UV photography - Cookbook style
I'm sure I get flamed for this but here it is:
UV photography -Cookbook style:
1) get a suitable lens, uncoated or single coated, simple lens design like a
triplet. You have to try things out, some work, some don't. EL Nikkor
enlarger lenses are not bad, get a 75 or 80mm >older< full metal type or the
3.5/63mm (rare and expensive now). Needs a focusing mount or mounted on
a bellows. Good for close up, not for infinity. Ideally a UV Nikkor 105mm (ca.
$4.500) fluorite-quartz lens but this one is out of production. Tack sharp,
also for visual and IR. There is a currently available replacement plus two
other quite similar lenses.
2) get a suitable filter. The new 2" Baader U-filter (I call that >UG11xx<)
ist the best you can get, 300...400nm tranmission range, IR perfectly
suppressed which is important for most DSLRs due to their high IR and low
UV sensitivity. Be prepared to expose ca. 8 stops more than normal. My usual
setting on an sunny to overcast day is 2..4" @ f11 ISO200 using a Nikon D70.
3) get a suitable UV enabled camera. My finding is that the Nikon D70(s) is
the best value for money for UV. D80 and D200 are said to work well either,
but need the internal filter removed first. CANON shooters - sad day, does
not work with Canon DSLRs, their filters and used chips do NOT allow UV.
4) Use a sturdy tripod to allow 2...4" exposure time, sometimes much longer
though. UV is strongest 90 degrees to the sun, don't shoot in bright sun due
to high IR content (no longer a big problem with the UG11xx but you might
still get hotspot effects or IR flare.)
5) for comparison shots I shoot visual light first and then attach the
filter and shoot UV with exactly the same framing. Be careful not to move
the camera. If using an older lens, focus closer. This needs to be tested
out, my finding is that the f8...f11 position on the DOF scale might work.
Shot RAW files or high resolution JPEGs. PRO's do RAW, but for simple
testing JPEG will do.
6) Upload pictures and process pictures. They will look very red, but what
you see is UV, depending on camera, mainly in the green and somewhat blue
channel (D70). So either you process them to black/white or whitebalance,
then adjust to taste. UV has no "color" so you may do what you like.
7) enjoy the sometimes strange and exotic results!
This is in condensed form the result of some years of research, Bjoern Roesletts
findings and excellent site
http://www.naturfotograf.com/index2.html,
many own tests and a lot of errors and dead end streets.
I have plenty of filters, lenses etc available, since I tested so much for the last years.
I also have special calibrated lenses now for UV, some results published here:
https://www.nikoncafe.com/vforums/showthread.php?t=110799
My UV work and lens testing can be seen on pbase:
http://www.pbase.com/kds315
Hope that helps, if not, ask me,
Cheers,
Klaus