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05/11/2005 11:36:32 AM · #1 |
Anyone know how to change the aperture of an old FD lens absent a body? I have just bought a cheap lens and reverse coupling ring to try some macro photography, but the lens I have bought is in the middle/emd of the F-Stops. I would like to open it up as I am getting some serious vignetting at the moment.
I have an Av ring on the lens, which does not do anything to the blades when twiddled. I have two levers on the back of the lens. One moves freely, the other one is untuggably stuck.
Any ideas?
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05/11/2005 11:52:01 AM · #2 |
Originally posted by legalbeagle:
Anyone know how to change the aperture of an old FD lens absent a body? I have just bought a cheap lens and reverse coupling ring to try some macro photography, but the lens I have bought is in the middle/emd of the F-Stops. I would like to open it up as I am getting some serious vignetting at the moment.
I have an Av ring on the lens, which does not do anything to the blades when twiddled. I have two levers on the back of the lens. One moves freely, the other one is untuggably stuck.
Any ideas? |
Do you have it set on auto? THe apature ring should move freely, off the camera_. FD is an older model lens for F series canon cameras and may not work at all on the the 20D. The untuggably stuck lever (set ring) probably is the shorter of the two and is not supposed to move outside the camera.
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05/11/2005 12:14:01 PM · #3 |
with a reverse coupling ring the mount of the lens doesnt matter. once i go to my parents house i will look at all my dad's old fd lenses. Legalbeagle: where did you get the coupling ring? and how cheap is cheap?
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05/11/2005 12:34:53 PM · #4 |
I paid £22 ($35) for an "as new - and it is v clean) 50mm lens on Ebay - though I can see a couple cheaper on buy it now at the moment. I paid $11 for a coupling ring of correct diameter, again through Ebay (still waiting for it to arrive from the US). Strictly speaking, I did not need to buy Canon, and there are cheaper lenses that can be bought, but I thought that it seemed neater.
Practising by holding 2 50mm lenses together face to face, I can take photos that are almost microscopic - however, need to move camera around to focus and DoF is tiny! Huge vignetting at the moment because the cheap FD lens is stuck on about F22.
The aperture ring does move freely, but it does not seem to move the aperture ring blades - that might be expected if, as I suspect, the lens stops up or down when connected to a camera, and possibly only when taking a photo (hence DoF preview buttons on modern SLR). But it could just be a broken lens! Thanks for your offer of help, in that regard lemondster - much appreciated.
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05/11/2005 01:59:14 PM · #5 |
Sorry, had to go to a shoot, back now.
The shutter blades will not move off the camera. I don't know if this will help in your very interesting endeavor, but hold the lens facing you, while looking into the lens_watch the shutter blades as you turn the body cap as if you where putting it on and taking it off. The shutter blades should open and close. NOW_still watching, turn the body cap part way(about half, give or take a little) and change the appeture_the blades should move appropriately. By doing this you will know if the shutter is working...... MAYBE.
Message edited by author 2005-05-11 14:00:24. |
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05/11/2005 02:05:30 PM · #6 |
sofapez presents what is potentially the solution for your problem... if mounting a body cap to the lens fully opens the aperture, then simply cut out the center of the cap and mount it permanently. For macro work, yo ualways want the lens full open anyhow.
An alternative is to work with the mechanism until you discover what combination of actuation is required to open the aperture, and find a "creative" way to lock it in that position. A final approack would be partially disassemble, manually lock the aperture open, and reassemble.
I recently bought an old 50/1.4 lens fo rthis purpose as well. I chose an Asahi Optical Super Takumar, which is completely manual, making the adaptation very easy. |
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05/11/2005 07:26:15 PM · #7 |
Comments appreciated.
I went to my locl pro shop this evening, who told me and showed me that Canon FD is too advanced for off-camera aperture control - who knew that Canon were so good 20 years ago?? Stopping down is moved to an on-body control. Do not buy a nice FD lens for reverse coupling macro photo work.
They sold me a £10 "Cosina" lens, made in Japan, with similar characteristics. Am still waiting for the coupling ring, but my god - it is like using a microscope. amazing detail (cannot see stuff that I can see on the camera back even after I take a photo of it and know it is there), but the DoF is shockingly small. And still vignetting. May have to look for another, bigger lense and a stepping ring to get the right size result.
Many thanks for all the comments and assistance - always appreciated. |
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