Ultraviolet Blues

jaapv

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A very good UV camera as well, the M8:
B&W 403 filter, Iso 640. 1/30th Summarit 1.5/50 @ 4.0

Newer lenses don't transmit UV, so it was this one or a Jupiter. Focussing was a lot more accurate than I expected, just the other way around from IR photography, but the Summarit has a surprisingly small deviation and infinity is infinity. I bracketed focus.

uv.jpg
 
Brian Sweeney said:
Very nice results.

How do the results from the M8 compare with film?

I would not know; I've never done UV on film. As a matter of fact this is my first UV shot ever.
 
Jaap,

congrats for your start to explore a completely new world only a few made it up to now!! The reflection of the skye, the flat lying gravestones indeed IS reflected UV. But this pic you shot could also contain quite some IR and you would not even know it since the filter you used leaks substantially IR (the grass + leaves tree color indicate that btw. A real UV image looks nearly monochrome). Here the graph about the nearly identical Schott Ug1 filter:

UG1ltrans.gif


To be on the safe side you could use the Baader 2" U-filter (ca. EUR220) and repeat the test, then we would know (this filter has IR completely suppressed):

75270546.jpg


Cheers, Klaus

(here is my UV site with filter/lens tests and real results: http://www.pbase.com/kds315
 
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Brian Sweeney said:
Film's sensitivity extends fairly deep into UV, should go past the cover glass of a CCD.

You're right Brian, a CCD does max some 300..350nm whereas film (esp. b/w film) goes at least to 250nm

Cheers, Klaus
 
These are some landscape UV images shot in 300..400nm UV window using the Baader 2" U-filter (I call it UG11xx since it is based on Schott Ug11 with 100layer dichroic overcoating)

73905100.jpg


73905103.jpg


and a flower (deep red rose) would look like that for instance:

78548629.jpg
 
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