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Comment by aftonandpaul posted on Help needed with Vivitar Auto Extension tubes at 01/03/2012 - 13:43
Comment by aftonandpaul posted on Macro tubes, idiot guide please at 01/03/2012 - 13:40
Hi again, after playing for a while, I can confirm that stop down metering is working with my Tokina 28-105mm lens, which is fine, and I've managed to take a few interesting shots.
Shame I cant really use my DA L lenses with this, since they lack the aperture ring. The AT-23 version of these tubes would be great to play with, but I am satisfied to play with these AT-22 tubes for now.
Thanks for your help
Comment by aftonandpaul posted on Help needed with Vivitar Auto Extension tubes at 01/03/2012 - 13:15
I'm going to have a play with the kit again this evening, and see if I can learn more, and then report back.
Comment by aftonandpaul posted on Help needed with Vivitar Auto Extension tubes at 24/02/2012 - 10:56
I feel my problem is that I need
1) Electrical contact through the tube for the 7th contact as shown in the link (done)
2) I also need the 3rd body contact depressed, so that the camera is happy to issue aperture commands to the lens via the tube aperture levers. The Jessops tube referred to here have a ball contact to do this, but the vivtar tubes have none.
It's point 2) where these tubes seem to be failing, so what do I need, a thin ring with a nobble in the right place to depress the 3rd contact, that fits between tube and camera body?
Comment by aftonandpaul posted on Macro tubes, idiot guide please at 23/02/2012 - 11:19
Your image is very useful, I have done something very similar, but have extended my emery work down a little further, to where the lug (at 3'o clock position) starts.
Despite this, I cant get the thing to work as expected.
So, just to check I'm not being dense, here is my sitation:
Pentax K-r, DA L 18-55mm Kit lens, Vivitar AT-22 extension tube set
When the extension tube is connected, the aperture of the lens remains fully open at all times, either when doing optical preview with the Green button, or when taking a photo. The aperture indicator reads F -.-
Removing the black layer as you have done would allow electrical contact with all camera body contacts (it seems this is important as the 1st contact appears to require contact).
However, this does not work for the 5th contact (working clockwise from 6'o clock position on the body). This 5th contact is recessed, and requires a convex contact from the lens to tell the camera that aperture settings may be controlled automatically. As you know, while most lenses will have such a contact, the extension tubes have not, and I feel this is the problem.
This idea is supported by the fact that I see the exact same behaviour if I attach a lens with an aperture ring set to anything other than 'A', (this retracts the lens contact from the 5th position). This suggests to me that when the tubes are attached, the 'A' contact on the body is not engaged. And consequently I have no aperture control.
So am I expecting to much here? Do you have control of your aperture with your setup? or do you make do with full open aperture?
Apologies for long post
Thanks
Comment by aftonandpaul posted on Help needed with Vivitar Auto Extension tubes at 23/02/2012 - 11:09
Been removing paint from my extension tubes in order to fix this problem, but even after removing paint, I still have the problem.
The pictures above are no longer available, could anyone re-upload the pictures to show where paint must be removed from?
Thanks
Comment by aftonandpaul posted on Macro tubes, idiot guide please at 22/02/2012 - 14:30
Saw this thread and a few others suggesting removing the black coating around the area which contacts with the electrical contacts on the camera body. However, the problem remains.
Could anyone post a picture of their tubes showing the places where the black coating has been removed?
THanks
Paul
Comment by aftonandpaul posted on Help needed with Vivitar Auto Extension tubes at 22/02/2012 - 13:48
Would you accept an offer of 300 + delivery?
Thanks
cant receive PMs so email at aftonandpaul (at) gmail dot com
Comment by aftonandpaul posted on For Sale: Pentax K-r Black & 18-55mm lens + 8GB SDHC at 28/01/2012 - 22:38
Comment by aftonandpaul posted on For Sale: Pentax K-r Black & 18-55mm lens + 8GB SDHC at 25/01/2012 - 21:32


Happy Snapping
Paul