Stacking Kenko Extension Tubes

[purplehaze]

Does anyone else lose CPU function when using the full set of Kenkos? I am having trouble using the full stack on my D7100 plus Nikkor 105 mm macro, especially with two RC200s attached to the front of the lens and am wondering whether the weight is stressing the contacts. I have been attaching each ring and the lens carefully and making sure they click. I don't mind losing autofocus so much, but I am unable to keep the mirror up to focus with LiveView. I used to use the full set regularly on my D90 and don't recall ever having had this problem before. Each of the tubes individually seems to work fine with my macro, as does any combination of two. I have the 12-20-36 mm DG set. Suggestions welcome.

[Stagecoach]

Janis,

This is a very well documented problem when stacking the Kenkos especially if you add the weight of the SB200s. You only have to look at the rig and you can see the distortion between the mating flanges.

The solution if using a tripod is to purchase a cheap macro rail and you can then support the lens to the rail, I now use a short length of pencil for this as it exactly the right diameter.

If hand-holding, good support of the camera and lens is required.

There appears a weakness in the tubes design in that there is movement between the contacts and I undertook a mod on mine that has appeared to assist greatly.

Grahame

[purplehaze]

Oh, thank you, Grahame. I have a rail and so I will give that a try! I fear my hands are not large enough to provide good support for hand-holding, so I will have to work around that limitation.

[purplehaze]

FYI - A full roll of Hartz doggie bags fits nicely under the lens at the end of the rail and closes the gap between the flanges. (You were right about it being visible.) Thanks again, Grahame.