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Poinsettia


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Noe, D. 2014. Euphorbia pulcherrima Willd. ex Klotzsch [Euphorbiaceae] Poinsettia. Plant photographed in visible and ultraviolet-induced visible fluorescence (UVIVF). http://www.ultravioletphotography.com/content/index.php/topic/1142-poinsettia/

 

Sweetwater, NJ

6 December 2014

Ornamental Species

 

Comment: One can barely travel anywhere around here in the US this time of year without running into the poinsettia. Grocery store, gas station..they're everywhere!

 

$3 and I had myself a specimen to test under UVIVFL.

There is a bit of mystery and myth surrounding these holiday favorites. I believe it is still today a misunderstood plant (and a bit weird). Here are a couple morsels I got from about flowers dot com, which list all the research sources. To each their own but I am not too worried.

 

--Don't let your toddlers near them because if they eat the leaves they will be poisoned--

--well maybe, but only if they eat about 500-600 leaves all at once

 

--The plant is deadly to your pets if they ingest it--

--at the most they could get an upset stomach.

 

It's pretty neat that the red we see is not the flowers at all--they are just colored bracts/modified leaves.

 

Anyway, I took a close up of the flowers. I apparently waited too long and all had gone through their cycle but one. So I took it anyway. I also cut into one of the leaves and it started bleeding sap, a milky white latex kind of sap. There are many plants that also do that. Well guess what...it fluoresces too! Quite a bit actually. I am going to zoom in on a drop and check it out asap.

 

Visible: Canon 30D Unmodified, Canon EF100mm f/2.8 Macro USM , Halogen & LED light, 1.3 s @ f/8 ISO 200, No Filters.

post-51-0-36780200-1418002015.jpg

 

 

UVIVFL: Canon 30D Unmodified, EF100mm f/2.8 Macro USM, 3 Blak-Rays B-100AP, 3.2 s @ f/8 ISO 320, No Filters.

post-51-0-74268900-1418002440.jpg

 

 

Diptych

post-51-0-90418700-1418002511.jpg

 

-D

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E. Pulcherrima has a history connected to where I live. It was named after Joel Poinsett, who was from a Charleston family who had members living in upstate South Carolina and even up the escarpment into North Carolina. He was responsible for popularizing this plant in the United States.

 

The little flowers have puzzled me--they look like a cup of stunted sepals out of which protrudes a mass of anthers. Are there no petals at all? Where are the pistils?

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The Poinsettia is an eyefull in UVIVF :)

We have then locally down-under & fresh in bloom, though they are getting too much night light at home here, so I'll find some others & give them a go & see.

Col

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Col--It's almost alien looking.

When I get a fresh one I want to zoom in onto one of those round little pistil things at the top of that tall structure. I want to know what the heck is going on in there. I think they might be full of pollen or something like that. Another nice mystery.

 

-D

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Oh so many things. You promise ice cream, people wait & nothing happens. That's all I can think of now but rest assured the list is long. I am making a list and checking it twice.

 

BTW--that focuser is the bomb!

 

-D

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Sorry mate...... I scream, you scream, we all scream..... but it didn't make it home :P

Yes, I have used the focus motor on a few contraptions & it has served me very well :)

Col

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Hi Damon

I have an unusual species of Poinsettia growing in my yard, the 'flower head', the red leaves & centre is about 40mm or 1 1/2" in diameter. Normally they are about 4 or 5 inches in diameter.

I haven't done any UVIVF before, but have been setting up to do some, but I can't replicate what you are getting ??

I have got my lights Mercury HID & MTE UV301 LED to output light in the LW UVA. They don't put out the amount of light as your 4 x Blak-Ray's, but they are all below 400nm. I have the hot mirror in the camera & use a 390nm UV block filter to be sure.

I am seeing with my eyes a nice violet on the red leaves & nearly normal visible reflection of the flowers centre parts. If I look through the hot mirror I mostly see with my eye a normal visible image. I, nor the camera, see anything like your nice cyans - greens - creams ?

I am wondering if I am doing anything wrong, or if you are getting some UV into your images ?

I haven't setup enough to post any photos yet, but I will when I get things stable.

Col

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Hey Col.

Happy to hear you are investigating this fascinating plant and diving in UVIVFL. Awesome! It is so cool.

 

First I will tell what I have noticed with UVIVFL (I am a newbie amateur and flying by the seat of my pants, so there will be flaws in what I state). There are MUCH smarter people here regarding this. But again, this is what I have observed in real time:

 

--If you are not @365 nm in particular, then you may not see what I am seeing. I only say that because I have a UV flashlight that was supposed to be @365 and not cheap, but also does not reproduce what the Blak-Rays do--not even close, even with a Baader U over the front. If I shine said flashlight (with Baader U) on my Sphagnum moss--Nada. With the Blak-Rays--regular Pink Floyd concert going on. I swear there is some thing to that exact wavelength--or very close to it. I am also assuming my Blak-rays are 365nm--but there is reliable data to back that assumption up on the UVP site.

 

--Using the test Shane suggested, (http://www.ultravioletphotography.com/content/index.php/topic/1125-sand-fluorescing-red/)

My setup with the Canon MPE-65mm and 100mm macro--I am not getting any leakage to my sensor. So I doubt UV/IR contamination is causing it. I tried the 100mm macro recently and it is good to go.

 

--If you are not COMPLETELY blocking the visible/white light from that MTE, I fear some of the good stuff is being overpowered.

I tried looking at this plant and other things in total darkness with the Blak-Rays and then slowly introduced a regular LED light from the side and when it got close, I watched the colors begin to change in front of my eyes. It was kinda cool and told me that although the LED (visible) had to be fairly close to matter--it did make a difference. Duh, right--BUT--A distance away though--say a few feet away and not directly facing the plant--did not really matter so much--practically not at all. But your MTE/HID is blasting it directly head on...which is why I am wondering. What I am thinking is that if you are seeing what looks like visible, then you may have visible light hitting it.

 

--Have you tried to shine each light individually on the plant? So it's not a combination of light sources.

 

--There is the off chance you have a different species which may express different UV induced visible emissions.

 

--I think for now, we can rule out your camera/lens because your eyeballs are not seeing the colors either. Unless you have freaky eyes or something. Do you have freaky eyes?

 

I need to find something that is known to only fluoresce at 365nm. Let me think about this some more. Maybe poinsettia's :)

My gut is telling me visible contamination.

 

-D

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As promised, I will post the photos of my polished balls, then a photo of the Poinsettia I have taken in UVIVF.

First, I need to apologise to Damon for my questioning his methodology, but there maybe something to learn here too.

 

I must mention something about the setup & camera.

The lamp, is a MTE 301 UV 365nm LED lamp, for the polished balls reflection shots I have placed in order, first a UG11 filter, second a Baader U2 filter & third no filter in front of the lamp.

The camera, is a Sigma DP2 APS-C Foveon sensor compact, fixed lens (24mm, min focus 300mm) full spectrum converted camera. I have placed in front of the lens a GG420nm low high pass filter & the original Sigma IRC, to make it a Visible light camera.

The polished balls & Poinsetta flower were placed in the lamps beam & about 300mm in front of the cameras sensor. Just for scale, the holes in the vase are 1/2" or 12mm dia.

When this flower ages some more & the seed pod opens, I will photograph it again, then it will be in a similar state as Damon's original.

Cheers

Col

 

post-31-0-98531600-1418736909.jpg

SDIM6222-Polished Balls, UVIVF, MTE 365nm LED lamp with UG11 filter & IRC + GG420 filters on camera.

Sigma DP2, ISO 100, F14, 1 second.

 

post-31-0-42071800-1418736927.jpg

SDIM6223-Polished Balls, UVIVF, MTE 365nm LED lamp with Baader U2 filter & IRC + GG420 filters on camera.

Sigma DP2, ISO 100, F14, 1 second.

 

post-31-0-83995900-1418736948.jpg

SDIM6224-Polished Balls, UVIVF, MTE 365nm LED lamp without filter & IRC + GG420 filters on camera.

Sigma DP2, ISO 100, F14, 1 second.

 

post-31-0-27436000-1418736976.jpg

SDIM6229-Poinsettia flower, UVIVF, MTE 365nm LED with UG11 lamp & IRC + GG420 filters on camera.

Sigma DP2, ISO 100, F7.1, 10 seconds.

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Now you two are absolutely forcing me to go purchase a blooming holiday Poinsettia

in order to provide another test to see where this Poinsettia thing is going !!!

 

Let me make sure I have the summary of facts correct.

Listing Damon's gear VS Colin's gear:

  • Illumination: Blak-Ray B100AP with stock filter VS MTE 365 UV-LED with Baader-U filter
  • Lens: Canon EF100mm f/2.8 Macro USM with no filter VS Sigma 24mm with original Sigma internal filters (GG420/IR-Cut)
  • Camera: Canon 30D stock VS Sigma DP2 APS-C Foveon mod
  • Both fluor fotos made in darkness

Col, you didn't say how long your exposure was. And the file EXIF is stripped so I can't retrieve it. Although your background is reflective and easily showing the illumination, it can take sometimes several seconds to expose the subject fluorescence when shooting in the dark. Even with Damon's very strong Blak-rays, his exposures are 3 seconds.

 

Lacking polished balls meself, I think I'll use the back of a kitchen spoon for the IR test.

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Meanwhile here's your Botany Lesson for the Day. Courtesy of the very interesting Euphorbia Planetary Biodiversity Inventory.

(How did we ever learn in the past without the Internet??)

 

Poinsettias, like other Euphorbiceae, have both male and female flowers. These are not specifically E. pulcherrima diagrams, but they are close enough.

 

Female flowers. The unlabeled yellow structure is a nectar gland.

cyathiumFemale.jpg

 

Male flower

cyathiumMale.jpg

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Thanks Andrea & thanks for the botany lesson.

I have added the camera settings to each photo.

 

Just a correction on the lighting info for me, not......MTE 365 UV-LED with Baader-U filter..... but....MTE 365 UV-LED with UG11 filter.

The polished ball test, in my case was for, visible light leaks, the camera blocked IR.

Only with the UG11 was the MTE 365nm UV LED free from visible light, above 420nm.

 

Cheers

Col

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Hi everybody

I have finally got a photo to show what my crazy eyes can see of this Poinsettia when it is bathed in UVA light from a MTE 365nm LED with a UG11 filter added to be sure no visible light is leaking past 400nm. This is what my crazy poor old eyes see & my even more crazy Sigma camera that definitely don't like low light situations.

With the photos above, that I did yesterday, I had a white cardboard background that was reflecting a lot of fluorescent cyan around & possibly even reflecting off the cameras lens too. Anyway, today, I used a matt black cardboard & the scene was very different, no fluorescent cyan banging around the scene, instead a very dark Poinsettia, showing nearly a visible image with just bearly any fluorescense showing.

Cheers

Col

 

post-31-0-65093900-1418816646.jpg

SDIM6233-Poinsettia flower, UVIVF, MTE 365nm LED with UG11 lamp & IRC + GG420 filters on camera.

Sigma DP2, ISO 100, F8, 15 seconds.

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Col, thanks for the correction. I will edit my summary above.

 

Your set-up is much improved with the black back drop. Good idea.

 

And there indeed appears to be little to no fluorescence - except for the areas where flowers fell off exposing the latex area which fluoresces a bit. And, of course, the ubiquitous dust bits and fibers which fluoresce cyan/blue.

 

So, what do we have here with the new photos? I am baffled by the lack of chlorophyll fluor in your poinsettia leaves. I am postulating two possible explanations:

  • differences in poinsettia types or in ages accounts for differences in fluor ?
  • the MTE is closer to the 385nm violet/blue area and does not induce chloro fluor ?

Yesterday I bought a blooming red poinsettia - interestingly harder to find than I thought it would be - gazillions of poinsettias available, but few actually showing their strange little flowers. And of course none of them had any identifying tag as to species or varietal name. Not likely that the typical buyer of holiday plantery would care about such things.

 

I will set up my experiment with both the 365nm and 385nm Nichia UV-Leds and see what I get. It will take a couple of days to get the results posted because as noted in another post my MacPro with the photo apps is currently missing its power cord.

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Thanks very much Andrea, glad you found a flowering Poinsettia.

I'll play a bit more with my setup & try it with the Mercury HID lamp too.

Cheers

Col

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Hey Col.

That is an interesting setup.

Can you possibly get closer to the poinsettia? Many times, the farther you get the less pronounced this fluoro stuff becomes.

Do you have a close up lens? Did you ever get that Blak-Ray? I am guessing not yet.

With my close up photo, I was under 10" away from the flower.

 

-D

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Hey Col.

That is an interesting setup. Thanks Damon.

Can you possibly get closer to the poinsettia? I am at min focus at 12" / 300mm with this camera.

Many times, the farther you get the less pronounced this fluoro stuff becomes. OK.

Do you have a close up lens? Yes.

Did you ever get that Blak-Ray? I am guessing not yet. No, not yet.

With my close up photo, I was under 10" away from the flower. OK.

 

-D

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Thanks Damon, for suggerting to move the lamp closer.

I moved the lamp closer to the flower, 4" / 100mm away, just out of the frame.

Did it look any different, only a day older, BUT there was more light in the camera ;)

Perhaps a little increase in some fluorescence, that may be a result of the flower aging ??

Definitely more light for the camera to handle it better.... even if it wasn't noticeable to me.

Cheers

Col

 

post-31-0-74111100-1418904811.jpg

UVIVF MTE 365nm LED with UG11 closer to flower, 100mm & IRC + GG420 filters on camera.

Sigma DP2, ISO 100, F8, 15 seconds.

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