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07-24-2013, 01:34 AM   #1
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AE teleconverter works on K-01 but not other bodies?

SOLVED: Seems I just needed to remove some paint from the TC so the camera would be grounded per Fogel70's suggestion.

I purchased a used Vivitar 2x TC on ebay with AE contact points. It works just fine on my K-01 and ZX7, but I don't get auto exposure with it on my K5 IIs nor my *ist DS. Contacts were clean on all bodies, lenses, and the TC. Does anybody know why this could be happening?


Last edited by geomez; 07-25-2013 at 03:11 AM.
07-24-2013, 03:51 AM   #2
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What lenses are you using?
07-24-2013, 05:12 AM   #3
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QuoteOriginally posted by geomez Quote
I purchased a used Vivitar 2x TC on ebay with AE contact points. It works just fine on my K-01 and ZX7, but I don't get auto exposure with it on my K5 IIs nor my *ist DS. Contacts were clean on all bodies, lenses, and the TC. Does anybody know why this could be happening?
Lowell's question is a good one for us to know! It boils down to phase detect vs. contrast detect focus. The K-5 and DS use phase detect, which needs enough light to be able to find proper focus. If you've put a 2x TC on even an F4 lens, it becomes and F8 lens, which will not provide enough light for focus to be achieved (though it can vary from lens to lens and may work with some and not others in this specific example) If you're using the 100-300mm sigma lens in your signature, at 300mm the aperture is going to be beyond F11 wide open, definitely not enough light for the lens to focus.

The K-01 however uses contrast detect focus - this doesn't rely heavily on the wide-open aperture but on contrast in the image it is seeing - as long as there is contrast it will likely be able to find focus, which is likely why you're finding it will work with the K-01 but not the other 2 cameras. As to why it works with the film camera, that one is beyond me since it should be using some type of focus system similar to the K-5/DS - might just be that the old technology isn't as dependent on incoming light.
07-24-2013, 09:44 AM   #4
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I'd just like to point out that the OP is asking about Auto Exposure, not Auto Focus. And, Contrast AF and Phase Detect AF actually both measure contrast.

OP, check the Aperture Ring setting on all the (digital) cameras, maybe that's causing it.

07-24-2013, 10:45 AM   #5
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I deglassed the TC before using it. I tried it with the 40mm XS, and 18-55 kit, and a Tamron 90mm 2.8 macro with the aperture ring on "A". Same results with all lenses.
07-24-2013, 11:58 AM   #6
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QuoteOriginally posted by geomez Quote
with the aperture ring on "A"
I meant the setting in the camera. Maybe the TC isn't relaying the info for some reason.
07-24-2013, 01:09 PM   #7
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QuoteOriginally posted by Giklab Quote
I meant the setting in the camera. Maybe the TC isn't relaying the info for some reason.
The camera's are set to use lenses with an aperture ring.

My first guess is that the TC isn't relaying the info, which would mean a problem with the TC. But considering that it works with two cameras, I don't know what to think.
07-24-2013, 01:24 PM   #8
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QuoteOriginally posted by geomez Quote
My first guess is that the TC isn't relaying the info, which would mean a problem with the TC. But considering that it works with two cameras, I don't know what to think.
A similar problem frequently occurs with Tamron P/KA adapters from the 80's - they communicate aperture setting to and permit aperture selection from the body, but frequently only certain bodies in a users collection.

In that case the "fix" is to remove the very thin coating from the adapter by gently scraping the contacts themselve (or one of them - I can't remember which)

I would closely inspect the contacts on your TC to ensure nothing is interrupting electical connection between them and your non-working cameras.

As an owner of the K-01 I have noticed the K-mount is slightly different than on my other K-mount cameras - the width of the mount surface itself is a mm or two norrower than say my K10 or any of my film cameras. Maybe the contacts just barely line up on the two cameras working but are a hair off on the others.

07-24-2013, 01:38 PM   #9
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Does it work in LV on K5IIs? If it do, it might explain why it work on K-01.
Maybe the TC only fully support KAF or earlier mount,
07-24-2013, 02:19 PM   #10
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If the OP deglazed the TC maybe he damaged the aperture connections. He should take an ohm meter and check the connections straight through the converter
Likely one or more is open. Also if the TC has a np black base it needs to be sanded clean where pin 7 would normally be on AF lenses

A shot of the TC mounts would be useful
07-24-2013, 05:34 PM   #11
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The connection pins were not damaged when I removed the glass.

Attached are pictures of the connection points on the TC...

Attachment 181665

Attachment 181666

Last edited by geomez; 11-04-2015 at 03:07 PM.
07-24-2013, 06:50 PM   #12
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QuoteOriginally posted by Fogel70 Quote
Does it work in LV on K5IIs? If it do, it might explain why it work on K-01.
Maybe the TC only fully support KAF or earlier mount,
That seems to be the problem. It works on the K5IIs in live view but not though the viewfinder.

I've got a Focal branded TC that looks like it is exactly the model and manufacturer as this Vivitar TC but it works through the viewfinder. Odd.
07-24-2013, 11:21 PM - 1 Like   #13
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It's missing the seventh pin. And the anodized surface on the TC will isolate the it from ground on the camera.
If you follow Lowells instruction from above it should work.

Here's another thread on this matter.
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/89373-vivitar-...-no-issue.html
07-25-2013, 12:10 AM   #14
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QuoteOriginally posted by fogel70 Quote
it's missing the seventh pin. And the anodized surface on the tc will isolate the it from ground on the camera.
If you follow lowells instruction from above it should work.

Here's another thread on this matter.
https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/89373-vivitar-...-no-issue.html
Thank you!
07-25-2013, 03:13 AM   #15
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Does anybody know if there was a technical reason for Vivitar to anodize the mount, or was it just esthetic?
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