13
\$\begingroup\$

Given lighting is not a problem, can you hit a limit where you have too much extension tubes (a very long tube) and the quality of the image will suffer? For example a diffraction limit will be hit for the adjusted F-Stop or something like that?

What are the variables that come into play here.

Improve this question
\$\endgroup\$

1 Answer 1

Reset to default
11
\$\begingroup\$

Yes, if I put 68 mm of tube (36+20+12) behind my 12-24 lens, I can't focus on a subject because the focus point is behind the front lens.

Improve this answer
\$\endgroup\$
3
  • \$\begingroup\$ Can you explain the three numbers? \$\endgroup\$
    – Reid
    Commented Jul 19, 2010 at 16:26
  • 1
    \$\begingroup\$ @Reid: I have a kit with three extension tubes, one 36 mm one 20 mm and one 12 mm. \$\endgroup\$
    – Guffa
    Commented Jul 19, 2010 at 16:44
  • \$\begingroup\$ Oh, OK. I thought that you were presenting a computed answer (i.e., 68mm was theoretically significant somehow), but instead you're relating a personal experience. Thanks for the clarification. \$\endgroup\$
    – Reid
    Commented Jul 19, 2010 at 17:01

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.