Moss peristome (not fluorescing)

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Beatsy
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Location: Malvern, UK

Moss peristome (not fluorescing)

Post by Beatsy »

This was going to be a UV fluorescence image but the peristome fluoresced very weakly and the extraneous light frequencies pretty much swamped it anyway. I tried to "filter" the image by knocking out the blue channel, but the violet end of the spectrum still obscured what little red fluorescence there was. Seems I'll have to wait for the slow-boat to bring my 365nm bandpass filters after all. Oh well, here's the "vis version" to be going on with.

20x mitty on 135mm tube lens - dmap stack of 100 images retouched with pmax version - full frame cropped square.

Edit: uploaded correct picture (no retouch artefacts)

Image
Last edited by Beatsy on Tue Feb 14, 2017 9:52 am, edited 1 time in total.

banania
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Joined: Mon Sep 16, 2013 9:01 am

Post by banania »

Looks like you have the beginnings of a spore capsule (sporangium, spore bearing capsule) of Fire Moss, Ceratodon purpureus, or maybe some other closely related species. Once it ripens the lid or operculum covering the mouth or stoma will fall off and reveal the peristome or peristomes as there is either one or two of these teeth-like structures quarding the spores inside the capsule.

I am growing some mosses, including Fire Moss, for photography purposes, and seeing your photo just checked the fluorescence of Fire moss spore capsules under 365 and 254 nm and these wavelengths do not seem to excite luminescence, or at least it is very faint. But the spore capsule of Fire Moss (and many other mosses) do have a strong glow (green, yellow, red) in visible light. I am not sure which wavelenghts are best activators but I believe it might be blue light as there is commonly a very strong green glow and Stokes shift does not go form lower energy levels to higher. So warm lights weak with blues are not good here. I have been using full spectrum lamps (5500K) and that activates the daylight luminescence nicely and strongly.

I could post an image as an example, but I don't want to post it in your thread. Maybe I'll create a new thread and post it there as I am not sure about the rules of posting here.

Henri

Beatsy
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Location: Malvern, UK

Post by Beatsy »

Thanks Henri,

Last time I posted "sporangia" it turned out to be "peristomes", so this time I called it "peristome" and it was "sporangia". Finally - I've got it :)

Go ahead an post your pics here. I've no issue with "top posting".

Cheers
Beats

Edit: This is prolly a silly question, but how do you "see" daylight fluorescence?

banania
Posts: 152
Joined: Mon Sep 16, 2013 9:01 am

Post by banania »

Ok, thanks, spore capsule with daylight fluorescence

Image

This is not Fire Moss but Plagiomnium affine (Many-fruited thyme-moss). I have some images of Fire moss as well, but this one is better as an example for (non-uv) fluorescence.

"Seeing daylight fluorescence" is not really possible until one realizes that such a thing exists and is not uncommon. There is a glow usually involved and the colors are strangely vivid as if coming from the inside etc, but proving the luminescence in particular cases would require tests and equipment.

Here I have used fullspectrum daylight lamp (CRI 94, 5500K) and also a linear polarizer filter attached to camera (but not crosspolarized or any other tricks).

Nikon 10X 0.25 infinity + 200mm tube lens.

Pau
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Post by Pau »

Very nice pictures!

Still not understanding what you call "daylight fluorescence" in your context. Sure, white light induces fluorescence (it has blue and green and both two excite chlorophyll), I sometimes use a white 4000k or 6000k LEDs and they work well for blue excited fluorescence but to be able to see it I need to use excitation and emission filters. Fluorescence is much weaker than excitation light reflection so it is not visible if not filtered.
Is possible that you're actually just seeing darkfield effect?

What kind of 365nm bandpass filters have you ordered?. I have 365/10 "line selection" filter intended to be used together with a more generic UV excitation filter and it cuts too much of the excitation UV light, likely because the LED spectrum is much wider, still I need to test it with my new bought Nichia LEDs.
Pau

Beatsy
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Location: Malvern, UK

Post by Beatsy »

Pau wrote:...What kind of 365nm bandpass filters have you ordered?
They're out of stock where I ordered mine from, but these are the same

http://www.ebay.co.uk/itm/282218892465? ... EBIDX%3AIT

Dead cheap - but I figured I could stack a couple if the bandpass is too wide. Just the right size for the front of the Convoy S2+ torches.

banania
Posts: 152
Joined: Mon Sep 16, 2013 9:01 am

Post by banania »

Pau, if the absortion wavelength and emission wavelength are both in the visible part of spectrum then it is daylight fluorescence, It is very common in minerals, In the context of plants it is called biofluorescence but daylight fluorescence is used in the wider sense comprising not only proteins and such but other stuff also like minerals.

Mostly daylight fluorescence is washed out by sunlight or other strong lights and can't be visually differentiated from reflected or transmitted light, but it is often there as a factor and produces faint or strong glows and deepens colors. If you take the absortion wavelenght away vivid colors and glows change to dull colors.

UV fluorescence is a well and widely known phenomena and a kind of paradigmatic fluorescence as it is so easy to discern, whereas daylight fluorescence is much less known. But I must admit this is mostly based on my own experiments, like playing with monochromatic lights, I don't have any theorethical education on this stuff to lean on.

abpho
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Post by abpho »

Beautiful work Beatsy. This is what I'd expect from a Mits 20x.
I'm in Canada! Isn't that weird?

ChrisR
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Post by ChrisR »

Very nice subtle lighting.
Not sure about the daylight fluorescence.. If the green stuff is chlorophyll A or B, it doesn't emit in green according to any graph I've seen :?
Chris R

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