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Playing with a bowl of water , fake flower cotton and water droplets.

21 replies to this topic

#1 Craigk79

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Posted 13 July 2021 - 06:57

UV flash used in dark room on the flower to get uvivf shot.. This is cool. Will have to try it with some real flowers.

Attached Image: _OEC8372.jpg

#2 colinbm

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Posted 13 July 2021 - 07:10

That is pretty sexy....

#3 Andrea B.

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Posted 18 July 2021 - 18:45

Craig, I can't figure this one out??

The flower is reflecting in the water droplet? But some water droplets are hanging down and some are hanging up ???

However it it, it turned out very interestingly. :smile:
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#4 Craigk79

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Posted 20 July 2021 - 12:23

View PostAndrea B., on 18 July 2021 - 18:45, said:

Craig, I can't figure this one out??

The flower is reflecting in the water droplet? But some water droplets are hanging down and some are hanging up ???

However it it, it turned out very interestingly. :smile:

There is a flower for the background. The uv flashes are on it. There is a bit of cotton going across over the top of water with the droplets on it. The reflection from the flower and the droplets can be seen plus the refraction of the flower in the droplets. :)

View Postcolinbm, on 13 July 2021 - 07:10, said:

That is pretty sexy....

Thank you..

#5 dabateman

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Posted 20 July 2021 - 14:39

View PostCraigk79, on 20 July 2021 - 12:23, said:



There is a flower for the background. The uv flashes are on it. There is a bit of cotton going across over the top of water with the droplets on it. The reflection from the flower and the droplets can be seen plus the refraction of the flower in the droplets. :)



Thank you..

Thank you for the description. You have some fun science going on in that image.

It gives me an idea that I would most likely never do, but would be fun.
Line up a bunch of different transmission resins on a string. Then photograph the UV reflectance of a flower. The various UV cut offs of the resin "lenses" on the string would give the same background flower various colors. Could be quite fun with the right subject and light.

#6 Craigk79

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Posted 21 July 2021 - 08:36

View Postdabateman, on 20 July 2021 - 14:39, said:

Thank you for the description. You have some fun science going on in that image.

It gives me an idea that I would most likely never do, but would be fun.
Line up a bunch of different transmission resins on a string. Then photograph the UV reflectance of a flower. The various UV cut offs of the resin "lenses" on the string would give the same background flower various colors. Could be quite fun with the right subject and light.

Sounds very cool

#7 colinbm

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Posted 21 July 2021 - 08:48

Dave, what are " transmission resins " please ?

#8 Andrea B.

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Posted 21 July 2021 - 20:43

Craig, thanks! Suddenly it all popped into place. It's funny how sometimes we don't "see" what we are seeing. :lol:
Andrea G. Blum
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#9 dabateman

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Posted 21 July 2021 - 20:57

View Postcolinbm, on 21 July 2021 - 08:48, said:

Dave, what are " transmission resins " please ?

Colin I found this idea interesting:
https://petapixel.co...olds-and-epoxy/

Then went down the rabit hole looking into various resins and if transmission curves existed for them. There are some that might work in UV.

The idea merged here is you only need a drop on a line as a lens. Not a huge one for a large format film camera.

Edited by dabateman, 21 July 2021 - 20:59.


#10 Stefano

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Posted 21 July 2021 - 21:16

If I understand, you can make resin lenses which are UV-transparent and show a flower with its natural UV false colors, and also resin lenses with a high cut-off (like 380 nm) that would probably appear lavender and make the flower appear lavender. A lens made of U-glass would appear yellow. Is that the concept?

#11 dabateman

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Posted 21 July 2021 - 22:27

Yes Stefano has it.

But thinking about this again, you might be able to keep it simple and just crack out your old chemistry set.
Mix copper sulfate or various other common chemicals with various concentrations in water and carefully drop them on to the line to look for color differences.

Maybe more art than knowledge. But I most likely wouldn't do this.

This does however offer a quick test with various resins to see if they pass the full uv floral signature.

#12 colinbm

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Posted 22 July 2021 - 01:18

Dave, Brilliant idea, lots of 'food for thought'.

Stefano, " A lens made of U-glass would appear yellow. "
I am not getting it, in my mind, this yellow ?

But here is an example I just saw today too....?
This is from

Nabeel Ashraf from Fluorescent Minerals FaceBook post.....
He says that..... "
The Quartz is not fluorescent. The UV light pointed at it from the top makes it appear so."



Posted Image

Edited by colinbm, 22 July 2021 - 01:19.


#13 Stefano

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Posted 22 July 2021 - 01:28

View Postcolinbm, on 22 July 2021 - 01:18, said:

Stefano, " [color=#282828][font=helvetica, arial, sans-serif]A lens made of U-glass would appear yellow. "
I am not getting it, in my mind, this yellow ?
If you take a UV photo of a piece of ZWB1/ZWB2/U-340 etc it will appear UV-yellow.

See how the U-340 on a Convoy S2+ torch appears greenish-yellow in UV: https://www.ultravio...dpost__p__44962

Imagine a lens made of the same glass.

#14 colinbm

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Posted 22 July 2021 - 01:59

I am not getting yellow ?

#15 Stefano

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Posted 22 July 2021 - 02:01

That's a bit odd. Did you try this with sunlight/flash, broad filtration and a proper white balance?

#16 colinbm

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Posted 22 July 2021 - 02:09

Obviously I am doing something wrong ?
Photograph a U340 filter with sunlight behind it...?

#17 Stefano

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Posted 22 July 2021 - 02:22

Another image I took (ZWB1, 3 mm thick): https://www.ultravio...attach_id=22120
Original topic: https://www.ultravio...g-story-to-tell

#18 colinbm

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Posted 22 July 2021 - 09:21

I must be doing something wrong ..... ?
I shine the light at or through the Quartz or ZWB1 & it appears clear to the full spectrum camera ?

#19 Stefano

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Posted 22 July 2021 - 10:54

Quartz is ~100% transparent in UV, so it has no color. ZWB1/ZWB2 glass peaks at 340-360 nm, and that gives it its yellow tint.

#20 Stefano

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Posted 22 July 2021 - 11:02

If you are using a 365 nm LED for example, the image you get doesn't show much color. If you use sunlight or a full-spectrum flash you will get more colors.