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Some favourite UVF images

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#1 Adrian

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Posted 26 March 2020 - 10:34

Image 1: Mould growing on water damaged foam board
2: A mouldy Satsuma in a bowl.
3. Carnivorous pitcher plant Nepenthes fascia. The rim (peristome) was found to fluoresce as late as 2011. Still lots to learn!

Attached Images

  • Attached Image: mould on foam board.jpg
  • Attached Image: Satsuma mould.jpg
  • Attached Image: N. fusca UVF.jpg

Adrian Davies
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#2 Stefano

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Posted 26 March 2020 - 11:08

The second image (satsuma) is very interesting. Nice way to spot mould.

Edited by Stefano, 26 March 2020 - 11:11.


#3 Andy Perrin

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Posted 26 March 2020 - 14:26

I like all of them, although the “old Apple logo” satsumas are a standout.

#4 Bernard Foot

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Posted 26 March 2020 - 14:48

Liked all of your "Some favourite images" posts.

I've only just started dabbling with UVIVF photography (using multiple flashguns with ZWB1 filters plus an S8612 on an unmodified (i.e. NOT full spectrum) camera). Results in general terms are a bit like your last image of Nepenthes fascia. Am I right in assuming that the while the bright blue stuff is obviously UVIVF, the rest of the image (purply-red) is actually not caused by fluorescence but is the result of light leak from the light source which is creating a simple reflected light image?
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#5 Adrian

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Posted 27 March 2020 - 10:20

Bernard
I have a fairly light tight room, and use a Hoya U-340 filter to remove any visible light from the LED torch. Very low level fluorescence?
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#6 Bernard Foot

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Posted 27 March 2020 - 16:27

I just use a room with the curtains drawn. Because I'm using flash, shutter speed is 1/200 so the ambient light doesn't register.

However, this is what I THINK is happening - and it COULD apply yo your torch too, depending on what its output spectrum is.

The brightness of the fluorescence is quite low, so it is easy for it to be contaminated by the small amount of light leaking through the filter over the light source.

I think there may also be a secondary factor - the fluorescent light being generated is illuminating the rest of the subject.

The reason I think this might be happening is that if you look at purply stem in your shots, the colour of the markings are similar in both the UVIVF and visible shots. I notice this happening a lot, where the colour and markings in the fluorescent image are suspiciously similar to visible. So I'm not convinced I'm getting a pure fluorescent image - but a hybrid fluorescent/visible image. Example below.

It may need the exposure being reduced to suppress the leaked visible image (if that it indeed what is happening) - but then the fluorescence image will be very weak too.

Attached Image: UVIVF 023 Alstroemeria R.jpg

Attached Image: UVIVF 023 Alstroemeria Vis R.jpg
Bernard Foot

#7 Andrea B.

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Posted 27 March 2020 - 18:26

Yes, the fluorescence does illuminate other parts of the floral subject. I think of it as a mostly unavoidable side-effect. (That is, if the illumination and the lens are suitably filtered and there is no ambient light.)
Andrea G. Blum
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