I own EL-Nikkor 50 f2.8 and 80 f5.6 lenses. Given that enlarging
lenses are used at around f8 most of the time, I doubt that the f2.8
is worth trading 'up' to from the f4. Especially if you bear in mind
that you should focus through a grain magnifier at the exposing
aperture-i.e. f8 for critical sharpness. Focussing at maximum aperture
and stopping down will cause a small loss of grain shrpness due to a
focal length change in the lens. Try it with a grain magnifier at 2.8
and 8.
Stewart.
