I have modified the SX-70 for 600 film, which means the Neutral Density ND filter in the
exposure meter has to go, and about ~ND4 must be applied to the lens to 'kill' some of the
light getting to the film. This test is using some ends from a developed 35mm strip of Ilford
FP4 negative material. It seems that 2 thicknesses work in sunlight, but I think it takes too much
quality from the lens. I may have to be more scientific, and use a 'proper' filter and some duct tape. ;-)