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Raine
Tinkerer
Username: Raine
Post Number: 1
Registered: 01-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 21, 2011 - 04:36 pm: | 
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Hello, I am very new here!
I have a Minolta SRT-101 that I purchased from Value Village a few years ago. I've been using it for three years without error, almost all pictures come out properly exposed. I've never had any problems with it.
I'm now taking an official darkroom class, and my prof told me that my f stops aren't working. I have two different lenses and she told me they aren't working on either of them. I can't see it click through different apertures when I switch them, but I'm not sure if that's even supposed to happen. When I remove the lenses and switch through the f stops with them removed I can see them changing sizes.
Are they broken...? Why would both of my lenses be broken? I don't think she knows what she is talking about. The lenses are a Spiratone Plura-Coat 1:28 f=28mm and a MD Rokkor 50mm 1:1.7 49mm.
Thank you! I really don't want to have to use my nikon n40. |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 16
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 21, 2011 - 06:14 pm: |
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First, check the lenses.
You say that the aperture changes size when off of the camera. Put the Aperture at f16 and then operate the little lever on the back of the lens.
If the aperture opens and then snaps back to its original size, the lens is OK. If it is slow to close or return, it may be sticking and needs cleaning (this can affect your photos, especially when using fast shutter speeds).
Now, check the camera.
With the lens off, look into the camera from the front. At the bottom of the lens mount you should see a little arm pointing to the right. When you fire the shutter, the arm should move rapidly to the left and snap back. This is what actuates the aperture.
If this doesn't happen, try pushing the chrome button on the left hand side bottom of the lens mount. This is the depth of field preview that manually operates the aperture.
If both of these checks look normal, then mount a lens on the camera, set a long shutter speed, open the back of the camera and look through it while firing the shutter. You should be able to see the lens stop down and then open up again. |
Milosdevino
Tinkerer
Username: Milosdevino
Post Number: 14
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 21, 2011 - 06:37 pm: |
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You're right, she doesn't have a clue. On all slr cameras the aperture stays wide open until you release the shutter. It would be too hard to see through the lens otherwise. Imagine trying to focus with the apperture set at f22, it would be very dark. Once the shutter is tripped, the mirror flicks up, the apperture stops down to whatever it was set at and the shutter curtains open. Set the shutter to 1/30 or 1/15 and look through the film gate as you set it off. The diaphram will stop down to it's setting. Then show your professor. |
Raine
Tinkerer
Username: Raine
Post Number: 2
Registered: 01-2011
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 22, 2011 - 02:14 pm: |
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Milosdevino- thank you! that helped. I don't know why a self taught value village photographer of four years knew this and a 40+ lab tech didn't.... |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 37
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 22, 2011 - 06:02 pm: |
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She may have been confused, thinking your cameras were stop-down metering models. With the advent of automatic aperture, all that business of having to focus-then-meter stopped, unless you were using what is known as a pre-set lens. There are still plenty of those out there, especially the T-mount 400mm and above. And any T or T2-mount lens is a pre-set.
PF |
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