• Ultraviolet Photography
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Solanum tuberosum [Potato]

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#1 msubees

    Zach Huang

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Posted 26 June 2015 - 17:52

Huang, Z.Y. (2015) Solanum tuberosum L. (Solanaceae) Potato. Flowers photographed in ultraviolet, visible light and simulated insect vision. http://www.ultraviol...berosum-potato/

East Lansing, Michigan, USA
24 June, 2015
Cultivar in a vegetable garden.

Comment:
Photographs taken in the order of visible light, ultraviolet, and simulated insect vision. UV signature is almost uniformly UV-absorptive, yet simulated insect vision shows a cyan flower with a dark center. This to me suggests the anthers are "darker" under UV although the current UV photo does not reveal this.

Reference:
1. Wikipedia (26 June 2015) Potato. Wikimedia Foundation, San Francisco, CA.

Equipment [Sony Nex7 + El Nikkor 80mm f/4.5 old format]

1. Visible Light [f/8 for 1/30" @ISO100, S8612 (2 mm thick), natural light]
Posted Image

2. Ultraviolet Light [f/8 for 30" @ISO100, S8612 (2 mm thick) and ZWB1 (1.5 mm thick), natural light]
Posted Image

3. Simulated Insect Vision [f/8 for 1.3" @ISO100, S8612 (2 mm thick) and UG 5 (1.5 mm thick), natural light]
Posted Image

#2 Andrea B.

    Desert Dancer

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Posted 26 June 2015 - 22:08

Nicely composed photographs. I like seeing the flower on the white background with the false coloured shadows.

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Have I remembered to mention to you (and others) that you should remember to embed an sRGB colour space into the file when you are saving a JPG for web viewing? Most browsers have become better at colour awareness, but not every viewer bothers with such settings. Thus we typically embed sRGB iEC61966-2.1 so all viewers can see the proper colours of a photograph.

When I look at your UV photo in one of my editors, it appears much more cyan than it does here on the webpage. What colour space did you embed for that one?

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This to me suggests the anthers are "darker" under UV although the current UV photo does not reveal this.

Why would you think that the anthers absorb more UV than the corolla?
Andrea G. Blum
Often found hanging out with flowers & bees.

#3 msubees

    Zach Huang

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Posted 27 June 2015 - 16:04

Andrea,

Thank you! I checked mine, all jpeg were rendered as adobe RGB, I have now changed to sRGB-1966-2.1. I will replace all my old jpegs. I have replaced the UV for patato, please check to see if it is now different... I did not remember that you mentioned a color space for jpegs here, but perhaps I should have known? All my D700 photos were set to sRGB. I am still new to PhotoNinja...

Zach

#4 Andrea B.

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Posted 27 June 2015 - 18:07

The UV foto now looks correct on the web page.

If every viewer in the world knew how to set colour management features in their browser, then we would not have to worry about what profile we embed in our web photos. Perhaps good colour management will someday be a universal, default browser feature.
Andrea G. Blum
Often found hanging out with flowers & bees.

#5 msubees

    Zach Huang

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Posted 27 June 2015 - 19:44

Regarding the reason why I thought the anther must be absorbing more UV than the petals, I thought the insect vision version is dark in the center. But perhaps it could be due to the yellow in visual + UV color --> darker green than the petals? On the UV, it is rather uniform between the anther and corolla. So I was expecting that the insect vision version will be similar in color between corolla and anther.

it still escapes me why when under UV it is dark, sometimes it is green, and other times it is cyan under insect vision...

Edited by msubees, 28 June 2015 - 14:24.