 Dave R. Mikkelson |
lens compatability Does anyone know anything about this lens:Canon Telephoto Lens FD 300mm 1:2.8 L? Will it fit and work with my Canon 20d? That is the main question.
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John Nunziato |
Dave, The answer is that this is a bayonet mount and will not fit .. Only ef lenses will. jn
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Dave R. Mikkelson |
I kind of figured but thought that there may be a chance. Thanks for the feedback.
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Jon Close |
There are adapters for fitting FD lenses to EOS bodies, but they have some drawbacks. Generally they are not worth the bother, but if you already have the FD 300 f/2.8L lens (a fabulous piece) or can buy it cheap, then it may be worthwhile. Because the distance between the mount flange and film/sensor plane was increased when Canon introduced the EOS cameras, the FD/EOS adapter necessarily needs to include optical elements to maintain infinity focus. These also act as a 1.26x teleconverter. There is no communication or mechanical connection between the FD lens and EOS body, so metering must be done by stop-down method in mode M or Av modes only (with the aperture value on the camera set to "00"). Set the aperture wide open to focus, then stop it down to the desired setting to meter and shoot. For a short time in the late 1980's Canon made their own adapter. It is rare and highly sought after and commands a premium price because of its superior optics. See this LINK. More common are 3rd party adapters. The optics in these are not so good, but may be usable. Some users will take the cheap adapter and knock out the optical elements. In that case the lens won't focus to infinity (can't shoot the moon), but is still usable for subjects from ~2.4m to 8m or so.
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Suzanne Colson |
I am not sure if I am going to ask this the right way, but what the heck... I have some cheap manual extension tubes which cause the behavior you have talked about above; no communication between the connections. If I use AV mode it shows '00' like you have stated. How do I actually stop the aperture down? I think there was actually a piece on the physical FD lens to do this, but there is not on the extension tubes I am talking about. If this is correct, is there a correct way to use them then?
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Jon Close |
Suzanne, if you are using FD, or other manual lens that has an aperture ring, you set the aperture wanted directly on the lens using that ring. If you are using an EF (Canon autofocus) lens on these extension tubes, then you cannot directly adjust the aperture. There is a workaround, though. Mount the lens directly to the camera, set the aperture desired, say f/11, then use the depth of field preview to stop the lens down. While the lens is stopped down, remove it from the camera - the aperture will stay at that setting. Then remount it onto the extension tube and on the camera.
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Suzanne Colson |
Thank you for the info. Yes, I am using an EF lens. If I set the aperture manually this way how do I control the exposure time and/or does the camera end up controlling it? Also, I should be using AV or P mode in this case as well, right?
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Jon Close |
In Av the camera will select the shutter speed. In M you can set it yourself. P and other auto modes should not be used with manual lenses, or your EF lenses on manual extension tubes since they set exposure thinking the aperture can be adjusted automatically.
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Suzanne Colson |
Thanks so much for the info Jon. To think maybe my pictures will come out now since I have a clue how to use them the right way!!
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Dave R. Mikkelson |
Thanks for the responses I actually learned more than I thought I would. I am not sure what cheap would be for this lens but I think it went for around $580.
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