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03-24-2014, 12:13 PM   #1
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vivitar teleconverter - rounded Ricoh pin

Hi Guys,

I'm hoping someone will be able to answer a quick question. I've read about various forum members using a de-glassed teleconverter as a auto macro tube (when I say auto I refer to apetrture contol only). I've purchased a verh cheap Vivitar Telex2 and have removed the glass internals. I'm well aware of the Ricoh pin problem and I'm pretty sure this device has one. However I think I read that if its a rounded pin then it does not need to be removed? Can anyone verify if this is the case and also if I'm correct in saying this is the rounded pin??

So the question is, do I need to conduct more surgery on this Teleconverter before I attach to my K5??








03-24-2014, 12:18 PM   #2
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It looks like the safe version to me, but since you're modifying it anyway it wouldn't hurt to remove it for peace of mind.
03-24-2014, 12:21 PM   #3
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Press it with your finger -- it should be spring-loaded and move, right? Shouldn't give you any trouble.
03-24-2014, 12:24 PM   #4
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Yes, it is a rounded pin and yes, it is probably harmless, though I would caution that if you have a problem it is not my fault.


Steve

(...have one lens with a rounded pin and use it with no problems, but it is not the OP's lens...)

03-24-2014, 01:13 PM   #5
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Ok on the recommendations from everyone I have completed the removal of the pin (pleased to say it was fairly simple). Everything seems to be good, lens attaches and removes and Aperture control works J

A few odd things but perhaps this is normal. ‘Im using a Sigma 17-70mm 2.8. With the Teleconverter attached my camera now allows me to go to F1.2. I can not focus at all until I get approx 20-30cm from object (but I can now get ridiculously close and still focus). I'm assuming all of this is normal and expected when using a de-glassed Teleconverter??
03-24-2014, 01:22 PM   #6
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The contacts aren't all passing through from the lens correctly or isn't reading them at all (f/1.2 might be the default) so it can tell there is an 'A' lens but it has the aperture range wrong.

See here:

http://www.robertstech.com/matrix.htm
03-24-2014, 02:18 PM   #7
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I get the same results with a Sigma lens (70/2.8 macro) on an A-type TC. I think it's the lack of the data contact that is the issue.

(BTW, I've converted several of these KR-type TCs to use as extension tubes. I don't think it's necessary to remove the Ricoh pin but I did anyway.)
03-24-2014, 04:25 PM   #8
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QuoteOriginally posted by vonBaloney Quote
The contacts aren't all passing through from the lens correctly or isn't reading them at all
What he said.

OTOH, the Sigma is not a constant max aperture lens and it may be that the data pin is used for all communication. A little test walk with a continuity tester (ohmmeter) will tell what the pin-outs are for the lens and whether they are being transmitted through the TC.


Steve

03-24-2014, 04:31 PM   #9
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Actually this is probably the same problem other extension tubes have with Sigma lenses -- it is the black non-conductive surface. Did some research into that a while back.
03-24-2014, 04:54 PM   #10
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QuoteOriginally posted by vonBaloney Quote
it is the black non-conductive surface
Same issue with non-anodized mounts -- I think Sigma lenses require the data contact to work correctly.
03-24-2014, 04:55 PM   #11
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Put a Pentax lens on it and I bet it reads correctly?
03-24-2014, 06:40 PM   #12
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I'll take your word for it but the only Pentax lens I have is FA43 and Im not sure if I want to attach my prized FA lens on this Teleconverter :-)

I can see the Sigma contacts dont match the Teleconverter so it make sense now and I can live with the odd F stop numbering. The Sigma 17:70 is the closest I have to a macro lens so I was always planning to use this lens.

QuoteOriginally posted by vonBaloney Quote
Put a Pentax lens on it and I bet it reads correctly?

Cheers for all the advice everyone. Much apprechiated.
03-24-2014, 07:12 PM   #13
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QuoteOriginally posted by mde1970 Quote
I'll take your word for it but the only Pentax lens I have is FA43 and Im not sure if I want to attach my prized FA lens on this Teleconverter :-)

I can see the Sigma contacts dont match the Teleconverter so it make sense now and I can live with the odd F stop numbering. The Sigma 17:70 is the closest I have to a macro lens so I was always planning to use this lens.




Cheers for all the advice everyone. Much apprechiated.
The TC won't hurt your FA in any way, why would it?

And the contacts aren't supposed to "match", they are simply a full set of them just like on the camera body -- that's the point of it, to essentially just move the mount on the body outward so all the contacts on the TC are one-to-one matched with the body mount and so mounting a lens on the TC should behave just as the same as mounting it directly to the body. Then the lens uses the contacts that it happens to have as normal. But some third-party lenses don't seem to work without a bare metal mount (the part with no contacts) also conducting with the lens. (i.e. it wants the black part on side of the TC that mounts to the lens to be bare metal) And so if you were to sand down the black to bare metal, or simply put a piece of conductive foil tape on the mount (which adds more friction, making it tougher to mount a lens) then it would work as it should on your Sigma.
03-25-2014, 05:18 AM   #14
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QuoteOriginally posted by vonBaloney Quote
then it would work as it should on your Sigma
Again, in my experience, it won't. I've tried the Sigma 70/2.8 on TCs with shiny metal mounts; same result.

mde1970, you might find it worthwhile to do some testing at various aperture settings to find out what f-stop you're actually getting. In my experience it is not a consistent translation. As I recall, f/1.2 on the camera did not result in the lens staying wide open, and a change of a full stop on the camera did not necessarily result in the same change at the lens -- sometimes yes, but other times no change, or a smaller or greater change.
03-25-2014, 05:27 AM   #15
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QuoteOriginally posted by baro-nite Quote
Again, in my experience, it won't. I've tried the Sigma 70/2.8 on TCs with shiny metal mounts; same result.
I am basing this on my own experience getting the very same Sigma 70 (and another Sigma) to work properly. There is a thread somewhere about the whole affair. I also got it to work by blocking areas in-between contacts. It might need a conducting bridge all the way back to the body (which was solved by putting tape on the outside of the TC running from mount to mount. It CAN be gotten to work, one way or another...
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