Just received my Vivitar MC TC 2x PK-A. Need help.

[rparmar]

I have added a link to this thread from the definitive V2XMFTC thread.

[JMS]

Here are the instructions:

First, for all this to work, it has to be a PK-A mount TC, with all the contacts.

OK- get a small eyeglass-type Phillips screwdriver. Extend the helicoid all the way, and carefully remove the rear lensmount. Remove opposite screws first to balance the forces, and slowly remove the lensmount, taking the optical assembly with it, as the two are attached. As you can see, the contacts are small pins mounted on springs. To make life a bit easier, remove the contacts and seal them in a Ziploc bag until you need to put them back. Now, looking down into the body of the TC, you can see that the rear contacts are attached to the front contacts by springs. One or more may have come loose from its mounting, and needs to be reseated. Use a pair of tweezers to grab and reseat the end of the spring on its mount Do this for all the springs that need it, then close the TC back up. To close it up, place the pins in their holes in the lensmount, and then align it all. Make sure that the aperture actuator and reader levers are in the correct position- otherwise, you could damage a lens or camera that you mount it on.

That's it!

I will post pictures when I get a chance. Remember, if you want, you can send the TC to me, and I'll fix it for you.

Re: variable aperture zooms showing as a single aperture: this is normal behavior. Only a single aperture set can be transmitted via the "A" contacts. For AF zooms, the "actual" aperture data is transmitted via the digital contact- the same way focusing distance and focal length are transmitted.

[raider]

Thanks JMS. I will have a go at it.

[PentaxScott]

Originally Posted by JMS

Re: variable aperture zooms showing as a single aperture: this is normal behavior. Only a single aperture set can be transmitted via the "A" contacts. For AF zooms, the "actual" aperture data is transmitted via the digital contact- the same way focusing distance and focal length are transmitted.

That would explain why I only seem to get one f-stop number. Any particular reason though it reads f/1.2 on my 70-300 zoom lens? Is this something that could be solved by TC surgery?

[JMS]

Nope. Most likely, to cut costs, the Tamron ONLY has the digital contact. Thus, it shorts ALL the contacts, and thus produces the f1.2 signature.

[jerrymouse]

Originally Posted by JMS

Here are the instructions:

First, for all this to work, it has to be a PK-A mount TC, with all the contacts.

OK- get a small eyeglass-type Phillips screwdriver. Extend the helicoid all the way, and carefully remove the rear lensmount. Remove opposite screws first to balance the forces, and slowly remove the lensmount, taking the optical assembly with it, as the two are attached. As you can see, the contacts are small pins mounted on springs. To make life a bit easier, remove the contacts and seal them in a Ziploc bag until you need to put them back. Now, looking down into the body of the TC, you can see that the rear contacts are attached to the front contacts by springs. One or more may have come loose from its mounting, and needs to be reseated. Use a pair of tweezers to grab and reseat the end of the spring on its mount Do this for all the springs that need it, then close the TC back up. To close it up, place the pins in their holes in the lensmount, and then align it all. Make sure that the aperture actuator and reader levers are in the correct position- otherwise, you could damage a lens or camera that you mount it on.

That's it!

I will post pictures when I get a chance. Remember, if you want, you can send the TC to me, and I'll fix it for you.

Re: variable aperture zooms showing as a single aperture: this is normal behavior. Only a single aperture set can be transmitted via the "A" contacts. For AF zooms, the "actual" aperture data is transmitted via the digital contact- the same way focusing distance and focal length are transmitted.

First, I want to thank you. I thought I bought broken teleconverter, but I managed to fix it following your instructions.

Originally Posted by raider

Hmm...may I request some photos how to fix the broken pins? I am not too brave to conduct any surgery without proper knowledge.

Here are some images for you. The surgery is not hard, but make sure you don't lose the little pins :P

[Igilligan]

very helpful to the forum

[tootall]

Originally Posted by Igilligan

very helpful to the forum

100% Agree, answered my question and I now have a fixed MC7 in my hot hands