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09-24-2009, 02:23 AM   #16
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Are you getting the green line by the 'A' lined up with the red dot or perhaps getting tricked by the green line lining up with the other green line?

09-24-2009, 07:38 AM   #17
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i have green line by A lined up with the red dot... through the viewfinder all i see is F-- under Av mode.
09-24-2009, 11:21 AM   #18
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QuoteOriginally posted by protocold Quote
Also it seems like the "A" doesnt lock nor do I have to press the A button to move into/out of "A" position.. is that abnormal?

On my A50/F2, I always have to press down the A button in order to move the aperture in "A" position...
The A button on the Vivitar behaves just like the one on the Pentax-A lens: you have to press the button to get into and out of A mode.

With the lens in A mode, auto exposure works fine on my K10D.

09-24-2009, 01:48 PM   #19
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It sounds like somebody has been in there, perhaps to remove the Ricoh pin (if the lens has PK-A/R on the aperture ring).

It now has two problems:

1/ The ball bearing for the 'A' button is missing (it may still be inside the mount stuck somewhere by it's own grease).

2/ The 'A' switch isn't working. It may need cleaning or it may be that the afore mention somebody has removed the 'A' contact instead of the Ricoh pin. If this is the case the Ricoh pin can be used to replace the 'A' contact.

I would disassemble and check.

Be careful not to lose the aperture detent ball bearing.

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09-25-2009, 08:43 AM   #20
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Thanks so much alfa75ts.

Ok, i took apart the lens as suggested, you are right that

1/ The ball bearing for the 'A' button is missing.

But i suppose that will only affect the locking functionality.. it isnt a show stopper I suppose?!??!

As for the A pin, it is there like what you shown.

Actually how does the A switch work? I am guessing that when the aperture ring turn into "A", a small tiny screw on the ring itself would push the copper on the "A" switch onto the contact below? I am kinda confused.
09-25-2009, 09:05 AM   #21
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QuoteOriginally posted by protocold Quote

Actually how does the A switch work? I am guessing that when the aperture ring turn into "A", a small tiny screw on the ring itself would push the copper on the "A" switch onto the contact below? I am kinda confused.
when you rotate the aperture ring to the A position, the springy contact shown i the photo touches a contact to connect the A pin to the lens mount base.

If you get desperate, you can make this connection perminant, because all the A pin does electrically is connect the A pin to the lens mount
09-25-2009, 12:29 PM   #22
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QuoteOriginally posted by protocold Quote
I am guessing that when the aperture ring turn into "A", a small tiny screw on the ring itself would push the copper on the "A" switch onto the contact below? I am kinda confused.
Got it in one! The screw is on the opposite side of the aperture ring to the button, you should see the head on the outside and the thread penetrates about 2mm inside.

QuoteOriginally posted by protocold Quote
But i suppose that will only affect the locking functionality.. it isnt a show stopper I suppose?!??!
Another winner! Another thing to make sure of if you find a replacement ball bearing is that the 'tab' on the button sticks up as in the pic (but this may jam the lock without a ball bearing (just guessing here)).
09-26-2009, 10:43 PM   #23
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It is the contact... perhaps the "A" pin was worn over the years that it no longer touches the connection point on the body.

I end up using soldering gun to put a tiny bit of solder on the pin and now it seems to fix the A problem. Thank you everyone.

But damn it... I lost the small bearing on the aperture ring.... does anyone know where I can find such small bead or is there any other alternative that I can use as substitute?


Last edited by protocold; 09-27-2009 at 08:35 AM.
10-10-2009, 08:33 AM   #24
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I've finally figure out how to put everything back together, except the last step, I wasnt sure how to correctly adjust the front lens element, which is separated from the rest of the lens by a metallic spring like ring. Can someone shed some light on this? Thanks.
10-10-2009, 01:27 PM   #25
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G'Day Jackson,

See here and here for the method I used.

However, if your camera gives the 'focus lock' beep you could set the lens at infinity and tape it so it won't move, point the camera at a distant object (say the rim of the moon) and adjust the front element until you get the beep. Then try taping the front element and adjusting the focus normally to check.

I haven't tried the second method but I think it should work.
10-10-2009, 10:12 PM   #26
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QuoteOriginally posted by alfa75ts Quote
G'Day Jackson,

See here and here for the method I used.

However, if your camera gives the 'focus lock' beep you could set the lens at infinity and tape it so it won't move, point the camera at a distant object (say the rim of the moon) and adjust the front element until you get the beep. Then try taping the front element and adjusting the focus normally to check.

I haven't tried the second method but I think it should work.
Thank you so much. I do have the beep.

One more question... should I put the lens in 105mm or 28mm and then adjust infinity? Because I currently put it as 105mm and got the beep, however when I adjust to 28mm, I dont get the focus... is it a desirable behavior?
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