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Allamanda cathartica [Golden Trumpet]


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#1 colinbm

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Posted 23 January 2015 - 12:38

Borrott-Maloney, C. (2015) Allamanda cathartica L. (Apocynaceae) Golden Trumpet. Flowers photographed in visible, infrared and ultraviolet light. UV-induced visible fluorescence and red/blue-induced infrared fluorescence are also included. http://www.ultraviol...golden-trumpet/

Coombabah, Queensland, Australia
Friday, ‎23 ‎January ‎2015
Wildflower in home garden

Synonyms:
  • Alamanda amarela (Portuguese, Brazil)
  • Yellow Allamanda
Comment:
Allamanda Flower, Seven Multispectral Images.
This Brazilian native is grown around the world as an ornamental vine. In many places A. cathartica has naturalized including Queensland and Western Australia in Australia.

Reference:
1. Australian Plant Image Index (2015) Allamanda cathartica, Australian National Botanic Gardens, Canberra, Australia.
2. Australian Plant Name Index (2015) Allamanda cathartica L., Australian National Botanic Gardens, Canberra, Australia.
3. Forster, P.I. in Orchard, A.E., (Ed) (1996) Flora of Australia 28: 143, Map 184. CSIRO Publishing, Clayton VIC, Australia.

Equipment:
The camera is the Sigma Foveon DP2, APS-C compact with a fixed 24mm lens, & without its IRC (full spectrum converted).
Note from UVP: The 3-layered Foveon sensor produces false-colour files in UV and IR which are not easily translated to the typical false-colour palette given by Bayer-CFA cameras seen elsewhere on UVP.

I have two MTE U301 365nm flashlights now, so I used them both for the UV shots. Both are fitted with U340 filters to keep the light below 400nm. One is in the original form and gives a spot light with a soft spread. The spot is the size of the flower's opening, about 30mm. The other is without the reflector head and gives a wide even spread of light at 120 degrees.


Visible with CFL & Flash
Camera settings: ISO 100, f5 at 1/40th second, with original IRC.
Attached Image: SDIM6368-Allamanda-Flower-VIS--process-crop-web label.jpg


Ultraviolet Induced Visible Fluorescence with 2 X MTE U301 (365nm) Flashlights and U340 Filters
Camera settings: ISO 100, f5 at 6 seconds, with original IRC + GG420.
Attached Image: SDIM6387-Allamanda-Flower-UVIVF-process-crop-web label.jpg


Ultraviolet with 2 X MTE U301 (365nm) Flashlights and U340 Filters
Camera settings: ISO 100, f5 at 0.3 second, with Baader U2.
Attached Image: SDIM6380-Allamanda-Flower-UV-process-crop-web label.jpg


Blue Induced Infrared Fluorescence with 445nm LED
Camera settings: ISO 100, f5 at 15 seconds, with RG9.
Attached Image: SDIM6389-Allamanda-Flower-Blue-LED-Induced-IR-Fluoro-RG9--process-crop-web label.jpg


Red Induced Infrared Fluorescence with 635nm LED Light
Camera settings: ISO 100, f5 at 15 seconds, with RG9.
Attached Image: SDIM6390-Allamanda-Flower-Red-Led-Induced-IR-Fluoro-RG9-process-crop-web label.jpg


Infrared with Incandescant Light
Camera settings: ISO 100, f5 at 1/400th second, with RG9 (above 720nm)
Attached Image: SDIM6391-Allamanda-Flower-IR-RG9--process-crop-web label.jpg


Visible with 445nm Blue LED Light
Camera settings: ISO 100, f5 at 2.5 seconds, with original IRC.
Attached Image: SDIM6392-Allamanda-Flower-Blue-LED-light-process-crop-web label.jpg

Thanks very much to Andrea for putting everything right, so it could be placed in the formal presentation.
Cheers
Col

Published: 23 January 2015
Updated: 29 January 2015

#2 Andrea B.

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Posted 23 January 2015 - 14:23

Very nice work, Col.
Andrea G. Blum
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#3 colinbm

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Posted 23 January 2015 - 15:20

Sorry Andrea & all the other viewers, but I got too excited & decided to add another three to the multi-spectral collection.
What have I left out.......
Col

#4 Andrea B.

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Posted 23 January 2015 - 16:40

We need to place the captions closer to the photos??

*****

The Infrared photos are super cool !! Look at that nice little glow in the center of the flower iin #5 and #6.

Added Later: Col, try making a Visible photograph with the Blue LED illumination. Sometimes a UV marking will show up in violet/blue light.

Do you know the bandwidth of those blue & green LEDs ??
Andrea G. Blum
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#5 colinbm

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Posted 23 January 2015 - 19:38

Thanks Andrea
I could break-up the photos, but then they won't be a sixtych....

"Added Later: Col, try making a Visible photograph with the Blue LED illumination. Sometimes a UV marking will show up in violet/blue light."
I will do this later when I wake-up properly.

I just tested the RGB LED again on my USB Spectroscope.
The Blue LED is at 445nm, & the Red LED is at 635nm.

Cheers
Col

#6 Andrea B.

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Posted 23 January 2015 - 20:43

The bandwidth, not the wavelength. How much around blue/red is there around the peaks of 445/635?
Just curious. B)
Andrea G. Blum
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#7 colinbm

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Posted 23 January 2015 - 20:50

Sorry Andrea
The Red LED has a half bandwidth of 20nm.
The Blue LED has a half bandwidth of 22nm.
Col

#8 colinbm

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Posted 24 January 2015 - 06:43

Hi Andrea
" Col, try making a Visible photograph with the Blue LED illumination. Sometimes a UV marking will show up in violet/blue light."
You want me to do to use the Blue LED for illumination......do you want me to use a normal visible light hot mirror eg 420 - 660nm or a filter that will block the blue light, eg a 500nm long pass filter ?
Col

#9 Andrea B.

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Posted 24 January 2015 - 15:35

Just a normal visible light filter which blocks uv and ir.

We once in the past speculated that - or read that - for some flowers the UV bullseye or other markings can be seen in violet or blue light.
I don't really know if this is true, mind you. I'm just curious. :D

A violet LED would be really interesting to play with. Wonder if they are available?
Andrea G. Blum
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#10 nfoto

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Posted 24 January 2015 - 17:48

I can definitively observe "bull's eye" patterns of flowers in the cold blue light of the Nordic summers. Contrast is low, though, nothing like what the UV photography captures, but the pattern is there.

I have seen this with Taraxacum and Potentilla species, to name a few off the bat.
Bjørn Birna Rørslett, Ph.D.
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#11 Andrea B.

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Posted 24 January 2015 - 18:53

Well even in strong high-noon Visible summer sunlight down here in the lower forties and upper thirties where I hang out, we can almost always see where there is a slight change in the underlying chemistry in the bullseye area on most Rudbeckias, Potentillas, Ranunculus and the like. ;)
But, as you mention, it is quite faint.

The real surprise for me is the reverse - when strongly Visibly marked flowers become completely UV absorbing or reflective. And yet we see bees on that stuff anyway. :D

Bjørn, do you remember seeing anything about narrowband violet or blue light bringing out the bullseyes??
Andrea G. Blum
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#12 Bill De Jager

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Posted 25 January 2015 - 05:16

View PostAndrea B., on 24 January 2015 - 18:53, said:

The real surprise for me is the reverse - when strongly Visibly marked flowers become completely UV absorbing or reflective. And yet we see bees on that stuff anyway.

Honeybees are not native to North America and are certainly not the pollinator these plants have evolved for. Bumblebees and other native bees probably are in many cases, along with a variety of other native pollinators.

Edited by Bill De Jager, 25 January 2015 - 05:25.


#13 OlDoinyo

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Posted 27 January 2015 - 04:11

View PostAndrea B., on 24 January 2015 - 18:53, said:

The real surprise for me is the reverse - when strongly Visibly marked flowers become completely UV absorbing or reflective. And yet we see bees on that stuff anyway. :D

You might get some perspective on this issue by doing "bee vision" composites on these flowers in context (in the field, not merely as isolated specimens.) How do the nectar-guide areas stand out from their general surroundings (foliage, stems, etc?) The Passion-flower might be a good candidate for a visible-only marking, whereas any number of things have UV-only markings.

#14 JCDowdy

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Posted 28 January 2015 - 04:31

View PostAndrea B., on 24 January 2015 - 18:53, said:

The real surprise for me is the reverse - when strongly Visibly marked flowers become completely UV absorbing or reflective. And yet we see bees on that stuff anyway.

I have at times had similar thoughts about very UV dark flowers, and recall others making similar comments. I have enjoyed the pseudo color insect vision representations but have yet to try my hand at it. It has however occurred to me that UV dark in this context is analogous, in humans to strong absorption in the violet/blue end of the visible spectrum, resulting in what is to our eyes rather noticeable yellow. UV reflectance is likely just as conspicuous in it's absence.

#15 Andrea B.

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Posted 28 January 2015 - 14:43

I've played a lot with bee colours. Made all kinds of charts, etc. :D

But bees are not the only pollinators. And Visible or UV patterning is not the only pollination strategy.
Andrea G. Blum
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#16 Shane

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Posted 28 January 2015 - 16:52

Quote

We once in the past speculated that - or read that - for some flowers the UV bullseye or other markings can be seen in violet or blue light.
I don't really know if this is true, mind you. I'm just curious.

See spectrum http://www.beyondvis...tamination.html . This is true for the dandelion but the outer UV reflective region also absorbs in the blue (as it does for all yellow flowers). However the slight difference around 400-425nm might be observed with a narrow band blue filter.

#17 Andrea B.

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Posted 29 January 2015 - 18:38

Col's Allamanda work is going to be added to the Botanical Section. :D

********

Added: I am fascinated by the little twinkle which appears at the fusion point of the petals in some of the photographs. A delightful flower, isn't it?
Andrea G. Blum
Often found hanging out with flowers & bees.