Quote Originally Posted by Walter Glover
Light meter linearity is a crucial factor ...

I took one of those black card sheets for displaying a
selection of 6x6 trannies and in each aperture I placed
a different Wratten ND gel -
all the way to an ND 3.0.
I suppose you back-lighted those 10 gels? That method may work
well with my 8 degree L-228 Sekonic and many of the camera based
meters in spot mode. I'd think those 10 ND gels cost something?

Perhaps a point light source and measured distances will work
well. I think a clear filament bulb against large dead black
background worth a try. Any opinions? Dan