Tuesday, June 18, 2013

Treasury flower - Gazania rigens in deep reflected ultraviolet photography III

Today about the same Gazania flower Treasury flower - Gazania rigens in reflected ultraviolet photography using my "work horse" UV filter, the Baader-U filter, but this time comparing them to two other UV transmitting filters, a stack for longer wave UV using Schott UG1 and one for shorter using Schott UG11 plus as IR blocker Schott S8612 filter. But this time every image was individually white balanced. Lens used was the 94mm CERCO quartz fluorite lens. Light source was a modified for UV high power Xenon flash.

[click on image to see a larger one]

Visible light image using UV/IR cut filter:

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

UV image using a UG11 filter stack:

UV image using Jupiter-U filter:

UV image using a UG1 filter stack:

Interesting to notice, that those very different UV filters produce quite similar results, the deeper into UV reaching ones with finer details, the one rather on the long wave UV end, like the UG1 based filter stack shows less details and tints the image bluish, the latter most likely because of some blue leakage. Seemingly the UG11 + S8612 filter stack as well as the Jupiter-U filter produces quite similar detailled results than the Baader-U filter, but need more exposure and show some greenish overall hue. All that gets nicely visible.

I have written about that flower and those filters previously HERE.

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

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos