I recently acquired a Canon D30 body and got an EOS-FD adapter to use my old macro lens with it if nothing else. Since the adapter I got had optics (easily removable) to adjust for the different lens registrations and I'd never heard a good word about any of these adapters, I decided to give its optics a try.
I used a Canon FDn 135/2.0 to take a picture of a plant on my windowsill both with the adapter lens and with the adapter lens removed (ie. as a plain mount adapter). The lens was set to f4 and exposure time was 1/45 sec. The camera was the aforementioned D30 set to ISO 100 and installed on a tripod. I also took a picture of my bookshelf with aperture set to f4 and Av auto-exposure. Images were processed from raw files using a trial version of Phase One CaptureOne Pro with default settings except that sharpening was disabled, then converted to sRGB color space and saved as JPEGs.
The following images were obtained:
The EOS-FD adapter's lens acts as a short tele-extender so the perspective is different in the plant pictures. The bookshelf picture without the adapter lens had to be taken closer to the shelf due to limited focusing range. The focus on the "with adapter" bookshelf picture is perhaps slightly off; no prism on the standard focus screen.
At f4, there is noticeable extra softness and coma in the corners. There is also some general loss of contrast and softening overall. But contrary to expectations, output was not totally terrible. The adapter seems sort of usable with its correcting lens with a low-resolution small-sensor digital body such as the D30. It feels sort of like making my FD glass emulate '50s Tessars. I probably wouldn't want to see how it looks like with a full 35mm frame though.
Informal testing with a 50/1.4 with various apertures indicates that opening up beyond f4 soon gives you enough soft focus to set up a teen fashion magazine on the spot. If I ever get around to it, shooting some real resolution test targets might be interesting.
The adapter (picture) says "KOOD CANON (AF)/FD JAPAN" on it. Based on how it looks, it's probably the same adapter sold by some stores with the Hama label and on ebay as totally unbranded. It seems to be made of metal. Mounting is fairly smooth, but with FDn lenses you have to turn a ring on the outer perimeter that pushes the lens's aperture lever to close the shutter.
The adapter adds approximately 7mm between the lens and the body. With the 135mm lens, "infinity" focus is at around 1.5 meters without the adapter's correcting lens. The adapter's opening is fairly small and appears to limit the maximum effective aperture to somewhere between f2.8 and f4. The adapter lens consists of two elements held together by a metal ring. The elements don't seem to be coated and looking against the light with a large aperture there is noticeable loss of contrast in the viewfinder.
You can contact me by mail at vuori@sci.fi if you have questions or comments about this test.
Back to my pictures page.
- May 2005
