lens A- setting iffy.

dh4412 · 03-24-2012, 05:04 PM

i have an exakta 24mm lens, ( when i first got it i took the ricoh pin out , and think i did it correctly ? ) , the lens works fine using the aperture ring settings on its own, but it's an A lens, so wanted to use it as that, sometimes it will work if set on ' A ' and sometimes not, but it will work if i hold the ring over onto the A setting with some pressure ; as soon as i take the pressure off, i get the F - - icon; ( but you may or may not know, that is a pain ) , any ideas as to what is going on with it? can it be fixed or is it just broken ? thanks.

Adam · 03-24-2012, 05:32 PM

Sounds like the aperture ring is loose and/or misaligned. You may be able to fix this by taking it off and checking it - if you know how to do that, I'd give it a shot as there isn't much to lose

dh4412 · 03-25-2012, 06:58 AM

adam, i backed off the only screw i found on the ring, and re-tightened , seems to be showing me the aperture setting now, i'll keep my fingers crossed. thanks.

**RKKS08** · 03-28-2012, 10:42 AM

If the lens had a Ricoh pin and an "A" setting, it may be the Ricoh version of the KA bajonet.

This would not be compatible with the original Pentax KA bajonet. Ricoh used their own system for aperture control from the body. You can use the "A" setting only with Ricoh film bodies. All other modes should work as with Pentax lenses.

dh4412 · 03-28-2012, 12:06 PM

yeah, not sure what is going on with this lens, now the focus ring is working sometimes, sometimes not; gets stuck and won't move, then it will.... probably just have to chalk this up to a bad investment i guess

**RKKS08** · 03-28-2012, 05:14 PM

Maybe I should have explained the problem more in detail.

With Pentax KA lenses, one of the electrical contacts (I think it's #8) signals the body that the lens is in "A" mode. With Ricoh "KA" lenses, the "Ricoh pin" is doing this instead.

Some 3rd party lenses supported only one of the systems, some others were built for dual use. If the Exakta was designed for dual use, it must have the electric contact as well as the pin. If this is the case, is it possible you "removed" the pin in a way you may have damaged the electrical path to the contact as well?

EDIT:
I am not sure, but I think with Pentax the contact is electrically connected with the lens mount when not set "A", and disconnected if it is in "A" position. But you can find this out using another lens and measuring the resistance. You will also find this information in many threads in this forum (but it may take some time to find these threads).

EDIT:
Use the search function of this forum and search for "Ricoh mode".

dh4412 · 03-29-2012, 06:05 AM

thanks rk, i did get the lens to work in A; at least for one session, not sure if it will stay that way; but then as i mentioned, the manual focus ring just got stuck and wouldn't move, then it would, then it wouldn't. i may see if i can fix that somehow, other than that .. kinda dissapointing. but i will check the ricoh mode thread you suggest.

03-24-2012, 05:04 PM	#1
dh4412 Senior Member Join Date: Feb 2011 Location: connecticut Photos: Gallery Posts: 248	lens A- setting iffy. i have an exakta 24mm lens, ( when i first got it i took the ricoh pin out , and think i did it correctly ? ) , the lens works fine using the aperture ring settings on its own, but it's an A lens, so wanted to use it as that, sometimes it will work if set on ' A ' and sometimes not, but it will work if i hold the ring over onto the A setting with some pressure ; as soon as i take the pressure off, i get the F - - icon; ( but you may or may not know, that is a pain ) , any ideas as to what is going on with it? can it be fixed or is it just broken ? thanks.

03-24-2012, 05:32 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,608	Sounds like the aperture ring is loose and/or misaligned. You may be able to fix this by taking it off and checking it - if you know how to do that, I'd give it a shot as there isn't much to lose Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-28-2012, 05:14 PM	#6
RKKS08 Site Supporter Join Date: Mar 2010 Location: Frankfurt am Main Posts: 1,241	Maybe I should have explained the problem more in detail. With Pentax KA lenses, one of the electrical contacts (I think it's #8) signals the body that the lens is in "A" mode. With Ricoh "KA" lenses, the "Ricoh pin" is doing this instead. Some 3rd party lenses supported only one of the systems, some others were built for dual use. If the Exakta was designed for dual use, it must have the electric contact as well as the pin. If this is the case, is it possible you "removed" the pin in a way you may have damaged the electrical path to the contact as well? EDIT: I am not sure, but I think with Pentax the contact is electrically connected with the lens mount when not set "A", and disconnected if it is in "A" position. But you can find this out using another lens and measuring the resistance. You will also find this information in many threads in this forum (but it may take some time to find these threads). EDIT: Use the search function of this forum and search for "Ricoh mode". Last edited by RKKS08; 03-28-2012 at 05:28 PM.

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03-25-2012, 06:58 AM	#3
dh4412 Senior Member Join Date: Feb 2011 Location: connecticut Photos: Gallery Posts: 248 Original Poster	adam, i backed off the only screw i found on the ring, and re-tightened , seems to be showing me the aperture setting now, i'll keep my fingers crossed. thanks.

03-28-2012, 10:42 AM	#4
RKKS08 Site Supporter Join Date: Mar 2010 Location: Frankfurt am Main Posts: 1,241	If the lens had a Ricoh pin and an "A" setting, it may be the Ricoh version of the KA bajonet. This would not be compatible with the original Pentax KA bajonet. Ricoh used their own system for aperture control from the body. You can use the "A" setting only with Ricoh film bodies. All other modes should work as with Pentax lenses.

03-28-2012, 12:06 PM	#5
dh4412 Senior Member Join Date: Feb 2011 Location: connecticut Photos: Gallery Posts: 248 Original Poster	yeah, not sure what is going on with this lens, now the focus ring is working sometimes, sometimes not; gets stuck and won't move, then it will.... probably just have to chalk this up to a bad investment i guess

03-29-2012, 06:05 AM	#7
dh4412 Senior Member Join Date: Feb 2011 Location: connecticut Photos: Gallery Posts: 248 Original Poster	thanks rk, i did get the lens to work in A; at least for one session, not sure if it will stay that way; but then as i mentioned, the manual focus ring just got stuck and wouldn't move, then it would, then it wouldn't. i may see if i can fix that somehow, other than that .. kinda dissapointing. but i will check the ricoh mode thread you suggest.