Sorry about the extensive quoting :-) Guy Glorieux wrote: > > We chose a 40" focal length ... > While the tests strips we had placed on the extremities > of the frame suggested then that we might be underexposed, the centre, > by that time was quite over exposed. ... > The next stage for us is to do a contact print of the paper negative > into a positive image. ... > We need to illuminate an area 12.5 x 8.5 feet, > and there is about 7 stops density difference between the centre of the > image ... > working with a single lamp projector 15 feet above the print ... > the last stop and a half is really hard to > tackle.... My suggestion, for what its worth, is to attempt to emulate the exposure conditions as closely as possible for the printing. I'd try a bulb hung 40" from the paper to try to duplicate the light falloff you go when taking the image. Naturally I'd try to minimise stray reflections. At 40 inches even a bulb will pretty much approximate a point source. Steve
