Join for FREE
It only takes a minute!
||Thread Tools||Rate Thread|
|Friday 11th January 2019, 23:46||#1|
Join Date: Jul 2008
Location: Gloucestershire UK
Prime focus - why the need for an extension tube?
Hello, I am just setting up to try prime focus digiscoping (Acuter 20-60x80 scope, Canon eos760D). I intend to use a 2x (possibly 3x) Barlow. Whilst looking at the equipment used for some of the prime focused, digiscoped pics shown in various user galleries here I see that most have included an extension tube (often 2"). I am assuming that this is placed between the Barlow and the camera. Can anyone clue me up on the following:-
A)What is the purpose of the tube?
B)How do I know which length of tube I require?
C)How are tubes - particularly the end fittings - specified? Do most tubes come with a T thread at each end to screw into the Barlow and T ring on the camera?
D)How do I check out that the tube is working optimally to do what it should do?
Any other advice and suggestions relating to prime focus digiscoping with a Barlow and a DSLR would be most gratefully received, thank you in advance, Pete
|Rate This Thread|
|Thread||Thread Starter||Forum||Replies||Last Post|
|Extension tube advice||Paul Pearson||Macro Photography||8||Tuesday 10th May 2011 11:07|
|70-300mm f/4-5.6 IS USM Kenko Extension Tube Min Focus||Nikon Kid||Canon||0||Tuesday 5th August 2008 13:29|
|Teleconverter or Extension Tube ?||barryj||Sigma & Other Third Party Lenses||8||Sunday 23rd September 2007 09:18|