have a huge cult following. After hearing about how sharp they were on the 1Ds, I had to try one. I picked the 28mm F2.8 for my testing. The lens itself is small and compact with easily read markings on the outside. The focus ring and aperture rings are made with good grips and locating them while operating the camera is an easy task. The lens is threaded for a 55mm filter ring.

Here are all the Distagons that Contax makes that I am aware of.
18mm F 3.5
21mm F 2.8*
24mm F 2.8
28mm F 2.0*
28mm F 2.8*
35mm F 2.8

* Superior performers in this series. (Based on other photographers reports and my own testing)

You can still purchase most of these lenses new, however they are found all over the web used or from brokers like KEH camera. I purchased all of mine used over the web.

What to expect?

This is a fair question after all you just put a much older piece of technology on the 1K - 7K camera you own. My results were stellar.

Here are my results when I tested the Contax 28mm F2.8 Distagon against my 24-70L EOS lens. I kept my aperture at F11 or F8 on both lenses and all my testing was done outdoors, at some of my favorite locations.

1. The 28mm F2.8 Contax was sharper all the way to the corners on every shot. When looking at the various test images I found that the center areas of each image were very close from both the 24-70L and the Contax Distagon 28mm. But when you looked at each image at a 100% view, often times, you would see the sharpness fading on the images taken with the 24-70L as you moved out to the corners. This wasn’t true with the Contax Distagon.

2. I was never able to get the Contax 28mm F 2.8 to produce CA (Chromatic Aberration) even in extreme lighting situations. The 24-70 tended to produce CA much more often especially when fine objects were against the sky like fine tree limbs.

3. With the Contax 28mm any normal height filter mounted tended to vignette (darkened in the corners). The 24-70 with a two stack of normal height filters didn’t. To get around this, I started using my 72mm filters on the Contax 28mm. I used a 72mm to 55mm step down ring to accomplish this.

4. In most situations the Contax 28mm was slightly cooler in all colors than the Canon 24-70L lens. This was most noticeable in the greens. The color issue is an easy correction and in many cases, I found I preferred the Contax colors anyway.

5. The Contax 28mm Distagon at F8 or F11 hardly ever needed a focus correction as anything from 5.5 feet or out was sharp. With the 24-70L Canon, I found that I had to often make focus corrections for the foreground over the background and bracket the images later in Photoshop. This is a common problem with all wide angle zooms.

The conclusion for me was that the Contax Distagon 28mm was a “keeper” and has become a permanent addition to my bag. Since I mainly used the 24-70L in the 24-35mm range, I quit carrying it in the field and have come close to selling it a few times recently. Since I started this process, I have added several non-Canon lenses to my collection. Some of these are:

Nikkor AI 50mm 1.4
Contax Distagon 28mm, 35mm both F2.8
Contax Planer 50mm 1.4
Mamiya 35mm F 3.5
Nikkor 45mm F2.8 (Tessar design)

Currently I would have to say that in my outdoor work, I use non-Canon glass at least 85 to 90% of the time.


  • Expands your investment in a Canon system by allowing you to work with some very good non-Canon Glass
  • Price point on these non-Canon lenses is very reasonable
  • The Contax Distagon Wide Angle Series produce Amazingly Sharp/crisp/detailed images
  • You can carry several of these lenses and have less overall weight/bulk in your pack


  • Loss of Autofocus
  • Metering only will work in Av and M mode on most Canon Bodies
  • Most of the adapter companies are niche players


Many thanks to Stan Disbrow for his help on the discussion of the Canon Mount and the optical issues of non-Canon lenses.

Sources for further information

Zoerk Adapters----
Bob Shell Adapters---
Cameraquest Adapters---
Novoflex adapters---

Please feel free to ask me any questions directly. I can be reached at the following email address:


For Comments post in our News Group

2000-2007 Digital Outback Photo