Monday, June 18, 2012

[UV] Old Achromatic vs modern Cerco Quartz Fluorite Lens for Ultraviolet Photography

Well, you may remember that I have shown here results using an older quartz fluorite lens from a spectrometer system. Here that now tested against my Cerco 94mm lens using a Gazania rigens flower that I have shown here a few times before. The Cerco images ("in dubio pro reo") have been adjusted in size a bit, to compensate for the different focal lengths (94mm vs about 82mm).

Here the results and I leave it to you to determine which shot was done using which lens; it is easy anyway as I will show also 1:1 crops.

[click on image to see a larger one]

Visual shot:

UV using Baader-U filter:

Visual shot (detail):

UV using Baader-U filter (detail):

[the UV focus is not exactly identical for that last shot, so I'm not sure if that was caused by focus shift or most likely by a slight movement when I changed filters ... oh well]

Not that bad for such a relatively cheap part...

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

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