I acted upon the suggestion in the Forum to get an adapter to use my FD lenses on digital. I bought one and today tried it out on my Canon 350D. I checked on the net for the correct way to fit it but have not had much luck finding trouble shoots for my problem. Having fitted my FDn 50mm F1.4 with adapter on the camera, I took a few dozen shots, stopping every few shots to examine the images and wonder what my problem was. The lens stopped down, this confirmed when closing the adapter. I set the camera to AV. The camera reported I was using an 80mm lens (probably due to using my 28-80mm prior to the 50mm) and the last AV value (F8) I had used with an EOS lens. I took a few images and the results were all over exposed to some extent, sometimes very over exposed. I matched the AV value on the camera to the lens and tried again. I tried changing the ISO My suspicion is that the contacts on the adapter are confusing the camera, maybe I should remove them. Any help here would be appreciated, my one correctly exposed image indicates that the FD lenses might produce reasonable images with this adapter in some circumstances. Some images of the adapter and one good image, one bad (but not as overexposed as some!)
I too have a adapter for the FD to EOS and use a large number of FD lenses on my digital canon cameras and have not had this issue but my adapter does not have the contacts, The FD lenses are getting a bit old, you might also be having an issue with the lens.
The lens worked fine on the T90 last time out but I did try another lens with same result. On a Pentax there is an option in the menu to enable use of manual lenses and use the "green button" for metering. I can find no reference to this on Canon. I might try masking the contacts on the adapter before removing them.
When I shoot I do so in M or AV, a silly question but are you shooting in either of these two modes as I don't think it works in any of the others
Camera in AV mode. Logically it should meter when I have stopped the adapter down and provide the correct shutter speed. Sometime tomorrow I will put sellotape over the contacts on the adapter and try it again, perhaps they are confusing the camera.
I have a MD to EOS, a M42 to EOS, a Tamron to EOS as well as the FD adapter. In each case the lenses are similar to the FD, manual focus and manual Aperture. I can adjust the ISO, Shutter Speed and read the light meter when using the camera with no problem. You maybe correct in putting electrical tape over the contacts as they seem to be causing your camera to give a false reading, none of my adapters have the contacts on them.
I will tape up the contacts and go again. I see on the WWW that some early EOS digital cameras had overexposure problems when using manual lenses on adapters, overexposure increasing slightly as the aperture was stopped down. The posters suggested that the graduation increase was pretty linear and could be compensated for. At the moment mine are not easily compensated for.
The camera works properly (well with a tiny bit of over exposure) now I have taped the contacts up. The exif no longer specifies it as an 80mm lens so all is in working order. Tried it on a 20D as well with the contacts taped and it needed 2 stops of compensation but it metered fairly consistently. Without tape it was all over (overexposed) the place still. Taping the contacts have done the trick! Thanks to Craig Sherriff who offered help.
I have purchased a M42 to EF adapter with a flange to stop down the auto pin on M42 lenses that do not have a manual stop down facility and I don't want to glue or sleeve the pin. It has no contacts so no focus confirm (or exposure problems from contacts that are not working as they should!) and obviously no AF, IS and probably inferior coatings on the old M42 lenses. But if the user can manual focus happily it lets the Canon user access some very cheap if old prime lenses. It does need to have -2 ev compensation applied like the other adapters I have tried. Trying it out with an old Petri 135mm F2.8 Image plus crop , and a pic of the adapter, came in a plastic sleeve, a box, a bubble and thick plastic bag.
You do get good results, using the adapter and m42 mount lenses. you can improve upon them using a view finder loupe attached to the viewing screen on the camera. It is not necessary for taking good photos but I find one helps to improve my focusing and the removes the sun's glare on the viewing screen on the camera. I paid 12 dollars (Australian currency) for a cheap one from China. The photo shows the one I have attached to my 60D. One problem though when I am using it, people tend to come up to me wanting to know what sort of weird camera I am using
Looking at your adaptor I can see that is just a device that allows you to fit the lens to the camera and give you manual control of focusing and aperture. The little board with the contacts is just a focus confirm PCB, it will not transfer any relevant information from the lens to the camera although the chip has information programmed into it and these will usually tell the camera it has a 50mm f2 lens fitted. All focusing and should be done at the widest aperture of the lens then you should stop the aperture down just before taking the picture. Manual focus lenses often do tend to give slightly underexposed readings when stopped down. Do not match the aperture Settings in AV on the camera this will give you enormous exposure errors, leave the camera display set to f2 or whatever the adaptor defaults to. If your adaptor is not reporting any focal length and aperture settings apart from those of a previously fitted lens then I would suggest that it is either faulty or not correctly aligned with the camera contacts.