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St. John's Wort (Visible, UV, SWIR 1500-1600nm)

Infrared Multispectral SWIR
15 replies to this topic

#1 Andy Perrin

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Posted 13 August 2019 - 05:15

I tried a St. John's Wort. The UV was mostly for comparison to the SWIR, but it came out rather nicely. What a lovely flower this is in UV!

Visible
sunshine, Resolve 60mm quartz lens, F16, iso2500, 0.02", DB850 + S8612 1.75mm
Attached Image: _DSC3085 sunshine Resolve60mm F16 iso2500 0.02%22 vis UVP.jpg

UV
sunshine, Resolve 60mm quartz lens, F16, iso2500, 2", 330WB80 filter
Attached Image: _DSC3079 sunshine Resolve60mm F16 iso2500 2%22 UV UVP.jpg
Attached Image: _DSC3080 sunshine Resolve60mm F16 iso3200 2%22 UV UVP.jpg

SWIR 1500-1600nm
pano shot with 50mm Thorlabs SWIR-coated achromatic doublet, stopped down. The filter was a Thorlabs 1500nm long pass.
Camera was the TriWave, and currently I have no idea how to quantify the exposure settings.
Attached Image: St John's Wort SWIR pano 2.jpg

Edited by Andy Perrin, 13 August 2019 - 05:19.


#2 dabateman

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Posted 13 August 2019 - 12:27

Andy,
Is that the full image circle of the Resolve lens on your sensor?
I remember it larger, but maybe that was only for infinity focus, when the lens is fully retracted.

#3 UlfW

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Posted 13 August 2019 - 13:25

View PostAndy Perrin, on 13 August 2019 - 05:15, said:

I tried a St. John's Wort. The UV was mostly for comparison to the SWIR, but it came out rather nicely. What a lovely flower this is in UV!
Yes it is a lovely flower with many interesting details when you look closer.

This is how the flower can look with a UV-B-G stack, on the lens. This is the Steve-approved stack:
Attached Image: Screen Shot 2019-08-13 at 14.48.23.png
S8612, 2mm + UG5, 1.5mm

With the typical UV-B stack:
Attached Image: Screen Shot 2019-08-13 at 14.50.49.png
S8612, 2mm + BG3, 2mm

The visual result from stacks mixing UV with small amounts of parts of the visual spectrum varies much.
The light source's spectrum and type of flower makes a big difference in how dark or bright the green areas become.
I suspect that the Bayer response differs enough in different camera types to be important too.

I used two Godox flashes modified with quartz flash tubes.
Camera: Canon EOS 60D, full spectrum modified.
Lens: EL-NIKKOR 80/5.6, old metal type, at f/16.

Edited by UlfW, 13 August 2019 - 13:28.

Ulf Wilhelmson
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#4 Andy Perrin

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Posted 13 August 2019 - 14:39

View Postdabateman, on 13 August 2019 - 12:27, said:

Andy,
Is that the full image circle of the Resolve lens on your sensor?
I remember it larger, but maybe that was only for infinity focus, when the lens is fully retracted.
No, the border has been photoshopped. It DOES vignette like crazy on mine, though.

#5 Andy Perrin

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Posted 13 August 2019 - 14:48

View PostUlfW, on 13 August 2019 - 13:25, said:

I used two Godox flashes modified with quartz flash tubes.
Camera: Canon EOS 60D, full spectrum modified.
Lens: EL-NIKKOR 80/5.6, old metal type, at f/16.
I still don't have a working flash. Both of the ones I got from my sister were dead. The Resolve lens has really bad abberation near the edges for me, and I was getting much sharper results with the EL-Nikkor 80/5.6, but the colors seem nicer with quartz. (The colors above are unaltered aside from WB; when I use any other lens I usually have to increase saturation a little on the yellow-green end.)

Edited by Andy Perrin, 13 August 2019 - 14:49.


#6 UlfW

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Posted 13 August 2019 - 15:53

View PostAndy Perrin, on 13 August 2019 - 14:48, said:

I still don't have a working flash. Both of the ones I got from my sister were dead. The Resolve lens has really bad abberation near the edges for me, and I was getting much sharper results with the EL-Nikkor 80/5.6, but the colors seem nicer with quartz. (The colors above are unaltered aside from WB; when I use any other lens I usually have to increase saturation a little on the yellow-green end.)
Sorry to hear that both flashes were dead.
Both lens spectral reach and light source spectrum is important for the colours.

If you ever decide to go for a modern flash, or two, I would recommend the Godox AD200Pro with the bare bulb replaced by a quartz tube and in a reflector.
I think I regret buying the AD 600 and would like to replace that to have two AD200 instead.

I finally got my indoors photo space ready with the flashes etc.
I am stunned by the result and sharpness I get without any motion blur.
Usually I had to wait for a clear sunny day without any wind and make many alternative exposures to get something useful, not blurred.
Complete absence of wind for up to 20s is very rare here.

Edited by UlfW, 13 August 2019 - 15:59.

Ulf Wilhelmson
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#7 dabateman

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Posted 13 August 2019 - 20:48

View PostAndy Perrin, on 13 August 2019 - 14:39, said:


No, the border has been photoshopped. It DOES vignette like crazy on mine, though.

I figured you croped to a square. I really like the circle though. Photoscape X can do circle crops. I have to play with that.

Ulf,
Where did you get a quartz bulb for the Godox 200?

#8 UlfW

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Posted 14 August 2019 - 04:13

View Postdabateman, on 13 August 2019 - 20:48, said:

Ulf,
Where did you get a quartz bulb for the Godox 200?

https://www.ultravio...dpost__p__25662
https://www.xenonfla...l-lamp_121.html
https://www.xenonfla...l-lamp_122.html

Both are a bit long and you must be VERY carful when bending the threads as they can break in the joining hard soldered point to the interface metal pin through the quarts tube.
I broke mine but was able to re-connect using a short piece of solder-wick as conductor after cleaning the interface pin and using solder flux.
Ulf Wilhelmson
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#9 Andrea B.

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Posted 14 August 2019 - 14:48

Nice work, Andy.
The St. John's Wort is indeed interesting. Hypericum species often feature little black dots on the petals and white dots on the leaves. Some kind of plant glands, I think. Yours appears to have the dotted petal edges. So I'm curious about whether the dotted petal edges showed up in the SWIR photo? I can't quite tell from the photo given that it requires your pano-ing together several shots.

Also nice work, Ulf.
I typically shoot the UV+blue+green filter stacks only under sunlight because the results with UV-flash or UV-LED on those stacks can vary quite a bit. But that is only my effort to represent the elusive "bee vision" and certainly not a requirement. :lol:

Gentlemen, any time you would like to add your photos to the botanical section, we would love to have the record. I can always help with formatting or the botanical details. It is OK to add a flower if only the genus is known. For example: Hypericum sp. [St. John's Wort] would be the title for Andy's flower.
Andrea G. Blum
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#10 Andy Perrin

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Posted 14 August 2019 - 15:16

Andrea can this website do forms? If you made a form that had all the standard fields then it would make me a lot more likely to contribute to the formal sections. As it is, it seems like a ton of work just to get everything resized for the site and the exposure info written up, even informally. Maybe I’m just lazy!

I plan to revisit this flower sometime and I will take a closer look at the petal edges. I should get some longer focal length SWIR lenses.

Edited by Andy Perrin, 14 August 2019 - 15:18.


#11 Andrea B.

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Posted 14 August 2019 - 16:02

That's a good question, Andy. I don't know the answer, but I'll look into it.

I just copy and paste from a stored template.
Below there's some boilerplate for you. :cool:
You can copy/paste this stuff to a topic you create in References, Lists & Stickies
which should be entitled: My Template: Andy Perrin
or Andy P. or whatever identifies your version to you.


The topic title (external) and topic header (internal) must follow the attached format so that I can search the material to create an index. But the remaining parts of the entry can vary a bit. You can copy/paste your template into a new topic in the botanical section. The topic entry does not need to be finished all in one session. I often get an entry started and have to come back to it over a few sessions. (Sad to say, there are still some unfinished entries by both me and Birna. We are always busy and sometimes forget to finish an entry! We do have a list of those.)


Topic Title Template: Genus species [Common Name]

Perrin, A. (2019) taxonName Author (familyName) commonName. Flowers photographed in [LIST] light.
LINK-TO-TOPIC

Location
Date
Wildflower
Wildflower in botanical garden/in home garden
Cultivar in botanical garden/in home garden/from florist/from grocery store

Botanical Synonyms:

Other Common Names:

Comment:
What is interesting or surprising about this flower? ....and its UV/IR properties? Where did you find it?

Reference:
Reference templates for website and field guide.
1. Wikipedia (Date_of_Accession) Title_of_Wikipedia_Entry_with_Link. Wikimedia Foundation, San Francisco, CA.
2. New England Wild Flower Society (Date_of_Accession) Taxon_Name_with_Link. Commonname.
3. Author (Date) Title_of_Field_Guide. Flower_Name, page xxx. Publisher.

Equipment [CAMERA + LENS]

Visible Light [f/xxx for 1/xxx" @ ISO-XXX with CutFilter in Sunlight/with XyzFlash]

Ultraviolet Light [f/xxx for 1/xxx" @ ISO-XXX with UvPassFilter in Sunlight/with XyzFlash/with XyzUvLed]

UV-Induced Visible Fluorescence [f/xxx for 1/xxx" @ ISO-xxx. Lens: FilterXyz. Light: FilterAbc. Photographed in Darkness/AmbientLight.]


If a flower has already been added to the botanical section, then the title for an additional entry becomes something like the following. You have some choice in the wording.

Topic Title Template: Genus species [Common Name]: Another Example

And the topic header should be similar.

Perrin, A. (2019) Another Example of taxonName Author (familyName) commonName. Flowers photographed in [LIST] light.
LINK-TO-TOPIC

The topic should include a reference to the original version of the posted flower. Other references may also be included.

Reference:
1. Rørslett, B. (DatePosted) Genus species [Common Name] with underlying link copied from that topic's header.
Andrea G. Blum
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#12 UlfW

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Posted 15 August 2019 - 05:22

View PostAndrea B., on 14 August 2019 - 14:48, said:

Nice work, Andy.
The St. John's Wort is indeed interesting. Hypericum species often feature little black dots on the petals and white dots on the leaves. Some kind of plant glands, I think. Yours appears to have the dotted petal edges. So I'm curious about whether the dotted petal edges showed up in the SWIR photo? I can't quite tell from the photo given that it requires your pano-ing together several shots.

Also nice work, Ulf.
I typically shoot the UV+blue+green filter stacks only under sunlight because the results with UV-flash or UV-LED on those stacks can vary quite a bit. But that is only my effort to represent the elusive "bee vision" and certainly not a requirement. :lol:

Gentlemen, any time you would like to add your photos to the botanical section, we would love to have the record. I can always help with formatting or the botanical details. It is OK to add a flower if only the genus is known. For example: Hypericum sp. [St. John's Wort] would be the title for Andy's flower.

Thank you Andrea.
My flowers have those black dots on both petals and anthers. They look like small droplets of tar.
The tips of the stigmas are red.
Attached Image: Screen Shot 2019-08-15 at 07.20.39.png

It appears like "bee vision"-images are very sensitive to the light quality.
I think that the characteristics of sunlight can change over the time of day and year and I want something more stable.
That is one reason for me using a flash setup.
I also think that the different bayer responses in different cameras can be important for this.

My main interest in UV photography is to see how very differently flowers looks and why, with different filter configurations.
At most I run through almost twenty different filters with each specimen.
I hope to add some of them to the botanical section in the future too and I'm looking forward to pointers about the errors I'll make. :smile:

The new indoors UV-photo setup with flashes is a way to restart that interest.
A few months ago I lost much interest in doing this, due to that I was told that so much was wrong, when I gave my first impression about the UG2A, 1mm + S8612, 2mm-stack.

I got a lot of new inspiration again now as things worked quite well with the indoors setup.
It is a pity that the flowering season is almost over now.

To make a correct identification of plants there are some important features to look for.
Can they be listed or are they always different, depending on species?
A short list would be useful.

Edited by UlfW, 15 August 2019 - 05:24.

Ulf Wilhelmson
Curious and trying to see the invisible.

#13 UlfW

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Posted 15 August 2019 - 06:25

I'm pretty sure my specimen is a Hypericum perforatum from sepal- and stem-shape

I cannot find how to see what sub-variant it is.
  • Hypericum perforatum angustifolium
  • Hypericum perforatum chinense
  • Hypericum perforatum latifolium
  • Hypericum perforatum perforatum
  • Hypericum perforatum songaricum
  • Hypericum perforatum veronense

Edited by UlfW, 15 August 2019 - 06:26.

Ulf Wilhelmson
Curious and trying to see the invisible.

#14 Andrea B.

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Posted 15 August 2019 - 14:22

I hope to add some of them to the botanical section in the future too....

Ulf, you can also copy the template I provided for Andy and store your version in the references section for copy/paste to a new topic in the botanical section. :smile:

I am thinking over what advice I would offer to someone who wishes to identify flowers. I think I will write it up as a separate topic.
Andrea G. Blum
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#15 UlfW

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Posted 15 August 2019 - 15:02

View PostAndrea B., on 15 August 2019 - 14:22, said:

I am thinking over what advice I would offer to someone who wishes to identify flowers. I think I will write it up as a separate topic.
That would be very useful, even if some identification tell tales are more species-unique, there might be some general things one can snap with the mobile-camera when on site.

Another thing I have been missing in images for identification is some size reference for the flowers.
At least I tend to fill the image as much as possible with the subject.
Sunflowers, Rudbeckias and Forget-Me-Not, are a bit different in size.
Maybe some kind of ruler or scale would be a good idea.

Edited by UlfW, 15 August 2019 - 15:02.

Ulf Wilhelmson
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#16 Andrea B.

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Posted 15 August 2019 - 16:12

Ulf, I'm not sure I have time to completely write up a good topic. So let me offer some pointers here. I will try to return to this after we have completed our move to Santa Fe to see if there are any other suggestions which I can make.

Photographs for identification purposes.
These do not have to be formal. Sometimes I simply use a point-and-shoot with macro properties like my old Coolpix A. You might not need to make every suggested photograph. For unknown flowers which cannot be harvested to take home (such as those which grow in a national park), make as many ID photos as you can. If you can cut the flower and ID it later at home, then you need to make only enough photos to support key parts of the identification to offer along with your formal portraits of the flower when posted online.
  • top and bottom of the flower.
    Top photo should show reproductive parts.
    Bottom (abaxial) photo should show sepals/receptacle.
  • side view of the flower
  • entire plant to show its growth habit and general relationship to its surroundings.
  • stem leaf both top and bottom to show its structure, edges, veins and hairs (if any).
  • basal leaf, if any, especially if different from stem leaves.
  • the way a leaf is attached to the stem.
  • stem near the flower and also somewhere in the middle.
  • any seed pods, seeds or seed fluff.
  • anything unusual or noteworthy (example: tiny stipitate glands)
  • Include a ruler or make size notes.
.
Identification resources
Narrow down as much as possible the resources you consult. For example, the official US flora is 20 volumes and still growing. So I look for resources which are specific to a US region, US state or county within a state (i.e. smaller US geopolitical regions).
  • Field guide (printed or online) for your region (town, county, province, state?) or country.
    Field guides are descriptive at a higher level than botanical keys.
  • Botanical key (printed or online) for your region or country.
    Botanical keys are very technical and require an at-hand glossary of terms.
  • List of wildflowers (printed or online) for your region or country.
    Simple lists containing both common name and scientific genus/species are useful for quick reference.
General Botanical References
There are literally thousands of botany books and formal textbooks. But there are two inexpensive botanical references which I have found both delightful and quite useful. Perhaps you might also enjoy them.
  • Botany in a Day by Thomas J. Elpel http://www.wildflowe...ay_Download.htm This is a wonderful book which describes the plant familes (such as Asteraceae = sunflower family or Fabaceae = pea family). I think that Mr. Elpel now offers most of the info online if you don't want a printed book. But the book is very cool.
  • Plant Identification Terminology, 2nd Edition by Harris & Harris
    It is the illustrations in this book which make it invaluable when you are trudging through a formal botanical key wondering what in the world means "tomentose". The book is out-of-print but still available.



Ulf, in the case of your Hypericum above, we would generally recommend stopping at a genus/species identification. Identification of a sub-species or a variety is highly dependent on the geographic location in which a particular plant is found and a difference of only a few miles/kilometers can alter what sub-species (if any) are found in a region.
Often, identification beyond genus/species requires trips to herbariums to compare to actual specimens or requires DNA analysis or microscopic analysis. Professional botanists sometimes get into wild discussions and fights over whether plant is a variety or a sub-species or what particular variety or sub-species a given specimen actually is. (Sometimes that happens when attempting to determine species also.)
Andrea G. Blum
Often found hanging out with flowers & bees.