LEICA-R CANON COMPATIBILITY DATABASE
What Makes a Good Canon EOS / Leica-R adapter for Canon dSLRs
Leica-R To Canon EF Adapters FOR CANON DSLRs

WHAT MAKES A GOOD ADAPTER
Ebay offers many, many different Leica R / EOS adapters at varying prices points. Finding the right adapter requires some homework, experimentation and communication. ‘Google’ the seller and look for user reviews in photography forums such as Fred Miranda or the Manual Focus Forum. See what other users are saying about the adapter’s build quality, fit and finish and operational performance. Most likely the results will be mixed with some people loving or hating the adapter in question. Why the conflicting reports? Some possible reasons include:
•Proper Thickness - Adapter thickness is probably the most common quality issue. If an adapter is too thick then the lens will not focus to infinity. If the adapter is too thin, then images may look out-of-focus, or worse yet, the mirror will hang on the rear element assembly. If the lens has a fixed rear element the distance from the rear element to the film plane is fixed, an adapter that is too thick or too thin adapter may result degraded optical performance.
•Variance in Production - Some adapters are poorly designed, while others are designed well but fabrication variances cause problems, such as poor quality control during plating process could lead to increased thickness. Some adapters have paint finishes which add to the adapter’s overall thickness. The majority of the adapter from China are not high grade, so do not expect too much for a $19.99 Ebay special. The generally accepted thickness for a Leica-R Canon EOS adapter is 3mm.
•Uniform Thickness - As mentioned already, an adapter may have poor quality plating with high spots and low spots, thus the lens may sit slightly crooked. A crooked lens may result in one side of the image looking sharper than the other. At F8, F11 and up depth of field usually hides the problem, but at faster apertures such as F1.4 and F2 this can result in one side of the image being sharper than the opposite side.
•Canon 5D and 5D Mark II Variances - It is quite common to see Canon 5D owners disagree regarding which lens / adapter combo work. Most likely due to shimming (to align the sensor, viewfinder and mirror) in the production process, the Canon 5D’s and 5D Mark II’s vary in mirror box specifications. Some people are lucky and they have a Canon 5D which has the mirror pushed back slightly further, and they experience fewer issues. Whereas other cameras may have the mirror slightly forward and the mirror hangs on a lot of different lenses.
It is difficult to pinpoint the Canon 5D as the culprit because there are also adapter variances and lens variances. Which brings us to another key consideration. Many of the R lenses are 10, 20 or 30 years old. Many lenses have been serviced, components have worn and the lens may have led a tough life. There are some hobbyists who like to “optimize” their lens’ and adjust the focus ring for infinity for their specific camera, thus potentially mucking up the lens for the next owner. Lens condition is a key variable.
FOCUS CONFIRMATION ADAPTERS
My favorite adapters are the newer focus confirmation adapters sold by Leitax. As the focus ring is turned, the Canon AF light blinks and the camera beeps when focus is achieved. In my experience the AF confirmation adapters have proven reasonably accurate. When paired with Canon ECs type focus screens, the combination work well together. Focus confirmation adapters are not fool-proof. Focus confirmation chips tend to work better with the primes and not quite as well with zooms. Part of the reason is the slower aperture for most zooms, thus less light coming into the chamber. Canon auto-focus lenses can struggle in dim conditions, and the same is true with the focus confirmation chips.
PROGRAMMING AF CONFIRMATION CHIPS
The two prevailing types are the Optix V5 and the Dandelion. Based on my experience, both chips seem equally effective. One of the big improvements is that the end-user can now program their own chip with lens’ focal length and widest aperture. I prefer the Optix V5 set-up process, which uses multiple Canon DOF button pushes to activate the program mode, the Canon front control wheel to select and DOF button pushes to store the parameters. This programming sets are not an on-screen process, so it is critical to pay careful attention to the instructions and the variance flashing aperture messages - see the Optix V5 instructions here. Both the Optix V5 and Dandelion chip offer micro focus adjustment parameters to adjust for front or back focus. (Continued on the next page)