| Author |
Message |
    
Jonwoolf
Tinkerer
Username: Jonwoolf
Post Number: 1
Registered: 05-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 21, 2012 - 03:30 pm: | 
|
Hi guys- I am new at this forum, so PLEASE don't laugh if I am asking a stupid question!! I was lucky enough to buy a Canon A-1 at an estate sale recently- looks very clean. It has 3 lenses with it, all FD Canons. A 70-150 zoom, a 17, and a 50 macro.
Now, here's the question. If I look through the lens, and change the stop, the ring turns, but the iris leaves don't move. Is this normal? I could understand if one of the three lenses were doing it, (maybe a stuck iris), but all 3??? Also, if the iris was stuck in all 3, wouldn't I feel the jam while trying to turn the ring?? Am I overlooking something simple? (Hope so!) |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 176
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, May 21, 2012 - 03:51 pm: |
|
The iris (aperture) will only close down when the shutter button is released. This is so you can focus while the lens is wide open and your viewfinder will be nice and bright. When you press the shutter button, the aperture closes just before the shutter opens and records the image.
The A-1 also has a depth of field preview button. When you press this button, the lens will "stop down" (close the iris) so you can see what will be in focus in the image.
Check out www.butkus.org for an on-line manual for the camera. |
Glenn
Tinkerer
Username: Glenn
Post Number: 1000
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 23, 2012 - 09:47 am: |
|
Jon,
Welcome to the Forum. Please follow Wayne's advice and get yourself a copy of the A1 manual - the camera is not particularly complicated but there are one or two things that can catch out a person who is not experienced in its operation. As has been stated the iris of the FD lens only functions correctly when mounted on the camera - mount the lens and set aperture to f16, set shutter to B or 1 sec and looking into front of lens press the shutter release. You will now see the iris function properly, if you looked through the viewfinder whilst doing this the mirror would black out the finder.
You should also note that it is impossible to get the aperture to function with the lens off the camera unless a special item is attached to the rear of the FD lens. The attachment (basically a rear lens cap with the end cut out) is called the 'Macro Hood' and allows lens apertures to be manually set when said lens is reverse mounted on macro bellows etc. Your special 50mm Macro lens allows 1:1 reproduction without the need to have bellows or reversal rings etc. In fact you have a nice selection of lenses there, the 17mm is a particular favourite of mine for architectural work, so you should have some fun with the kit |
Thepurush
Tinkerer
Username: Thepurush
Post Number: 37
Registered: 01-2012
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, May 25, 2012 - 08:36 am: |
|
Yes, unlike many other lenses, in Canon lenses the aperture remains open irrespective of aperture ring position. The blades close to the set value only during exposure. While testing you can always manually close the blades by turning the only projection you see behind lense. Rest assured thre is nothing wrong with yoyr lenses if youcan do this. |
Glenn
Tinkerer
Username: Glenn
Post Number: 1004
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, May 26, 2012 - 06:23 pm: |
|
Do not know quite what the last poster is trying to say. All FD and nFD lenses made to the relevant Canon patents have their iris operating mechanisms locked by the very action of removing the lens from the camera body. The TWO silver 'levers' projecting from the rear of the inner mount cannot be moved by finger pressure when lens is off the body. One needs to attach a spare male camera body mount, macro hood, or short extension tube to the lens to unlock the mechanism. As I have stated before, a device almost the same as the macro hood can be made by cutting the end out of the relevant rear lens cap. In the case of the cap for the nFD lenses (has the serrated finger grip) one has to remove the rotation up-stands from the three portions of plastic flange. |
|
