I have worked both with paper and film negatives over the past twenty
years, sizes ranging from 8x10, 7x17, 8x20, 11x14 and 12 x 20 inches (both
colour and black & white).
Problems printing in the early days when I used paper negatives was
overcome by printing wet.
Nowadays I use a vacuum frame and for awhile used the point source light
that came with it. Once the bulb burnt out I went back to traditional
tungsten light bulbs.
I have always figured any lack of sharpness visible to the human eye was
optical in nature, caused by lenses or camera problems (shake etc.) rather
than by the printing light source.
R.R. 3 Sackville
Canada E0A 3C0