Greetings from France!

[Hornblende]

Hi everyone!

It is a great joy to be here :)

 

I am a french student in geology at the Ottawa university, next week I start a master study about gold deposits in Peru.

I am also a gemologist, I am passionated by gemstones since my youth.

Regarding photography I am mainly interested by imaging atmospherical phenomenon such as sundogs, sun halos, rainbows and other oddities. I am also interested in astrophotography, the Sun in particular, I have a dedicated Lunt solar refractor for viewing the solar disc in the h-alpha band. If you are wondering what my profile picture might be, it is the sun in ultraviolet (Calcium H line) I took with an homemade spectroheliograph.

 

I have been introduced to IR photography by chance while looking for photography tutorials on Youtube. It amazed me at the point I NEEDED an IR camera to explore the invisible world I couldn't see (dark clothes and leaves turning white, seeing through wine, awesome). Subsequently I learned about ultraviolet photography thanks to this forum and Dr Klaus Schmitt's blog. But being short on money I had to wait until I could get all the gears I needed.

 

In the meantime I got a project in mind : could I use multispectral imaging to identify gemstones and detect fakes/treatments?

I have no clues if it might work but I believe I should be able to identify gemstones by there appearence resulting from multispectral imaging. I made some tests in 850nm IR and got surprising results I did not expected (dark green tourmaline getting clear as glass, pale green/yellow peridot getting dark, turquoise getting completly black...). I think I got something here, I should get some nice results in the future :)

 

For now I use my astro-camera Zwo ASI-120MMs with a CCTV lens, a 850nm filter and the Baader U filter. Unfortunately I get pretty bad results in UV because the CCTV lens has a very bad UV transmission.

I plan to get a Nikon 40/70D and the EL-Nikkor 80mm in the near future for macro-imaging my gemstones.

Oh by the way I tried the Baader U on my mom's Leica M9 + Summiluxe 50mm/1.4, it works great!

 

That's all!

I am looking forward to chat with you :)

 

Fluorescent zinc ore from Sterling Hill, New Jersey.

[Andy Perrin]

Welcome! That's an awesome image! Be careful about skin exposure to UV, though. (Andrea, I beat you to it!)

[Hornblende]

Thanks Andy!

 

Haha, I got a sunburn in that mine.. I am wayy more careful now.

[Andrea B.]

Hello Martin and welcome to UVP!

 

That is the coolest thing that you have a Lunt solar refractor! One of my favorite trips was to visit the National Solar Observatory on Kitt Peak in Arizona. We went on a delightful and impressive tour of the facility.

 

Photographing minerals and gemstones in UV/IR or capturing their UV-induced fluorescence is fascinating. I have a little box of various minerals I've collected over the years from which I've made various photos. I'm always hoping for more time to post them, but alas....

So we will look forward to seeing your gemstone work. Hope you are able to aquire a D70 and that EL-80 soon. BTW, get the old version of EL-80.

 

Interesting that the Leica M9 works well for UV. I always suspected it would but so far had never heard of any results. Post us a UV photo from it if you get the time.

[Hornblende]

Thanks Andrea :)

 

Below is a photo of Gypsophila in UV I took with the Leica. The UV signature is evident : the center of the flowers appear black (in visible light they are entirely white).

 

8s - f4 - 640 ISO - halogen lamp

 

[Andrea B.]

Thank you for the M9 photo. It looks good! I'd enjoy a having B&W digital camera for general reasons, but nice to see this one is also good for UV.

[Hornblende]

Oh, I forgot to mention it is the color version of the M9. I put the picture in B&W because I couldn't achieve a correct white balance.

[Andrea B.]

ah. OK, thanks for the update. :)

[nfoto]

Hi, welcome to UVP. You have an interesting 'astro' camera - is it ,modified in any way to work for UV? I guess UV capable lenses with smaller mount sizes can be made less expensive than the legendary Coastal Optics and UV-nikkor/Rayfact ones?

[Hornblende]

Hi Bjørn :)

My astro camera is a bare monochrom CCD: https://astronomy-imaging-camera.com/products/usb-3-0/asi120mm-s/

However I stopped using it since I got my Full Spectrum modified Canon 6D, much more handy.