• Ultraviolet Photography
  •  

Bees see blue halo

13 replies to this topic

#1 Damon

    PineyPower

  • Members(+)
  • 419 posts
  • Location: NJ Pine Barrens

Posted 12 November 2017 - 05:12

Greetings old and new friends.
This new research reminds me of iridescence from conical cells.

https://www.sciencedaily.com/releases/2017/10/171018132826.htm


-Damon

#2 nfoto

    Fierce Bear of the North

  • Owner-Administrator
  • 1,864 posts
  • Location: Oslo, Norway

Posted 12 November 2017 - 10:03

Scientists obviously are capable of re-inventing, or rather re-discovering, the wheel as it were. Iridescence originating from conical cell structures is not new as such. Thus, we see it everywhere in UV photography of floral structures. I'm surprised that such a pretentious journal as 'Nature' would print this article without acknowledging such basic phenomena.

On a tangential note, I'm not surprised they coined a new, superfluous phrase ('blue halo') as this underlines their 'new' finding.
Bjørn Birna Rørslett

#3 Alaun

    Member

  • Members
  • 171 posts

Posted 12 November 2017 - 11:03

As I understand it, they were not into conical cell structures (they have a couple of references to them) but into cuticular structures about one order (10x) smaller. The optical effect might be similar. Special interest they focus on is the disorder of the arrangement of these structures.

You can find SEM pictures they have taken and used in their research at the Open Science Foundation platform (https://osf.io/4tpp2/files/)
Werner

#4 nfoto

    Fierce Bear of the North

  • Owner-Administrator
  • 1,864 posts
  • Location: Oslo, Norway

Posted 12 November 2017 - 19:04

"Disorder" is exactly what we see with regard to the distribution and manifestation of conical cell structures. Actually this might differ not only within parts of a flower, but also from the neighbours of the same species. That this leads to iridescence and that this effect is dependent on angle of incidence of incoming light, can be verified by UV video. I suspect smaller-scaled structures might influence wavelength (?) of optical phenomena, though, but the cell structures we see on petal surfaces certainly operate in UV.
Bjørn Birna Rørslett

#5 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 5,172 posts
  • Location: USA

Posted 13 November 2017 - 19:50

Damon, hi there !!! I wondered what happened to you!? There are lots of interesting posts to catch up on, so I hope you enjoy them. If you are still experimenting with UV and Fluorescence, please do post something. Still remembering those fluor mushrooms!! So cool!!
Andrea G. Blum
Often found hanging out with flowers & bees.

#6 Damon

    PineyPower

  • Members(+)
  • 419 posts
  • Location: NJ Pine Barrens

Posted 14 November 2017 - 04:02

Hi Andrea, yeah it's been too long! I took a short sabbatical lol. Once you get into all this it never really leaves you though does it?

I have been doing a fair amount of Fluorescence. Just like my Blak Rays I went overboard and bought 15 Convoys and enclosed 12 of them with rubber bands into 1 giant beam. It's pretty amazing. I can see halfway across my yard lol. And my shutter speeds are much higher FWIW.
Glad to see you and Bjørn are still doing ok.

Been shrooming some as well. Fluorescence video is pretty cool. You can shine a visible light on a shroom and as you take that light away you bring in UV and then reverse and so on. The mushrooms appear to be just seemlessly transforming into glowing shrooms. It's been pretty fun. These convoys are a serious bonus and work really well.
Also, I came across a pretty darn useful discovery. I will post it under UV Fluorescence. BTW my stock/unmodified Canon 1D mark IV is still working well for UV, Fluorescence, Visible, and IR.

Been thinking of experimentinga little.
Years ago I remember aiming a laser thermometer across a Gazania in full sunlight and when it hit the UV signature part (black) the temperature went up. It would be wise for an insect to stay there to warm up quicker in the morning maybe. Anyway, I don't know exactly how to do it yet but want to use the same thermometer on live things that Fluoresce and see if they are hotter when fluorescing compared to a similar organism that does not Fluoresce but is also getting hit by the same UV light. My example is flawed but you can see where I am trying to go. Should be fun.

I will look around and see what everyone has been up to.
-D

Edited by Damon, 14 November 2017 - 04:02.


#7 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 5,172 posts
  • Location: USA

Posted 14 November 2017 - 20:59

Damon, give us a snapshot of that 12-piece Convoy UV-Led gigantor construction !

Also, remember the discussions about correct white balance under black lights? Turns out there is a solution. Has to do with a certain kind of white fluorescent paint. Rather, paint which fluoresces white under black light.

So an enterprising fellow designed a white card for black light using some kind of this paint. Here are my experiments with it. I tried to find the best setting for those who do not have the useful but rather pricey set of Target-UV and UV-Grey, but I did not find a good one. K10000 seemed to be the closest. Further experimentation is needed. Now that winter is arriving, perhaps I can get back to this.

Exp 1: First Look at Target-UV & UV-Grey for UVIVF [See Post 7]

Exp 2: Target-UV with Stock Cam, Unfiltered Lens & Unfiltered UV-LED

Exp 3: Target-UV with Stock Cam, Filtered Lens & Filtered UV-LED

Exp 4: UVIVF White Balance with the UV-Grey Target, Stock Cam/Lens
Andrea G. Blum
Often found hanging out with flowers & bees.

#8 Damon

    PineyPower

  • Members(+)
  • 419 posts
  • Location: NJ Pine Barrens

Posted 15 November 2017 - 05:27

Wow that is impressive research there Andrea. Congrats on doing that!
When I set my software to 10000K some of the blue goes away in my caterpillar shots. But the blue is so pretty... :)
When looking at UV Fluorescence with my bare eyes (and poly goggles), I wonder how my eyes are white balancing it?. Surely different than a moth?


OK so here are some unedited cell phone pics of the convoy cannon.
OFF
Attached Image: 14 Convoy S2 UV light cannon©DNoe.jpg

ON (Looks like one of them is not turned on)
Attached Image: 14 Convoy S2 UV light cannon_©DNoe.jpg

On Wall ~ 12 ft away. It was a much larger spread and brighter than the cell phone could capture. Nearly covered the wall. If too bright, I just click some off. I can see some mushrooms glowing at about 40 ft. away lol.
Attached Image: 14 Convoy S2 UV light cannon_poor cell phone pic 12 ft from wall©DNoe.jpg

-D

#9 Andy Perrin

    Member

  • Members(+)
  • 868 posts
  • Location: United States

Posted 15 November 2017 - 05:50

Wow, that is a serious amount of UV. I hope you are doing something to minimize exposure! Have you tried to estimate how intense that is relative to sunshine?

#10 Damon

    PineyPower

  • Members(+)
  • 419 posts
  • Location: NJ Pine Barrens

Posted 15 November 2017 - 06:13

In winter I need more vitamin D (just kidding)
I always wear 100% Polycarbonate goggles. I placed them on my UV meter and nothing gets through. And it rarely hits my skin.
I am pretty sure these lights would bury the needle on my meter. Is there another way to measure what your asking?

I can try to induce Fluorescence during the day and see if it overpowers regular afternoon sunlight. I will experiment on some known fluorescing inanimate objects.

Most bugs I hit with it move away quickly, even at a few feet away. Although I had a katydid that didn't move at all. I mainly use the cannon on mushrooms and to help initially to locate stuff.. I don't want to hurt anything. Hasn't damaged any shrooms yet either. I have a couple more single lights as well I also carry around. The batteries I have in these lights last a long time. It's like walking around with a regular decent visible light flashlight.

-D

#11 Andy Perrin

    Member

  • Members(+)
  • 868 posts
  • Location: United States

Posted 15 November 2017 - 17:01

Oh, I was thinking just trying to estimate how many W/m^2 from one of them at close range and then multiply by how many beams overlap. Then compare that to sunshine. Not a precise measurement, truly an estimate.

Edited by Andy Perrin, 15 November 2017 - 17:02.


#12 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 5,172 posts
  • Location: USA

Posted 15 November 2017 - 22:13




Holy wow !! That is quite a convoy of Convoys. And you do need an industrial strength rubber band. :lol:




When looking at UV Fluorescence with my bare eyes (and poly goggles), I wonder how my eyes are white balancing it?.

Well, there's the problem.
Usually we make UVIVF fotos in the dark. In the dark or in very dim light our eyes would shift to their scotopic (rod) vision which certainly alters the way we perceive colours and saturation of colours. Then there is the effect (or not) on colour due to wearing the necessary goggles when handling UV-Leds. And finally, we do have that UV-Led light inducing a visible glow, so maybe our eyes are not completely using scotopic vision while shooting UVIVF. If the emitted visible light is strong enough, we could be using a mix of rods & photopic cones. Anyway all this wreaks havoc on the colour perception of visible fluorescence.

(nothing new in all that for some of you...we've discussed it before....just recapping what we know for newb readers)

Now, do we trust what our eyes saw in the dark under the blacklight when trying to decide how best to present the colours in UVIVF photos? Turns out it is best not to because human color memory is very poor. Oh sure, we can remember that we saw a red chlorophyll glow from some fluorescent leaf or stem, but if presented with 10 different red color patches we will have a very tough time picking out the one which best matched the red fluor we just saw.

So, it makes me happy that there is such a thing as a white fluorescing target to use for UVIVF because it will nail down some version of the colour glow I saw in the dark and will help ensure some uniformity of results across different photographic platforms. For scientific documentary photography that is mandatory. And the Target-UV works really well.

For artistic or informal UVIVF photography, I think you can probably still just go with a memory adjustment to your Daylight, Auto or K10000 setting and aim to get your visible fluorescence as close as possible to what you "saw". I say this because currently such fluorescent targets for white balance under black light are currently priced for the professional, scientific user who has someone else's money to spend. :rolleyes:

Eventually someone will find a source for fluorescent white paint of some kind and such targets will become less expensive - analogous to the way we use PTFE in place of Spectralon.
Andrea G. Blum
Often found hanging out with flowers & bees.

#13 JMC

    Member

  • Members
  • 135 posts
  • Location: UK

Posted 15 November 2017 - 22:48

This any good for the fluorescent white paint, Andrea?

http://www.glowtec.c...white-UVR-2.htm

#14 Andrea B.

    Desert Dancer

  • Owner-Administrator
  • 5,172 posts
  • Location: USA

Posted 16 November 2017 - 00:31

Hard to say without trying it. Many of the white fluorescent pigments I've seen so far tend to have a slight blue cast.

They have an interesting gallery!
http://www.glowtec.c...V-R-gallery.htm




I'm looking for a US seller of "UV White" paint to order and test. We had some links somewhere?
We need to figure out what to paint - paper, plastic, wood, cardboard??

The nice British Glowtec paint would cost me a bit too much for a casual test due to cross-Atlantic shipping charges and possible import fees!

Here's a link I found, but they are out-of-stock for this brand: https://www.blacklig.../items/WF161191




As noted by one UV paint seller:
True white is difficult to achieve with normal UV pigments, this is our best shot without going with the ultraexpensive True Balance white.
http://www.fxsupply....uv/uvpaint.html
Andrea G. Blum
Often found hanging out with flowers & bees.