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Bidens sp(?) (vis, UV-A, SWIR 1500-1600nm)

Infrared SWIR Multispectral
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#1 Andy Perrin

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Posted 04 September 2019 - 18:01

Not sure what this is, but obviously a close relative of black-eyed Susans. This flower continued the trend where the disc flowers of aster family flowers are interesting in SWIR.

Visible
The colors are not quite true on this, because I did an autotone in PS, but they came out so nice that I kept it anyway. The yellow parts of the flower stayed yellow, though.
Attached Image: _DSC9625 vis small UVP.jpg

UV-A
This is HDR with 4 images. WB off PTFE, didn't monkey with the colors much beyond what the HDR did to it.
Attached Image: UV HDR resolve60mm NEX-7 denoise UVP.jpg

SWIR
A large panorama with 164 images.
Attached Image: SWIR pano smaller UVP.jpg

Edited by Andy Perrin, 05 September 2019 - 18:20.


#2 dabateman

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Posted 05 September 2019 - 02:02

An other interesting SWIR image. The details on the head are nice. You can see into the cone like structure. I was also expecting to see more of the damaged petal spots. However, not all of them translate over into the SWIR image. I can't immediately identify the flower in the top of the SWIR to the flowers in the visible. The 2 spots should be easy to pick up on a petal.

Is the top most SWIR flower the Right most flower in the visible image? It seems to be similar, just rotated, interesting that not all dark spots line up. The SWIR is really different.

Also the two dark spots in the visible center flower are white in the SWIR image, as the far left flower. Possibly pollen not petal damage.

Edited by dabateman, 05 September 2019 - 02:12.


#3 Andy Perrin

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Posted 05 September 2019 - 02:23

Quote

Is the top most SWIR flower the Right most flower in the visible image? It seems to be similar, just rotated, interesting that not all dark spots line up. The SWIR is really different.
Yes, that's correct. Also viewed from above rather than at an angle. I see the two dark spots in the visible, but they don't look parallel. Possibly one or both is an insect. Or it may be the angle.

#4 Andrea B.

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Posted 05 September 2019 - 15:44

This seems to be a Bidens species, q.v.
It is interesting that the deterioration at the distal end of the rays corresponds to the UV reflective tips. As those areas are probably dried out (as the flower ages), they also are distinctive in the SWIR version.

The SWIR is really a good one.

For many of the UV-signatures in Asteraceae we can very reasonably accept the postulate that the UV-absorbing (dark) areas protect the central reproductive parts from sun damage. In this Bidens, however, it is difficult not to think that those very bright tips aren't acting as some kind of signal to pollinators. :grin:
Andrea G. Blum
Often found hanging out with flowers & bees.

#5 Andy Perrin

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Posted 05 September 2019 - 18:13

It seems that I need around 100+ images minimum to make high quality SWIR photos. Oh well, I guess if that's what it takes!