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Sigma SD15 DSLR for full spectrum radiation detection!

In terms of exotic spectra, I have a Sigma SD15 DSLR with the UV/IR blocking "dustcover" removed so as to allow full-spectrum radiation to impinge upon the mighty Foveon sensor. Also have a Marumi 700nm IR filter for the lens and a Kolari Visible Light filter for more normal shots.

Ted
 

Asher Kelman

OPF Owner/Editor-in-Chief
In terms of exotic spectra, I have a Sigma SD15 DSLR with the UV/IR blocking "dustcover" removed so as to allow full-spectrum radiation to impinge upon the mighty Foveon sensor. Also have a Marumi 700nm IR filter for the lens and a Kolari Visible Light filter for more normal shots.

Thanks for asking ...

Ted
That’s amazing!

What have you photographed!

Asher
 

Dr Klaus Schmitt

Well-known member
In terms of exotic spectra, I have a Sigma SD15 DSLR with the UV/IR blocking "dustcover" removed so as to allow full-spectrum radiation to impinge upon the mighty Foveon sensor. Also have a Marumi 700nm IR filter for the lens and a Kolari Visible Light filter for more normal shots.
Ted
Interesting Ted, I had a SIGMA camera with FOVEON sensor many years ago, unfortunately it did not well for UV.

Klaus
 

Asher Kelman

OPF Owner/Editor-in-Chief
So what is the experience with this novel setup?

it should be good for regular IR and exotic UV!

Asher
 

Nicolas Claris

Administrator/Moderator
In terms of exotic spectra, I have a Sigma SD15 DSLR with the UV/IR blocking "dustcover" removed so as to allow full-spectrum radiation to impinge upon the mighty Foveon sensor. Also have a Marumi 700nm IR filter for the lens and a Kolari Visible Light filter for more normal shots.

Ted
Ok! and then…
 
Interesting coloration of the layer images, Klaus. I comment because each layer, taken by itself, is monochrome. So did you choose a hue perhaps based on the peak wavelength of each layer?
 
Ah, I think I understand, thank you. When some apps decompose an RGB image, e.g. the GIMP or RawDigger, they render the channels as grayscale but other apps, like 'Show Image', render them in the appropriate monochrome hue.
 

Dr Klaus Schmitt

Well-known member
Ah, I think I understand, thank you. When some apps decompose an RGB image, e.g. the GIMP or RawDigger, they render the channels as grayscale but other apps, like 'Show Image', render them in the appropriate monochrome hue.
I used the same image and set the two unwanted channels to zero...
 
I play with a SD14 for false colour IR as the Foveon sensor gives completely different results to my converted Bayer cameras.
IR shows almost entirely in the red with this, adding an X1 (green) filter & using fluorescent WB generally give Aerochrome like results SOOC.


FWIW I found the Sigma RAW files a real pain with my normal editing software.
aa_SDI1437.JPG
a_SDI1424.JPG
 

Asher Kelman

OPF Owner/Editor-in-Chief
Wonderful to have your unusual window on the world.
Have you also experimented with B&W derivatives of these files?

What’s your procedure here?

Also can you use your camera with peopke and get good color without green artifacts to the skin as I have seen reported!

Asher
 
The procedure is pretty much the same as for everyday photography.
Remove the dust filter/IR block from the camera (a v simple procedure on the SD14) add lens & filter, select fluorescent WB & shoot adjusting EC aperture etc as required.

It's possible I might have tweaked the hue control sometimes in post processing but nothing drastic has been done.

The SD14 is old enough I've not bothered using it for normal photography or even B&W IR as I have converted cameras that do it better.
It should work fine for B&W IR if a suitable filter is added in front of the lens (with the dust protector removed)

If you were referring to skin tones in the aerochrome mode I've not done a lot of experimentation, a few test shots with my hand in the foreground and more readily to hand:
Here's another shot with the same set-up (with more IR in the lighting) which has a small amount of flesh visible
seafront garden aerochrome small by Mike Kanssen, on Flickr
I don't know if it's enough to judge the tones using this for portraits but it's the best I have readily to hand & I'm late for work!

The X1 filter is unusual in that it reduces the IR passing through (by about half) most other green filters either block nearly all the IR or let most of it through. Most normal photography filters transmit lots of IR...
 
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