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Tricolour IR Fluorescence (now completed)

TriColour Infrared Fluorescence
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#1 Bernard Foot

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Posted 10 April 2021 - 14:39

I took advantage of the long winter nights to do some fluorescence photography. Here are some results of UV- and Visible-Induced IR fluorescence, done in tri-colour.

I’ve also included standard visible and a few UVIVF images for comparison.

(There are some more tri-colour IR Fluorescence images, using rock samples at https://www.ultravio...__fromsearch__1 )


The Tricolour channel assignments are:

Red Channel: 1000nm

Green Channel: 850nm


Blue Channel: 750nm


Light Sources:


UV: Nemo Torch


Visible: Lumitact LED torch.


Narrower-band Excitation

My available UV light sources and filters did not allow for excitation using a narrower band of the UV spectrum, but this was possible using visible light. This set of images includes Visible-Induced IR Fluorescence excited by white, blue (470nm), green (520nm), and red (635nm). Apart from colour cast, there is not a lot of difference, and so all later Visible-induced IR Flourescence images use just white excitation.

The blue and red colour casts on the blue- and red-excited images cannot be due to any form of blue or red visible light leak: blue and red in the image is caused by transmission through 750nm and 1000nm bandpass filters and there is no reason why blue light would leak only through the 750nm filter and red light would leak only through the 1000nm filter.

Orchid:

Visible..........................................................................UV-Induced Visible Fluorescence
Attached Image: 007 Vis Orchid Pair.jpg Attached Image: 007 UVIVF Orchid Pair.jpg

UV-Induced IR Fluorescence
Attached Image: 007 UVIIRF Orchid Pair.jpg

Visible (White)-induced IR Fluorecence......................Visible (Blue)-induced IR Fluorescence
Attached Image: 007 VIIRF Orchid Pair - White.jpg Attached Image: 007 VIIRF Orchid Pair - Blue 470nm.jpg

Visible (Green)-induced IR Fluorecence.....................Visible (Red)-induced IR Fluorescence
Attached Image: 007 VIIRF Orchid Pair - Green 520nm.jpg Attached Image: 007 VIIRF Orchid Pair - Red 635nm.jpg


White Balancing

How do you white balance images like this? I started off with using WB based on a white section of a rock, but this often just gave visually uninteresting so I started WBing against elements of the image. This example shows the differences this can produce.

Lily

Visible....................................................................................................................UV-Induced Visible Fluorescence
Attached Image: 016 Vis Lily White.jpg Attached Image: 016 UVIVF Lily White.jpg

Visible-Induced IR Fluorescence:

Rock WB method:..................................................................................................WB against dark area at top-left:
Attached Image: 016 VIIRF Lily White - White.jpg Attached Image: 016 VIIRF Lily White - White - Re-WB against dark area top left.jpg

WB against leaf:
Attached Image: 016 VIIRF Lily White - White - Re-WB against spiky leaf.jpg

UV-Induced IR Fluorescence:

WB against leaf:
Attached Image: 016 UVIIRF Lily White - Re-WB against spiky leaf.jpg

Forsythia:

Visible:
Attached Image: 002 Vis Forsythia.jpg

UV-Induced IR Fluorescence:................................................................................Visible-Induced IR Fluorescence:
Attached Image: 002 UVIIRF Fosythia.jpg Attached Image: 002 VIIRF Forsythia.jpg

Flaming Katy:

Visible:..................................................................................................................UV-Induced Visible Fluorescence:
Attached Image: 005 Vis Flaming Katy.jpg Attached Image: 005 UVIVF Flaming Katy.jpg

UV-Induced IR Fluorescence:...............................................................................Visible-Induced IR Fluorescence:
Attached Image: 005 UVIIRF 380nm Flaming Katy WB on Leaf HiSat.jpg Attached Image: 005 VIIRF Flaming Katy WB on Leaf HiSat.jpg

For both of these images, saturation has been increased and WB was against the leaf.

Winter Aconite:

Visible:
Attached Image: 011 Vis Winter Aconite Eranthis Cilicica .jpg

UV-Induced IR Fluorescence:...............................................................................Visible-Induced IR Fluorescence:
Attached Image: 011 UVIIRF Winter Aconite Eranthis Cilicica.jpg Attached Image: 011 VIIRF Winter Aconite Eranthis Cilicica - White.jpg

Chrysanthemum:

Visible:
Attached Image: 013 Vis Flower Group 1.jpg

UV-Induced IR Fluorescence:.................................................................................Visible-Induced IR Fluorescence:
Attached Image: 013 UVIIRF Flower Group 1.jpg Attached Image: 013 VIIRF Flower Group 1.jpg

Visible:...................................................................................................................UV-Induced IR Fluorescence:
Attached Image: 020 Vis Chrysanthemum.jpg Attached Image: 020 UVIIRF Chrysanthemum.jpg

Jasmine:

Visible:
Attached Image: 017 Vis Jasmine.jpg

UV-Induced IR Fluorescence:................................................................................Visible-Induced IR Fluorescence:
Attached Image: 017 UVIIRF Jasmine - re-WB on stamen..jpg Attached Image: 017 VIIRF Jasmine - White - re-WB on stamen.jpg

WB was against the stamen tip.

Snowdrop:

UV-induced Visual Fluorescence:.........................................................................Visible-Induced IR Fluorescence:
Attached Image: 021 UVIVF Snowdrop 254nm WB on Petal.jpg Attached Image: 021 VIIRF Snowdrop - White - WB on light part of petal.jpg

These imges were WBed on the light part of the petals.

Daffodil:

Visible:..................................................................................................................UV-Induced Visible Fluorescence:
Attached Image: 022 Vis Daffodil.jpg Attached Image: 022 UVIVF Daffodil.jpg

UV-Induced IR Fluorescence:...............................................................................Visible-Induced IR Fluorescence:
Attached Image: 022 UVIIRF Daffodil WB on Stigma head.jpg Attached Image: 022 VIIRF Daffodil WB on Stigma head.jpg

WB was against the stigma tip

Tulip:

Visible :...............................................................................................................UV-Induced Visible Fluorescence:
Attached Image: 023 Vis Tulip.jpg Attached Image: 023 UVIVF Tulip.jpg

UV-Induced IR Fluorescence:.............................................................................Visible-Induced IR Fluorescence:
Attached Image: 023 UVIIRF Tulip WB on Stigma.jpg Attached Image: 023 VIIRF Tulip WB on Stigma.jpg

These last two images were WBed on the stigma.

And now something completely different – Sugar Cubes:

Visible:..............................................................................................................UV-Induced Visible Fluorescence:
Attached Image: 018 Vis Sugar Cubes.jpg Attached Image: 018 UVIVF Sugar Cubes-1.jpg

UV-Induced IR Fluorescence:...........................................................................Visible-Induced IR Fluorescence:
Attached Image: 018 UVIIRF Sugar Cubes.jpg Attached Image: 018 VIIRF Sugar Cubes.jpg

Edited by Bernard Foot, 10 April 2021 - 15:19.

Bernard Foot

#2 Andy Perrin

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Posted 10 April 2021 - 15:33

What is that second sugar cube? Is that brown sugar?

#3 Bernard Foot

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Posted 10 April 2021 - 15:46

View PostAndy Perrin, on 10 April 2021 - 15:33, said:

What is that second sugar cube? Is that brown sugar?

Yes. I was surprised at the difference between white and brown.Perhaps that's why the Rolling Stones thought so highly of it.
Bernard Foot

#4 dabateman

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Posted 10 April 2021 - 18:50

These photos are excellent.
Oh and Bernard, Rolling stone's Brown sugar is not what you think.
Time for you to carefully read the lyrics.

#5 colinbm

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Posted 11 April 2021 - 08:13

Fantastic results Bernard.
Fascinating are the different fluorescence in IR with each wave bans used.......seems it is never ending......