Sunday, February 17, 2013

100mm Focotar Enlarger Lens vs CERCO 94mm quartz fluorite lens for reflected UV photography

Today another comparison between a special UV lens and a conventional, but UV capable enlarger lens, a f5.6/100mm Focotar. I have done a similar comparison here and here as well as here. I'm using beautiful Valentine Day's roses for that and my "work horse" UV filter, the Baader-U filter plus the deeper reaching Jupiter-U filter. Lenses used are a CERCO 94mm quartz fluorite lebs as well as a capable for UV 100mm Focotar enlarger lens. Light source was an UV enhanced Xenon flash. All shots done at f8 and presented on a side-a-side format for easier comparison, right: enlarger lens, left CERCO quartz fluorite lens.

[click on image to see a larger one]

Visible light image:

UV image using Baader-U filter (approx. 320-395nm, effective peak approx. 375nm):

UV image using Jupiter-U filter (approx. 280-385nm, effective peak approx. 365nm):

It gets pretty obvious that this enlarger lens reaches surprisingly close to the CERCO quartz flourite lens! The difference is there, yet quite small. Quite a useful lens!

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

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