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Comments needed for this poster [UPDATE 2017.02.21]

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#1 Andrea B.

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Posted 09 February 2018 - 20:08

Any comments, suggestions and corrections are welcomed for this poster.
This poster is meant to accompany UV photographs of pollination guides in visible, UV and UV/B/G light.

It is impossible to put everything on one small poster!! But is there enough on this poster?

One problem I am having in Photoshop is to make the edges of the flower shapes smooth. I used a "shape" in PS, but when I colored it in, the edges were all jaggy.

The shadowing around the bee will be removed because it is making the bee look like it has 12 legs!!! The bee graphic was a free download which I altered. (Added: I adjusted the bee shadow, so maybe won't remove it.)

Thank you for any help.
This JPG is 2500 px wide so it is going to get resized by the forum software.
Still, if you click it up, you can see a larger version.


Attached Image: FlowerBeeVee_Template09Fed2018.jpg
Andrea G. Blum
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#2 UlfW

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Posted 10 February 2018 - 11:50

Human Visual Peaks.

I thought that the human colour vision receptors for the longest wavelengths had a peak closer into the red area.
It is more common to talk about blue, green and red sensitivity.

This is not something I know a lot about, but a quick search found this:
http://hyperphysics....ion/colcon.html

If this is correct it might be better to say orange or even red instead of yellow.
575nm is a very red-toned yellow.

The wavelength span that we see as yellow is rather narrow compared to our red span.
http://www.webexhibi...5-humanBeeZ.jpg

Edited by UlfW, 10 February 2018 - 11:54.

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#3 Andrea B.

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Posted 10 February 2018 - 17:54

Thanks Ulf for your comment! It has helped me realize I need to replace the 3-color human vision chart -- but not because it is inaccurate.

We are commonly taught that human color vision peaks are blue, green and red. But this is wrong because the peaks lie in blue, green and yellow regions. Please see the attached chart.

I think the error has happened because the waveband having a yellow peak does have a width which covers red. But this yellow-peaked waveband also covers orange, yellow and green. Looking at the attached chart, you can see that the green-peaked waveband covers almost the same colours.

We know from the physics of light that we can construct all visible colours as long as the 3 peaks are different. So human blue, green and yellow peaks do enable construction of all visible colors in our eye/brain visual system.

This chart is from the University of New South Wales in Sydney (posted under a Creative Commons License.) Following common practice, the wave on the right is shown in red but the yellow-ness of its peak is also illustrated.
Attached Image: visionPeaks.jpg


I think that my original 3-color human vision chart above is going to probably confuse people. So I think I will probably replace it with something like the attached chart.

I got the color representation from this wavelength-to-color calculator: https://academo.org/...r-relationship/
445 nm ==> (0,40,255), almost pure blue.
535 nm ==> (112,255,0), green with just a tinge of yellow.
575 nm ==> (240,255,0), almost pure yellow.
Andrea G. Blum
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#4 Hornblende

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Posted 10 February 2018 - 19:11

In human the blue cones are far less sensitive than green and red cones.
Do we know the relative sensitivity of each bee receptors?

https://i.stack.imgur.com/5snTb.png

Edited by Hornblende, 11 February 2018 - 01:42.


#5 UlfW

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Posted 10 February 2018 - 19:12

Hi Andrea,

I was wrong about 575nm being orange.
It is almost pure yellow and your chart is correct, but possibly confusing. The peak wavelength is not the only important information.

The span we see as yellow is rather narrow compared to the colours we see as red.

My misstake was caused by how longpass-filters look.
Already a 560nm longpass is quite orange.
Stupid, I should think and verify before I post. Sorry.

If I understand things correctly the brain is also processing the difference between the green and yellow images, enhancing how we perceive red nuances.
Is that correctly undestood?
Ulf Wilhelmson
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#6 Andrea B.

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Posted 11 February 2018 - 01:38

Ulf, no apologies needed !! :) When looking at the red wave in some charts, it does appear as though the peak is a mix of yellow+red = orange. And, again, as mentioned, I do think the 3 colours I posted originally for the human peaks are going to be confusing to someone who is not more familiar with visible light wavelengths and visual receptor peaks. I'm going to replace it with a wavelength chart.

Martin, I don't recall precisely the answer to your question about the bee sensitivity. I think that the bee UV receptor is less sensitive, but I need to look at my references and confirm that.

Summary of Corrections -- so far......
1) Replace 3-color charts with wavelength charts.
2) Replace the lime-green in the bottom flower by a yellow color (which the UV/B/G filter would produce).
3) Relabel Sunflower as Rudbeckia or perhaps substitute actual flower photographs.
Andrea G. Blum
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#7 OlDoinyo

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Posted 11 February 2018 - 04:07

Your schematic "sunflower" looks more like a Rudbeckia. That's a quibble, I know, but most sunflower rays I have seen were dark almost to the tip in UV. The principle is the same, of course.

#8 Andrea B.

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Posted 12 February 2018 - 00:47

Thanks, Clark, for your comment!
There are some sunflowers which look somewhat like my schematic flower, but your point is well made. Most folks are going to think of a Sunflower as having a much larger central disc. I am thinking that either I will substitute an actual photo of a Dandelion or relabel the schematic flower as a "Black-eyed Susan".
Andrea G. Blum
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#9 Andrea B.

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Posted Yesterday, 01:58

Here is one final version of a Bee Vision poster. It does not attempt to explain everything, of course. :D
Thank you again to those who commented !! It was greatly appreciated. ;) B)

I decided the poster did not need a human vision color chart. It's all about the bee instead.

I cut out a Dandelion to use as an example because that flower is quite well known to most in North America where this poster would be used. Perhaps I should use a real bee cutout? But I rather like the cartoon bee which was an internet find under creative commons that I modified.

This will serve as a basis for other educational posters. More detail can be added or different kinds of floral UV-signatures used. This particular version will perhaps be used in conjunction with two other photographs of the Dandelion - one in Visible light and one in UV light.

Attached Image: beeChart2017022101.jpg
Andrea G. Blum
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#10 Andrea B.

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Posted Yesterday, 02:11

Nikon D610-mod + UV-Nikkor 105/4.5 + KolariU UV-Pass Filter + Sunlight
f/16 for 2.5" @ ISO-400
Attached Image: taraxacumOfficinale_uvKolari_sun_20170414wf_984pnPf216in.jpg


Nikon D610-mod + UV-Nikkor 105/4.5 + Baader UV/IR-Cut Filter + Sunlight
f/16 for 1/100" @ ISO-400
Attached Image: taraxacumOfficinale_vis_sun_20170414wf_947pnPf16in.jpg
Andrea G. Blum
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#11 Cadmium

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Posted Yesterday, 03:27

Kind of similar to the UG5 UV+Blue+Green stacks. UG5 2mm + S8612 2mm, Kuri 35mm.
Attached Image: Dandelion_UG5.jpg

#12 Andrea B.

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Posted Yesterday, 16:33

I like your close-up because it has a nice range of color - the yellows, cyans and greens all present in this Dandelion. (It is a Dandelion? Sometimes with the yellow Asteraceae it is difficult to say. Could be a Heiracium?)

I looked mine up --- used a U-330 (1.5mm) + S8612 (3.0mm) for the UV/B/G cut-out photo. The day I made that shot I was experimenting with many different filters and stacks. Typically, now, I would use a 2.0mm S8612.
Andrea G. Blum
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#13 Cadmium

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Posted Yesterday, 18:09

I think it is a grumpy morning dandelion that hasn't had any coffee yet, but I don't know for sure.
Yes, U-330 works the same, 1.5mm thick usually looks best for UG5 and U-330, stacked with
S8612 2mm is as thick as you need, any red you see is from white balance, not from actual visual red.
Here is the full size pic, out of cam and white balanced. I think it is a dandelion, I think they tend to close up at night?

By the way, the date of this shot is 4/18/2012, my first tests of UG5 stacks for flowers. Been a while.
Attached Image: BUZ_U_1_comp.jpg

Edited by Cadmium, Yesterday, 18:16.


#14 Andy Perrin

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Posted Yesterday, 18:12

I like the colors here also (post-WB). I nominate the dandelion as the Official Mascot of UVP.

#15 Cadmium

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Posted Yesterday, 18:25

Here are the BG3 + S8612 and BG25 + S8612 stack versions of the same flower.

Schott BG3 stack
Attached Image: BG3_850.jpg

Schott BG25 stack
Attached Image: BG25_850.jpg

#16 Cadmium

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Posted Today, 08:27

View PostAndy Perrin, on 22 February 2018 - 18:12, said:

I like the colors here also (post-WB). I nominate the dandelion as the Official Mascot of UVP.

Andy, I think there should be a 'top ten' list of best UV target pattern flowers.
I vote for the Dandelion also, because it seems most abundant, and long seasoned. My favorite is Rudbeckia, of course, but it has a later blooming season.
I think other people who are more versed in the UV flowers could suggest more for a list, and I think such a list would be valuable for those of us who are not as UV flower experienced.