kenko exention tubes

[stuart wanuck]

would appreciate any discussion on the use of kenko extenders with nikon 500 mm lens to enable to use closer distance focusing as well as ability to use full 5oo mm length.any problems with optics or lens use?

[Alan Lillich]

I've used Kenko tubes with my 500 f/4 P and some newer AFS lenses. Extension tubes have noting inside but air, so there is no optical loss, nothing for the rear lens element to bump into. I've never had any electronics trouble using a single tube, seldom with 2 tubes, moderately often with 3 tubes. I own the 3 tube 12/20/36 mm set. There is enough play in the tube to tube union that the weight of a D300 or D700 can flex it and cause a loss of electrical contact. Careful support of the body solves the problem when it happens. When contact is good AF and metering are fine.

[Chris Ober]

You'll lose the ability to focus at infinity with them and depending on the lens used, you could see some light fall-off. I don't think there will be any with a 500 but you could probably notice if you used them with wider lenses.


Moving this to the photography gear forum.