Wednesday, July 18, 2007

Guess which one has been shot using a quartz lens?

This is a test shot to compare a Fluorite/Quartz lens with a "normal" lens ("X135") for UV photography. The shots show one each per row. All done at f8 and using the new 2" Baader U-filter for the UV shots. The images are cropped/sized for about the same size for comparison. Focus was NOT completely identical, so don't use correct focus as as indicator for your guess, look out more for detail, sharpness & contrast.
[I used Nikon D70 + Baader 2" U-filter + X135 lens. UV shot about -10EV compared to VIS shot, identical postprocessing and resize for same appearance due to different focal length]

And your guess for the quartz lens is which one?

Here are two high resolution images if you click on them:

Some more specific shots with decent UV pattern may be seen here now, first the visible light shot:

and the UV shot:

Details (100% crop), first the visible light shot:

and the UV detail shot:

Oh, nearly forgot, the quartz lens is the first row in the first
two images, the second row is that older X135mm lens, I
calibrated for UV shooting. This was also used for all following
shots. The slight disadvantage is, that you focus in visible
light, flip the Baader U filter in front of the lens, make a
focus adjustment to the UV marker (like that red dot
indicating the IR mark) and shoot. Not such an effort if
you can save quite some bucks...

Stay tuned, more will follow on that subject, too...

More info on this very interesting field may be found on my site>