I've made a focus chart to test parfocal lenses.
 

I’m making a focus chart to check if my lenses are parfocal.
It uses my computer screen and a target taped at 45 degrees.
You can view it here: #13
Lenses

The system works, but I'd like to improve it... so I'm posting on a few forums.
If anyone with graphic skills wants to help... please write.


Bill Kerrigan
bill@kerrigan.ca
http://www.kerrigan.ca