Just thinking out loud here but how about this: Pull the lens tubes out of the fixtures. Leave the tubes assembled (keep the individual lenses in the tubes) Hold the lens tubes one at a time over a flat surface and measure the relative heights at which they focus. When I've done this, I've usually been in a space with tubular fluorescents overhead and it was easy to place a sheet of paper on a work bench and make reference marks of the fluorescents when they were in focus. This wouldn't give me precise information but was definitely a quick and easy way of comparing the various focal lengths and sorting them into matching groups.There's complicated reasons why I can't just turn them on and measure the beams. Also those are 360 Qs, although I have the data sheets for 3.5Qs. I was hoping to be able to tell by lens configuration which was which.
I know that's true of the 360Q's, but is that also the case with the 3.5's as well? I'll have to take a closer look at the bodies I have and make sure they're the same.
This is an interesting idea. Thanks for the suggestion.Just thinking out loud here but how about this: Pull the lens tubes out of the fixtures. Leave the tubes assembled (keep the individual lenses in the tubes) Hold the lens tubes one at a time over a flat surface and measure the relative heights at which they focus. When I've done this, I've usually been in a space with tubular fluorescents overhead and it was easy to place a sheet of paper on a work bench and make reference marks of the fluorescents when they were in focus. This wouldn't give me precise information but was definitely a quick and easy way of comparing the various focal lengths and sorting them into matching groups.
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