View Single Post
Old 06-01-2009, 09:22 PM
bojan's Avatar

bojan is online now
Join Date: Jul 2006
Location: Mt Waverley, VIC
Posts: 5,950

Macro extension tubes are here to increase the distance between sensor and lens, so that lens could focus on objects that are closer.

There is formula:

1/FL = 1/A +1/B

where A and B are distances between optical centre of the lens and object and sensor.
If you work it out a bit, you will see how it works...

Last edited by bojan; 06-01-2009 at 09:33 PM.
Reply With Quote