Optical Centering (Precisely Determined Bottom Weighting)?

[Andrew Lenz Jr.]

A photographer came in this afternoon and explained something that he called "Optical Centering" in some very geometric terms. I've made up a diagram to explain:
http://lenzarts.com/temp/OpticalCentering-LenzArts.pdf

Basically, it's bottom weighting but this process is very precise.

Anyone see this before? And maybe messed around with it some? I haven't had time to experiment with it yet.

Andrew

 

[Gregory K. Norris CPF]

I have seen this before, but never used it except to satisfy one very precise-thinking photographer some years ago. It makes good sense to use this formula in situations where you are fitting an image to a frame of predetermined size. In my case, it was making a set of 8x10 photographs fit into 11x14 frames, with the mats weighted at the bottom for a photography competition.

 

[Ormond Williams MCPF]

I wonder how close this comes to the 'Golden Mean'?

 

[Jini Lumsden MCPF]

Thanks for sharing this. I had not seen this before.

 

[Kai Vanuffelen]

I have seen it before in a framing book for do it yourselvers of the eighties that was probably written by someone with a mathematical background. The golden mean - wasn't that 3/8 on one side and 5/8 on the other?

 

[Jim Miller MCPF GCF]

The Fine Art Care and Treatment Standards (F.A.C.T.S.) in 1997 included FRM400, Using The Golden Mean for Proportional Divisions in Decorative Matting, attached here:

View attachment FACTS-FRM_400-Goldenmean.pdf