Nikon D800 and Kenko Extension Tubes

[Stagecoach]

I'm presently having problems with signal continuity when using some of my Kenko extension tubes on my D800 and wonder if anyone has specific experience of using the Kenko 10, 20,36 mm AF set with a D800.

Scenario;

The 20mm tube works perfectly on both D300 and D800, AF/VR/aperture readout all fine.

The 36mm tube works perfectly on the D300 , AF/VR/aperture readout all fine.

The 36mm tube does not work on the D800, No AF, No VR No aperture readout.

All contacts on cameras and tubes visually look ok and have been cleaned and worked.

Having undertaken numerous tests I am starting to come to the conclusion that perhaps there are minor manufacturing tolerance differences between camera mounts OR the D800 is having trouble with perhaps a higher resistance of the contact internals due to age.

Anyway, is anyone using a Kenko set with a D800 successfully?

Grahame

[Dave Humphries]

Have you tried the 10 + 20 in tandem on D800 Grahame?
That would have more resistance and may also not work.

However, assuming it does work ...

Might even be worth trying the 10 + 36 and 36 + 10 variations to see if you could narrow down which end the tolerance issue might be (e.g. camera or lens end); I guess there's just a chance with 10 next to camera followed by 36, then lens, it might work.

Clutching at straws, I know.

is anyone using a Kenko set with a D800 successfully?

Sorry - I don't have the precise experience you are looking for, nor the kit to test it out.

Dave

[Stagecoach]

Thanks Dave,

Yes I have tried the 10 + 20 in tandem, on the D300 fine, on the D800 intermittent

Further tests with the 36mm are now on hold until such time as I can put those 7 tiny springs and 7 tiny pins back in the holder, and fit it all together. A task not helped by her indoors not understanding the unpleasant language I have to use each time a spring goes for a jump

[IzzieK]

Maybe mine is different but all my extension tubes work on my D810 which is not really far off from your D800. I bought my extension tubes when I had my D800e and they worked very well without any problems at all. Can you still complain to the manufacturer or at least where you bought the set? I do not think you should have any problems at all. Mine also works with my D300s and D90. Have not have any problem with them.

[Stagecoach]

Hi Izzie,

I have had this set for over ten years now and used them a fair bit and that along with the susceptibility to oxidation of connections in this climate I can't moan really.

What make are yours?

[William W]

Hi Grahame,

I've been reading the thread since your OP. I have the same set of Kenko (for Canon though). I bought mine in 2004 when we crossed over to Canon DSLR. I don't use mine much. Mine work OK on all bodies even stacked in three.

. . . I have had this set for over ten years now and used them a fair bit and that along with the susceptibility to oxidation of connections in this climate I can't moan really.

That's what I am thinking too. They are worn out. It happens.

But you have all the remainder of Sunday to catch those little jumping buggers . . . good luck!

WW

[DanK]

My set of Kenkos eventually wore out. Specifically, it was the 36mm that finally went. It originally showed up as an intermittent loss of contact when I used it with an old body, and I assumed the problem was dirty or worn contacts on the body. Eventually, however, it happened on a new body. Cleaning didn't work. Since you can't buy them individually, I had to buy a new set, and I have had no problems since.

My suspicion is that the problem is tolerances that are made looser over time because of the weight of the lens. If that is the case, pulling the contacts slightly in the direction of the body might work. I didn't try it.

[Stagecoach]

But you have all the remainder of Sunday to catch those little jumping buggers . . . good luck!

But the only thing I successfully achieved by the end of Sunday Bill was that I had not lost any of those jumping buggers, they are still not fitted back where they belong

I will not give up, I will not give up, I will not give up........................................

[Stagecoach]

My set of Kenkos eventually wore out. Specifically, it was the 36mm that finally went. It originally showed up as an intermittent loss of contact when I used it with an old body, and I assumed the problem was dirty or worn contacts on the body. Eventually, however, it happened on a new body. Cleaning didn't work. Since you can't buy them individually, I had to buy a new set, and I have had no problems since.

Good in a way to know I'm not the only one to have similar problems.

My suspicion is that the problem is tolerances that are made looser over time because of the weight of the lens. If that is the case, pulling the contacts slightly in the direction of the body might work. I didn't try it.

Another thing here Dan is that for each of the tubes 7 pins there are 4 separate signal transfer points that rely totally upon surface contact pressure for continuity. Perhaps one precaution may be to not store the tubes connected together causing the springs to be permanently compressed.

[William W]

. . . Another thing here Dan is that for each of the tubes 7 pins there are 4 separate signal transfer points that rely totally upon surface contact pressure for continuity. Perhaps one precaution may be to not store the tubes connected together causing the springs to be permanently compressed.

Which of course, is how I store mine.

Thanks for the heads up!

WW

[DanK]

Another thing here Dan is that for each of the tubes 7 pins there are 4 separate signal transfer points that rely totally upon surface contact pressure for continuity. Perhaps one precaution may be to not store the tubes connected together causing the springs to be permanently compressed.

Very good suggestion. Thanks. that's how I have been storing them.

[Stagecoach]

Good news, all three are now working, singly and stacked, on both cameras and nothing intermittent (yet). So I'll share my diagnosis and conclusions.

Some time ago I tackled the contact end (not the sprung pins) on the 36mm and it had been ok up until recently. Whilst wear could possibly have been a problem there was nothing to suggest it, e.g, no noticeable marking on the surfaces that the sprung pins come up against. Springs on the pins could have been deformed but considering the travel and that they were all out an equal length to the stops unlikely.

So, starting at the easy end............................

Fig 1

The lug contact faces press up against the 'doubled over' ribbon cable and are held in position by the 'clamping plate' shown in Fig 2. The lug faces can be cleaned.

Fig 2

Removal of the clamping plate allows cleaning of the ribbon cable contact faces.


Now the hard end...........................................
I would not recommend anyone stripping this down unless they have very good patience and are competent to undertake a continuity test to ensure no shorts are present between pins.

Fig 3

Fig 3 shows the 'pin' end assembly with the pin retaining block removed. The springs under the pins make contact with the tinned ends of the ribbon cable.

Fig 4

Fig 4 shows the pins and springs in their mounting block which on reassembly have to be aligned with the slight plastic dimple at the ends of the ribbon cable.

Rather than strip the 'pin' end down (Fig 3 & 4) simply turning the pins a few times (I used what I was told were eyelash tweezers) would no doubt disturb the contact faces enough to clean them.

Grahame

PS. I forgot the conclusion................ not determined !

[IzzieK]

I have both the Kenko and the Vello brands which I switch from one to the other depending on which bag I came to discover first so maybe mine might not go too early yet. I think yours is suffering from old age... Sell it to the museum so you can make even just a little bit of money before you finally get rid of it. Then buy another set to replace it.

Hi Izzie,

I have had this set for over ten years now and used them a fair bit and that along with the susceptibility to oxidation of connections in this climate I can't moan really.

What make are yours?

[IzzieK]

Rather than strip the 'pin' end down (Fig 3 & 4) simply turning the pins a few times (I used what I was told were eyelash tweezers) would no doubt disturb the contact faces enough to clean them.

Eyelash tweezers! Who would want to remove their eyelashes? Women add eyeslashes on top of one another (I don't!!!) Maybe that is what it is use for, come to think of it...but I have not heard of that before, but I have about two or three eyebrow tweezers...and worst comes to worst, the long tweezers that came with my overlocker.

Thanks for the process, I am good with fiddling with smaller stuffs so if I come upon a problem like yours might be able to use the information. I have patience..I have patience...I have patience...

[William W]

Thanks Grahame, I am sending mine over by express post for a clean and service!

Seriously though, thanks for he details and pictures of the strip-down, I have kept it for reference.

WW

[Stagecoach]

Hi Izzie,

Eyebrow, that's it

I must of misheard when I was confronted with "What are you doing with my eyebrow tweezers"

[IzzieK]

Hi Izzie,

Eyebrow, that's it

I must of misheard when I was confronted with "What are you doing with my eyebrow tweezers"

Thanks for this post, now I have to separate mine and sew up little bags for each of my extensions...one more job to do...but it'll be worth it to the one who will inherit my camera and its accessories...

[ST1]

Thanks for this post, now I have to separate mine and sew up little bags for each of my extensions...one more job to do...but it'll be worth it to the one who will inherit my camera and its accessories...

Hi Izzie, how about sowing up two sets so you could send me a set for Christmas

[IzzieK]

Hi Izzie, how about sowing up two sets so you could send me a set for Christmas

Or you can go to a nearest craft/wedding store and buy yourself one of those flavour bags that bride and grooms uses as either decorations on the wedding tables or giveaways. It will be cheaper than sending it by snail mail. They are usually sold by the dozens, I think...and it has a ribbon to tie each one shut.