Jump to content
UltravioletPhotography

Bloodstone(?) Ghostie


Andrea B.

Recommended Posts

29 April 2018 EDIT: I don't think my ghostie rock is a bloodstone after all. I found a mineral called ruby zoisite which seems to be what I have? I'm not knowledgeable about minerals in spite of that geology course I took years ago in college.

 

I have this small bloodstone rock which seems to have a fluorescing ghostly face. I was working on the photograph this morning trying to retrofit a D200 white balance profile to it just recently made using the Grey Target.

 

(Review: This is a US Innovations grey card used for white balancing UVI visible fluorescence images under certain filters/lights and for standardizing WB in UVI-VF images made with other filters/lights. We are not associated with USI in any way.)

 

I have three renditions of the bloodstone rock:

  • Raw Digger, raw composite, added contrast & saturation, no white balance applied.
  • Photo Ninja, white balanced, D200-profiled where the WB was made using the Grey Target under a 365 nm UV-Led in the dark.
  • Capture NX2, with neutral picture controls, Daylight 5200 K white balance.

No sharpening was applied in any of the three conversions. A small amount of midtone contrast was used. Conversion TIFs were down-sized to postable JPGs in Photo Mechanic. No sharpening was applied to JPGs.

 

What I'm looking for here is the accuracy of the colors, so I did not want to fuss with sharpening - only a bit of detail enhancement. And I tried to clone out some of the more awful lint.

 

One interesting aspect of these three conversions was that the raw composite version showed much greater detail in the red areas. However, the raw comp really does not display the strong red fluorescence actually seen. In the other two versions the red fluorescence is more accurate in intensity. And that seems to mean that the strong fluorescence does obscure some details. So I suppose you might have to decide between fluorescent accuracy (in intensity) and fluorescent details being lost. Me, I'd would go with the glow when finishing one of these photos for display.

 

Gear [D200-mod + (Novoflex 35/3.5 + Baader UV/IR-Cut Filter) + Unfiltered Nichia 365nm UV-Led]

We have been through many recent discussions about the necessity of filtering the UV illumination used in UVIVF work to be sure no violet or blue leaks from the torch contaminate the visible photo. Back in 2009 when I made this photo I was just happy to get anything at all. Hadn't thought much about the finer points of UVIVF back then.

 

Exposure [f/3.5 for 1/1.5" @ ISO-400]

 

Raw Composite

bloodstone_uviVisFluor_365uvLed_20091015wf_32895rawCompPf.jpg

 

Daylight 5200K White Balance

bloodstone_uviVisFluor_365uvLed_20091015wf_32895pfDay5200.jpg

 

Grey Target White Balance

bloodstone_uviVisFluor_365uvLed_20091015wf_32895pnProfiledPf.jpg

Link to comment

Here is the visible bloodstone rock. Supposedly bloodstone has hematite inclusions, but this doesn't look like hematite?? I'm way out of my comfort zone when attempting to classify minerals!

29 April 2018 EDIT: This might be ruby zoisite?

bloodstone_vis_flash_20091015wf_32878pn01.jpg

 

 

 

 

The UV version just for completeness. Lots of noise. Might be time to reshoot this with a better camera and better light.

bloodstone_uvBaader_365uvLed_20091015wf_32889pn.jpg

Link to comment

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...