Quote Originally Posted by Drew Wiley View Post
Thanks, Pere. Yes, I have a lux meter, but also a special instrument about a thousand times more accurate. I'm familiar with these variables.
Drew, near a year ago I spent a Sunday afternoon measuring flare. I measured 9.3 stops difference for flare in a Sironar-N 300 MC (c.1980), this is 1 to 630, or 0.15% flare. And I think that most of the reading was not due lens flare, but from other stray light generated after lens.

I used a method based in Ctein's Post Exposure, page 60, but using a 0.1 lux luxmeter. Ctein measured 8.2 stops, but his reading included enlarger bellows generated flare and I guess that his lens was not MC.

From that test I concluded that flare generated by a modern MC lens is not a concern, but light from excessive circle of image was a concern. Later I measured flare with lens in a CAMBO 8x10 with the huge image circle of the Sironar 300 illuminating the bellows, in those conditions I measured x23 more flare.

Just a personal test in my learnig process.