Basically, I'd like to have a reference black that would have an effective dMax of 4 or higher for testing lens glare.
What I think would do the job is a box, say 6"x6"x12" with a 1"x1" square removed from one 6x6" side. The inside would be lined with black felt or possibly black printed glossy with DMax around 2.2 but at an acute angle such that it sloped from the front edges of the box to the center in the back. Any light entering would have a couple paths. It could bounce once from the non glossy surface and hence would be reduced relatively small aperture area together with the DMax. Specular reflections from the gloss surface would be attenuated through multiple bounces as each bounce moves it further inward toward the box end.
My guess is that I can achieve a DMax of >4 with a uniform ambient lighting. In such an environment with an ambient Lux of 100 I should expect to see luminance from the 1" square hole of less than .003 cd/m^2 which should be enough to measure lens flare.
Found this from Imtest.
http://www.imatest.com/support/image-quality/veiling-glare/http://www.imatest.com/images/Veiling_black_box_1849.jpgAnyone done this and/or have a way to measure or calculate the "blackness" of these?
