Plant autofluorescence at dusk

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Lou Jost
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Plant autofluorescence at dusk

Post by Lou Jost »

I made a video about plant fluorescence for the Natural History Institute. The first part might be a little boring for most of you, but the second half includes some video of fluorescing plants in nature.
https://www.youtube.com/watch?v=WjU_IOWZB2U

iconoclastica
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Re: Plant autofluorescence at dusk

Post by iconoclastica »

Wow, that's something I 'd like to see in reality! I wonder how our temprate woods will look like.
It also shows I have no memory for human faces - I wouldn't have recognized you even if you'd knocked at my door.
BTW, the Elaphoglossum at 10:50 is not, they don't have discrete sori. Probably a polypodioid (Niphidium[/]).
--- felix filicis ---

Adalbert
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Re: Plant autofluorescence at dusk

Post by Adalbert »

Hello Lou,
Very interesting story!
BTW, did you assemble the UV flashlight yourself?
Best, ADi

rjlittlefield
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Re: Plant autofluorescence at dusk

Post by rjlittlefield »

This is very cool!

Do you have a parts list for the flashlight, filters, and protective goggles?

--Rik

MarkSturtevant
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Re: Plant autofluorescence at dusk

Post by MarkSturtevant »

Very cool! There are lots of inexpensive led UV flashlights one can buy. I got mine from Amazon. When I go out at night looking for critters, its also very fun to see all the red fluorescent colors from the leaves. A familiar world is fairly transformed.
Mark Sturtevant
Dept. of Still Waters

Harald
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Re: Plant autofluorescence at dusk

Post by Harald »

Hi Lou Jost,

Great video on UV light in the field

I have both the Convoy S2 and C8. Great light, but one need to have the ZWB2 filter installed to avoid the white light.
Use the mainly for fluorescence minerals

Thanks for sharing :D
Kind Regards
Harald

Lier Fotoklubb / NSFF
AFIAP / CPS
BGF / GMV
http://www.500px.com/blender11

Lou Jost
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Re: Plant autofluorescence at dusk

Post by Lou Jost »

Hi all, thanks for the kind comments. I've been in the air all day yesterday returning to Ecuador.
It also shows I have no memory for human faces - I wouldn't have recognized you even if you'd knocked at my door.
BTW, the Elaphoglossum at 10:50 is not, they don't have discrete sori. Probably a polypodioid (Niphidium[/]).
Thanks for that correction, Iconoclastica. This was a giant (1m+ frond length) tongue-like frond without pinnae, and I had always assumed these were all Elaphoglossum.

My memory is also terrible, and not just for faces. Have we met in person?
Wow, that's something I 'd like to see in reality! I wonder how our temprate woods will look like.
I think the experience would be very similar in temperate forests. Just need a strong enough and pure enough source of 365nm UV light.
BTW, did you assemble the UV flashlight yourself?
Adalbert, just a bit, it is a commercially available C8 (though these apparently do not all use the same LED) modified by the seller to have a constant output until the batter dies. I added a cheap magnifying glass in front, and then a really good UV-pass filter on top of that, in case of autofluoresecence of the magnifying glass. If you get really close to the subject, this si strong enough to excite visible autofluorescence even at noon in the shade.
Do you have a parts list for the flashlight, filters, and protective goggles?
Glad you liked it Rik. I can do that list when I get back to my home in a few days.
There are lots of inexpensive led UV flashlights one can buy.
Mark, I highly recommend the two-battery C8 rather than the earlier Convoy flashlights. I find they all need some added filtration for good photographic results. Besides a better UV-pass filter on the flashlight, I use a Zeiss T* UV-cut filter as a barrier filter on the taking lens.
I have both the Convoy S2 and C8. Great light, but one need to have the ZWB2 filter installed to avoid the white light.
Harald, thanks, and yes, additional excitation and barrier filtration is needed for best results, see my comment to Mark.

I should emphasize that this is a 365nm UV source; there are longer-wavelength UV lamps available but these are less "exciting". The excited colors are not necessarily the same when using different wavelengths of UV. For example, some scorpions glow yellow under 380-390nm lights but are bright blue in 365nm light.

iconoclastica
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Re: Plant autofluorescence at dusk

Post by iconoclastica »

Lou Jost wrote:
Sat Jun 26, 2021 7:28 am
My memory is also terrible, and not just for faces. Have we met in person?
Ha, yes, we dined together in Baños a little over ten years ago, when I was on the giant-horsetail hunt. I did something for the Spruce memorial too, but I only remember compiling a species list.
--- felix filicis ---

Lou Jost
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Re: Plant autofluorescence at dusk

Post by Lou Jost »

Ah yes! And those giant horsetails have still not been found. I've been keeping an eye out for them...

What are you doing now?

Lou Jost
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Re: Plant autofluorescence at dusk

Post by Lou Jost »

I should add that royal blue light may excite more fluorescence than UV light. See this blog post and graphs by Charles Mazel of Nightsea:
https://nightsea.com/articles/blue-ligh ... orescence/
However, it is more difficult to photograph because you need very good excitation filters and barrier filters (nearly-monochromatic lasers can reduce the need for excitation filters).

jmc
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Re: Plant autofluorescence at dusk

Post by jmc »

Very nice. Have taken the 365nm torch round the garden at night, and its amazing how things look with the fluorescence.
Jonathan Crowther

Lou Jost
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Re: Plant autofluorescence at dusk

Post by Lou Jost »

Yes, it really is amazing!

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