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Another "yellow flower"

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#1 Cadmium

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Posted 19 July 2020 - 04:48

Here is another yellow flower, I don't know the name, that is fine with me. I usually don't think of photographing this flower.
This flower glows wild and prolific in my yard this time of year. The bloom is tiny, about 12mm in diameter.
Here are visual and UV wide shots, and close up UV, UV+Blue/Green, UV+Blue+, and IR flower shot comparisons.
Wind was relentless, and I didn't get very good sharpness with the small bloom shots.

Visual wide area shot (Schott BG38 2mm).
Attached Image: small_yellow_flower_visual_1280.jpg

UV wide area shot (Hoya U-360 2mm + Schott S8612 2mm stack).
Attached Image: small_yellow_flower_UV_1280.jpg

Top row left: UV (Hoya U-360 2mm + Schott S8612 2mm stack).
Top row right: UV+Blue+Green, 'Bee Vision', 'BUG' (Schott UG5 1.5mm + Schott S8612 2mm stack).
Bottom row left: IR (Schott RG695 2mm).
Bottom row right: UV+Blue+ (Schott BG3 2mm + Schott S8612 2mm stack)
Attached Image: full_4_flower_text_1280.jpg

Edited by Cadmium, 19 July 2020 - 04:51.


#2 Andy Perrin

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Posted 19 July 2020 - 06:14

Interesting that the UV-Blue-Green photos are so different from one another. The IR is surprisingly pretty here.

#3 Bernard Foot

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Posted 19 July 2020 - 10:12

Fascinating filaments - they look like insect legs! As Andy says, the IR shot is better than most I have done, which just come out plain white. It inspires me to try photographing the business end of flowers in IR.

My bet (relying on my friend identify.plantnet.org) is on Hawk's-beard (Lapsana communis)

Edited by Bernard Foot, 19 July 2020 - 10:19.

Bernard Foot

#4 Cadmium

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Posted 19 July 2020 - 12:27

Andy, the BG3 + S8612 stack usually looks darker red/brown than in this example. My usual stack is BG3 1.5mm + S8612 1.5mm, rather than the 2mm + 2mm stack I used here,
so I don't know if that has to do with it, I tend to think it doesn't. The 1.5mm + 1.5mm stack has a little more green, up from 500nm cutoff to about 510nm.

Bernard, I think you nailed it, Hawk's-beard (Lapsana communis) sure does look like what this is to me.

Note the little pods in the visual shot (which I don't see included in the UV shot) which have little dots inside them, I think these are the seed pods remaining after the flower looses its petals,
you can also see some of the old discarded shriveled up petals laying on the leaves

Here is a comparison graph.
Attached Image: UG5_1p5mm_x_S8612_2mm_vs_BG3_2mm_x_S8612_2mm.jpg

BG3 1.5mm + S8612 1.5mm stack.
I don't think it makes much difference if you use S8612 1.5mm or 2mm thick for this stack. The BG3 thickness is what changes the 500/510nm cutoff.
It actually will make a difference in color with some details sometimes, but I don't think it changes the reds.
Attached Image: BG3_1p5mm_x_S8612_1p5mm_stack.jpg

Edited by Cadmium, 19 July 2020 - 12:33.


#5 nfoto

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Posted 19 July 2020 - 13:34

Bernard's ID is exactly what I would have suggested -- if he hadn't beat me to it :smile:

#6 UlfW

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Posted 19 July 2020 - 13:59

It seams not to be native in America:
http://linnaeus.nrm....sa/lapscomv.jpg
But still locally present.

Edited by UlfW, 19 July 2020 - 14:42.

Ulf Wilhelmson
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#7 Cadmium

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Posted 20 July 2020 - 06:06

Simulated UV film from channel mix of BUG 5 shot.
Attached Image: Bug5_channel_mix_UV_film.jpg

Edited by Cadmium, 20 July 2020 - 06:23.


#8 Andrea B.

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Posted 21 July 2020 - 17:42

Definitely a Lapsana communis. Very distinctive growth habit.

Cadmium, your work here should be in the botanical section as a formal entry. If you would like to do this, PM me and I'll give you the headers and other text to make an entry there. (Or you can DIY.)
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