dpatt711 Posted February 18, 2023 Share Posted February 18, 2023 Using the stop down lever on my Canon T90, my 28mm works as expected but the 100mm does nothing. There is noise when I set it back into Auto and the lever feels normal Link to comment Share on other sites More sharing options...
jim_bielecki1 Posted February 18, 2023 Share Posted February 18, 2023 Breechlock or FDn? What happens when you shoot on manual? My guess is you may have oil on the aperture blades. Link to comment Share on other sites More sharing options...
dpatt711 Posted February 18, 2023 Author Share Posted February 18, 2023 3 hours ago, jim_bielecki1 said: Breechlock or FDn? What happens when you shoot on manual? My guess is you may have oil on the aperture blades. FDn. I'm not really sure what happens on manual, I have film loaded now so I'm not sure what to test for. Link to comment Share on other sites More sharing options...
SCL Posted February 18, 2023 Share Posted February 18, 2023 try dismounting it and remounting it. Perhaps the lever isn't fully catching. Link to comment Share on other sites More sharing options...
jim_bielecki1 Posted February 19, 2023 Share Posted February 19, 2023 20 hours ago, dpatt711 said: FDn. I'm not really sure what happens on manual, I have film loaded now so I'm not sure what to test for. Take the lens off the "A" mark, and put on F:11 or something. Set the shutter speed to "B", and press the shutter button while looking down into the lens. See if the lens is stopping down (you'll have to waste a frame of film). If not stopping down, you have a problem with the lens. Link to comment Share on other sites More sharing options...
dpatt711 Posted February 19, 2023 Author Share Posted February 19, 2023 Just now, jim_bielecki1 said: Take the lens off the "A" mark, and put on F:11 or something. Set the shutter speed to "B", and press the shutter button while looking down into the lens. See if the lens is stopping down (you'll have to waste a frame of film). If not stopping down, you have a problem with the lens. Yep aperture is definitely stuck open. Doesn't close at all. Link to comment Share on other sites More sharing options...
jim_bielecki1 Posted February 19, 2023 Share Posted February 19, 2023 2 hours ago, dpatt711 said: Yep aperture is definitely stuck open. Doesn't close at all. Most likely you have oil on the aperture blades (the lens was probably exposed to high temperatures at some point and grease melted). It will have to be taken apart and cleaned. Link to comment Share on other sites More sharing options...
dpatt711 Posted February 19, 2023 Author Share Posted February 19, 2023 45 minutes ago, jim_bielecki1 said: Most likely you have oil on the aperture blades (the lens was probably exposed to high temperatures at some point and grease melted). It will have to be taken apart and cleaned. Whats the best way to go about cleaning it? I don't have any tools or experience working on lens Link to comment Share on other sites More sharing options...
awahlster Posted February 19, 2023 Share Posted February 19, 2023 The best way is to send it to someone that does have the experience and tools to do the job. Link to comment Share on other sites More sharing options...
dpatt711 Posted February 20, 2023 Author Share Posted February 20, 2023 5 hours ago, awahlster said: The best way is to send it to someone that does have the experience and tools to do the job. Any recommendations? Link to comment Share on other sites More sharing options...
jim_bielecki1 Posted February 20, 2023 Share Posted February 20, 2023 9 minutes ago, dpatt711 said: Any recommendations? If you're in the U.S., Steve Sweringen, Camera Clinic, 100 2nd Avenue NW Mandan, ND 58554, 775-829-2244. Link to comment Share on other sites More sharing options...
chuck909 Posted February 20, 2023 Share Posted February 20, 2023 (edited) Sometimes some healthy exercise will bring it back to life. I have a 20mm FD that had that problem. Yes, I could see the oil on the blades. I spent hours off and on trying to get it to stop down. Nothing at first, but little by little it finally agreed to do as I asked. I make it a point to exercise all of my lenses. Beats taking it apart. Edited February 20, 2023 by chuck909 Link to comment Share on other sites More sharing options...
gwhitegeog Posted February 21, 2023 Share Posted February 21, 2023 Yes, regular exercise of all my FD lenses and FD era 35mm camera bodies. Store in a cool, well ventilated (but not cold) dry place with professional packs of silica gel (large pouches) and store the equipment in a aluminum / metal rigid box / trunk with dividers* but with air able to circulate around - no 'cut to fit' foam, which breaks down imperceptibly and emits acrid and corrosive fumes (over several years) IMHO. I even keep a spreadsheets (10 bodies and about 25 lenses, Canon and some Nikon) which records all the information I have about the bodies / lenses and when it was last actuated. *Unless you are transporting them, in which case you'll need padding. Link to comment Share on other sites More sharing options...
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