Access Auto-focus and Aperture controls on attached lenses.
13mm, 21mm, 31mm rings included.
What do the different sizes of tubes do™
the following formula to calculate the magnification from specific extension tube sizes:Magnification = Extension Tube Length / Lens Focal Length
Example: using a 31mm extension tube between a 50mm lens and a camera body would result in magnification of 0.62x (31 mm / 50 mm).
Using all three with a 50 mm lens would give you a magnification factor of 1.28x (64 mm / 50 mm). That’s close. Past 1x and you find yourself in a strange, almost alien, world of details.