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Message |
    
Eok3
Tinkerer
Username: Eok3
Post Number: 1
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 12:13 pm: | 
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hi,
my 50mm 1.4 works fine, except that the aperture pin just floats in and out. it isn't engaging whatever is inside that makes the lens stop down. i am assuming that whatever is in there is stuck. is there any site, or can anyone tell me how to take this apart to attempt to fix it? |
Jan
Tinkerer
Username: Jan
Post Number: 17
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 27, 2006 - 05:22 pm: |
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I believe I have downloaded a strip-down procedure for that lens from somewhere on the net. Send me an email by clicking on my user name and follow the link on the bottom of the page.
I am sure it is on my home computer and I can email it to you.
Good luck,
Jan |
Jan
Tinkerer
Username: Jan
Post Number: 19
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 28, 2006 - 11:19 am: |
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Gene,
You have the strip-down procedure now and I just wanted to let you know the following:
Make sure that your lens' Auto/Manual ring is set to Auto. If set to manual, the aperture pin will do what you originally described. Does the diaphragm close down when you turn the aperture ring? What camera are you using the lens on? The SMC version of the Takumar has a special tiny pin which disengages the Auto/Manual ring when the lens is used on a full aperture metering Pentax (F, ES and ESII). The ring will work properly when the lens is mounted on any stop-down metering Spotmatic.
Just to make sure that you knew about this....
Good luck,
Jan |
Jan
Tinkerer
Username: Jan
Post Number: 20
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 28, 2006 - 01:07 pm: |
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Gene,
Have a look at your two lenses from the back. On SMC Takumar, on the surface which mates with the lens mount, at about 3:00 o'clock, you will see a tiny pin. This pin gets pushed in when you mount the lens on an older stop-down metering Spotmatic. The newer open-aperture metering Pentaxes have a recess in their lens mount, which prevents this pin from being pushed in and also blocks the Auto/Manual lever on the lens.
Can you move the Auto/Manual lever from Auto to Manual mode? Also - the rear element of your SMCT can be removed and by extending the lens' focus to the closest distance, you should be able to peek inside at the linkage. I think your problem lies in the tiny pin described above. Make sure that the Auto/Manual lever operates as I am describing. From your description of what the lens is doing, I think that the lens is set to manual. That is what disengages the stop-down pin and makes it feel as if there is nothing behind it. The aperture will close down when you turn the aperture ring of course, because the lens would be in manual mode.
Check that.
Good luck,
Jan |
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