Kenko AF extension tubes

[KenJ8246]

Anyone who has used these otherwise good tubes should be familiar with what I'll call 'slop' in the connections.  Depending on the size and weight of the lens out front, I've experienced intermittent loss of electrical contact from the camera to the lens.

My question: is it possible to take some or all of that slop out of the connection either through machining or some oher intervention?  Roy?

I miss being able to alter aperture in thirds of a stop.

[DigitalScape]

I have not heard of any issues with the Kenko tubes that causes connections issues.  I assume that you have tried cleaning the contacts.  Are you seeing/feeling any wobble in the connection, or does everything feel tight?

[motleypixel]

Can you post a video detailing what you are experiencing?  You have a D300s now   Interesting...don't use my Kenko's much anymore but generally didn't stack them, just used the 36mm one with the 100/2.8.  Machining?  Possibly, but it depends...you may actually need to add a shimming material instead of removing material.

[KenJ8246]

With the entire set, 36, 20 and 12mm tubes in place, I've had intermittent loss of electrical contact with a Nikkor 105mm f2.8 and a Sigma 150.  I realize the Sigma was a lot of weight and that using all the tubes is asking for trouble but I've not had this problem with Nikon tubes.  Granted, the Nikon tubes are non-auto--no electrical contacts--but their connections are tighter with no give.  I seldom shoot with more than one tube now---don't like the light loss.

It was a thought...

[motleypixel]

The tolerances of the Kenkos are probably not as tight as the Nikon ones.  I would say maybe inspect the bayonet tabs and see if you can bend any of them to make the bayonet tighter.

[KenJ8246]

...inspect the bayonet tabs and see if you can bend any of them to make the bayonet tighter.

Gonna show my ignorance:  bayonet tabs?

[motleypixel]

Oh well, it's how the male (lens side) becomes attached when "screwed" into the female (camera side).  On the lens-side or in this case the ext. tubes, you may be able to flex-out or bend out the baronet surfaces such that there's more bite on the female side.  If you could give a lens a dose of Viagra I suppose it may help

[DigitalScape]

If you could give a lens a dose of Viagra I suppose it may help

 
   
Then you would limit Kenny's shooting time to 4 hours.   

[KenJ8246]

If you could give a lens a dose of Viagra I suppose it may help

 
   
Then you would limit Kenny's shooting time to 4 hours.   

If I ain't got any keepers after 4 hours, shame on me.  Besides, in the summers, after 4 hours of shooting, I'm soaked to my knees with sweat by then anyway.