• Ultraviolet Photography
  •  

Person portrait in UV, Vis, NIR, SWIR

Infrared UV Portrait SWIR
10 replies to this topic

#1 nickspiker

    Member

  • Members
  • 12 posts

Posted 03 April 2014 - 19:06

Ultraviolet, visible, infrared, short wave infrared comparison
UV taken with a full spectrum Sony A7, and the filter stack consists of Schott UG11 - 2mm, Schott 8612 - 2mm, and interference film coating that blocks from 600-900nm
Vis taken with a standard Sony A7
IR taken with a full spectrum Sony A7 and a Hoya R72
SWIR taken with http://www.infraredl...ve_Camera.shtml and a 1500nm long pass filter
The dark skin in the SWIR shot is because the water absorption at 1450nm http://upload.wikime..._absorption.png
Attached Image: Spectral comparison.jpg

#2 nfoto

    Former Fierce Bear of the North

  • Owner-Administrator
  • 2,356 posts
  • Location: Sørumsand, Norway

Posted 03 April 2014 - 19:18

Now, that is an intriguing example of spectral responses. The short wave IR (1450-1550 nm) is generally stated to be outside the photoactinic range, so I would dearly love to have the technical details behind this and the other samples shown.

Welcome to the forum, by the way.

#3 Shane

    Member

  • Members
  • 373 posts

Posted 03 April 2014 - 19:44

Nice example. Since 1450-1550nm exceeds the band gap of silicon, I assume this is some form of hyperspectral imager incorporating an InGaAs focal plane array imager? Looking forward to finding out.

Edited by Shane, 03 April 2014 - 19:45.


#4 colinbm

    Member

  • Members(+)
  • 1,306 posts
  • Location: Australia

Posted 04 April 2014 - 00:58

Thanks for posting this here Nick, it deserves the attention.
At what wavelength does the transition of reflecting light clear skin become absorbing black ?
Cheers
Col

Edited by colinbm, 04 April 2014 - 01:00.


#5 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 7,404 posts
  • Location: USA

Posted 04 April 2014 - 15:02

Oh man that is a very cool shot in the looooongwave IR range.
Do please give us some details about that shot!!

My (uneducated) guess on this one is that the long IR has penetrated well beneath the skin and is revealing blood???

This is a great comparison photograph for illustration of the 'look' of various wavelengths.
I look forward to more interesting work from you.
Andrea G. Blum
Often found hanging out with flowers & bees.

#6 nickspiker

    Member

  • Members
  • 12 posts

Posted 04 April 2014 - 15:45

View PostShane, on 03 April 2014 - 19:44, said:

Nice example. Since 1450-1550nm exceeds the band gap of silicon, I assume this is some form of hyperspectral imager incorporating an InGaAs focal plane array imager? Looking forward to finding out.
Germanium sensor

#7 nickspiker

    Member

  • Members
  • 12 posts

Posted 04 April 2014 - 15:46

View Postcolinbm, on 04 April 2014 - 00:58, said:

Thanks for posting this here Nick, it deserves the attention.
At what wavelength does the transition of reflecting light clear skin become absorbing black ?
Cheers
Col
Right above 1400nm it turns jet black

#8 nickspiker

    Member

  • Members
  • 12 posts

Posted 04 April 2014 - 15:46

View PostAndrea B., on 04 April 2014 - 15:02, said:

Oh man that is a very cool shot in the looooongwave IR range.
Do please give us some details about that shot!!

My (uneducated) guess on this one is that the long IR has penetrated well beneath the skin and is revealing blood???

This is a great comparison photograph for illustration of the 'look' of various wavelengths.
I look forward to more interesting work from you.
Not so much blood, as it is water in the skin

#9 JCDowdy

    JCDowdy

  • Members
  • 1,159 posts
  • Location: Arlington, TN

Posted 04 April 2014 - 23:05

Germanium?
I was going to guess InGaAs too!

I have been reading up on these http://www.sensorsinc.com/index.html but not bought one yet, now must reconsider!

Your link has a brochure that calls the camera a Ge enhanced CMOS with VIS-NIR-SWIR range 300-1600nm.

Pretty cool stuff man! http://www.imagesens...lepeak_swir.pdf

So what does it do with your UV filter stack mounted on it?????

And welcome by the way!!
- John

#10 nickspiker

    Member

  • Members
  • 12 posts

Posted 05 April 2014 - 16:20

View PostJCDowdy, on 04 April 2014 - 23:05, said:

Germanium?
I was going to guess InGaAs too!

I have been reading up on these http://www.sensorsinc.com/index.html but not bought one yet, now must reconsider!

Your link has a brochure that calls the camera a Ge enhanced CMOS with VIS-NIR-SWIR range 300-1600nm.

Pretty cool stuff man! http://www.imagesens...lepeak_swir.pdf

So what does it do with your UV filter stack mounted on it?????

And welcome by the way!!
- John
I've obsessed over sensorsinc for a while too, haven't we all :)
I'd like to see the 2,000nm band and see what things look like there, but I have a bit to discover at 1,500nm first
Haven't tried UV with it yet, but I thought about it, and it will happen, and you guys will hear about it soon!

#11 OlDoinyo

    Member

  • Members(+)
  • 675 posts
  • Location: North Carolina

Posted 07 November 2014 - 02:59

That last shot is a good demonstration of the O-H symmetric and asymmetric stretching modes of the water molecule. I've seen that absorption in many a spectrum, but never in an image before.