To connect my Canon lenses to the Sony A7R, I use the Metabones Canon EF Lens to Sony NEX Smart Adapter (Mark III). There is a lot of chatter on the web about internal reflections within this adapter leading to unwanted flare and low contrast images. I can tell you from personal experience this is completely true. My friend, Achim Sieger, was amongst the first people to point out to me this simple yet elegant solution. It involves lining the inner surface of the adapter with black adhesive flock paper, a material excellent at absorbing light.
For those of you out there wondering how this is done, I’ve put together this step-by-step tutorial, illustrated with images. The process involves taking apart some of the mechanical components of the adapter, so be cognizant of that and venture forth at your own risk. I hope you find the instructions helpful, and please feel free to ask questions. I’ll do my best to answer as clearly as possible.
Step 1: Obtain the necessary tools and paper.
I chose: #55 Adhesive Back Flock Paper, 8″ x 10″, 5 Sheets (Figure 1)
Tools: #0 Phillips head screwdriver and smaller Alan wrench that came with you Metabones smart adapter (Figure 2) and an Exacto knife (or scalpel) (Figure 3)
Step 2: Remove the metal mounts from the adapter (Figures 4-7)
Step 3: Remove the inner plastic components (Figure 8, 9) – rectangular and circular. The rectangular shaped plastic component is actually two separate pieces held together by two screws. Separate these components by removing the screws.
Step 4: Cut a rectangular piece of the block flock paper big enough to coat the inner surface of the square plastic components (Figure 10). Trim away the excess flock paper with the Exacto knife.
Step 5: Repeat step 4 for the circular component, using the Exacto knife to cut out the inner circle and hole for the connector (Figure 11).
Step 6: Reassemble the rectangular components with its two screws. Your two plastic pieces (rectangular and circular) should look like what you see in Figure 12.
Step 7: Put the plastic pieces back into the adapter and reassemble the metal mounts. The final product should look like Figure 13.