Disappointed in Kenko DG extension tubes for canon

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geetee50
Posts: 91
Joined: Tue Mar 06, 2012 1:23 pm

cantilever spring

Post by geetee50 »

Superb! I never gave it a thought that I could tighten my tubes, very easy to do too!

I used a metal tooth pick and just moved the sprung cantilever out by it's own thickness about half way down it's length, there are four on each tube i see. Very snug fit now so should hold the larger lens with no problem. I see Riks are the same as mine but the other set of pics seem to be lined with felt, are these quite old Phil? Mine are a year old and now set the same as these.

DQE
Posts: 1653
Joined: Tue Jul 08, 2008 1:33 pm
Location: near Portland, Maine, USA

Re: cantilever spring

Post by DQE »

geetee50 wrote:Superb! I never gave it a thought that I could tighten my tubes, very easy to do too!

I used a metal tooth pick and just moved the sprung cantilever out by it's own thickness about half way down it's length, there are four on each tube i see. Very snug fit now so should hold the larger lens with no problem. I see Riks are the same as mine but the other set of pics seem to be lined with felt, are these quite old Phil? Mine are a year old and now set the same as these.
Re the age of my Canon felt/flocking lined tubes: they were acquired in about 2006. I'm about 90% certain that this is the correct year but it could be off by as much as a year.

I'm also about 90% certain that they were bought new from bhphotovideo.com, so I believe they aren't counterfeit or whatever.
-Phil

"Diffraction never sleeps"

Craig Gerard
Posts: 2877
Joined: Sat May 01, 2010 1:51 am
Location: Australia

Post by Craig Gerard »

*Only noticed there was another page to this thread after posting my latest response (below).

Charlie,

After further thought since posting I came to a similar conclusion, but not as detailed as your summary. Thanks for lending your experience.

The main area which concerns me is when I have a Canon DSLR attached to Nikon tubes or bellows, there is 2-3mm of 'play' at the camera end which translates to a significant change in the FOV, not to mention potential for vibration. The problem is also present when using other brand attachments. This issue has concerned and annoyed me for some time.

I'll further adjust the internal tensioning springs of the adapters; I've most likely been too conservative, failing that, I've heard good things from different sources about a Novoflex adapter (horrendously expensive); but if this is one problem that can be solved by throwing some money at it, I feel the expense is justified.

Kipon appear to have a clone 'Kipon N/G-EOS' of the Novoflex 'EOS/NIK-NT' that may also be worth considering. These adapters were designed to offer manual aperture control of Nikon 'G' lenses on EOS cameras. I'll most likely end up with both adapters :roll:

I've been using a good 'Made in Japan' Nikon F, T-mount adapter in my tube lens assembly, but even here there is some minor play in the bayonet connection, most of which could be addressed using various methods. Kipon claim to have a T-mount with no "play", so I've ordered one to have a look.


Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

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