Calculating close-up rings (O-ring)

If a very small working distance (= object distance) is selected, small image details can be inspected. However, it is impossible to focus as close as you like, the lens has a close-up limit, also called minimum object distance (MOD). If you purposely want to deceed it, close-up rings must be added.

Note: Use “ other” from the drop down box to enter your values

Sensor size:
Focal length of lens:
Object size/ field of view in mm:
Minimum Object Distance (MOD) of lens in mm:

Calculated working distance:
Needed extension ring: