Lechenaultia macrantha

[LookCloser]

I was experimenting with my new full-spectrum camera over the last few and came across a fantastic UV signature on one of our Western Australian endemic plants. Lechenaultia macrantha. The wreath flower. I hope that I have imaged it correctly because I am very interested to see if anyone has seen something similar.

 

Olympus em5 full-spectrum converted. Enna Munchen 35mm Lithagon. Kolari UV band pass (Image1) and Kolari visible bandpass. Image 3 is with my unmodified camera with flash

 

 

 

 

[microbat52]

Ooooh so cool!

[Andrea B.]

Wow! That is a beautiful flower with a wonderful UV-signature. Did you look in our botanical section for it. I'll check and get back to you here.

[Andy Perrin]

It's a gorgeous flower in UV. I do wonder about the white balance on that photo, and if any IR is getting through (given the filter is the Kolari which sometimes has problems with that). How are you doing the white balance?

[Andrea B.]

Goodenia Link: https://www.ultravio...8-goodeniaceae/

 

The majority of our Austrialian examples were photographed by our member Dave Oldfield. So do look in the botanical section for examples of his work.

 

The currently posted photos for the Goodenia family do not include Lechenaultia macrantha. I would LOVE to have this gorgeous flower with the very cool UV-signature added to the Goodenia section. But first a couple of comments.

• Your UV photographs shows the UV-signature, no doubt. But to post it in the botanical section we need a standardized white balance.
  

• To properly process your visible photo from the converted Oly, you also need to correct the white balance. The UV/IR-Cut filters used with a conversion do not do this automatically.
  

Please look at this Sticky for information about standardized white balance:

Sticky :: White Balance in UV/IR Photography

 

After you read up on that, you can experiment with corrections for your photos.

Ask any questions, we are happy to try to answer them.

[Stefano]

So this flower has a sort of "negative" pattern, bright in the middle and dark outside. That's very unusual, flowers (to my knowledge) are either darker inside or have a uniform color in UV. That's very cool.

[Doug A]

I was experimenting with my new full-spectrum camera over the last few and came across a fantastic UV signature on one of our Western Australian endemic plants. Lechenaultia macrantha. The wreath flower. I hope that I have imaged it correctly because I am very interested to see if anyone has seen something similar.

 

Olympus em5 full-spectrum converted. Enna Munchen 35mm Lithagon. Kolari UV band pass (Image1) and Kolari visible bandpass. Image 3 is with my unmodified camera with flash

 

 

 

 

 

Great images! Wish the plants were available in the US.

 

Thanks for sharing,

Doug A

[colinbm]

Beaut flower

[LookCloser]

Thanks everyone, it is indeed a beautiful flower.

Andrea, I'd be surprised if this species was in your botanicals section. I have browsed through David Oldfield's gallery and the Australian botanicals index. Most of the species are east coast. Where I am on the western side of the continent we have a hugely disproportionate number of endemic species, L. macrantha being one of them. This is why I was quite excited to get out and image some of these species. It is fertile new ground.

 

I undoubtely need to work on my white balance and will read the article at the end of your link. I will attempt to correct the white balance on these images, however it is impractical to reshoot them. It is a 1000km / 600mi round trip to photograph them again so if correction fails then I will have to wait until next year. There are plenty more subjects in the meantime.

 

I also imaged another congeneric species (L. biloba) endemic to the region, which shows a more typical black centre UV pattern.

[DaveO]

Hello LookCloser,

 

You are in the box seat for Western Australian wildflowers. We only visited your beautiful part of the world on our Long Service trip way back in 1979 when I had never heard of digital UV images.

 

I happily vacate the field for you - go for it!

 

Best wishes,

 

Dave

[Andrea B.]

LookCloser -- I would be happy to convert your raw UV file if you can put it in a dropbox somewhere.

But no problem if you don't want to do that.

 

*****

 

Dave, I won't hear of you vacating the field! Australia has a gazillion unphotographed flowers. The more UV photographers, the merrier !!

 

*****

[DaveO]

Here, hot off the press, is the latest list of rare and endangered plants for my neck of the woods

 

A lot more exposures to be made

 

rare-threatened-and-endangered-plants-of-the-castlemaine-district-cfnc-aug-21.pdf

 

Dave

[LookCloser]

Thanks Andrea. I'm more than happy to have you process the RAW, I'll pop it in a dropbox folder. If you send me an email address via PM I'll add you to the box.

I'm looking forward to seeing what you produce.

 

I have a PTFE plate in the mail so that should improve my white balance somewhat

 

Dave, no need to vacate the field! There are far more plants here in Australia than you and I could ever get through.

 

 

 

Mat

[Andrea B.]

LookCloser (Mat) has generously shared some of his Australian UV-flower files with me so that I could have a chance to work with some raw ORF files from the Olympus EM-5. I've worked with many conversions but not yet with an Olympus full-spectrum which several members have made very good use of. (Pedro, Dabateman come to mind.) So this was fun for me.

 

I'm going to post a few results below.

 

Thank You, Mat !!

---

 

 

GEAR: Olympus EM-5 Full-spectrum conversion + Enna Lithagon 35/? + KolariU + Sunlight

 

I found the raw ORF files to be robust and easy to work with in Photo Ninja when making the usual white balance and black/white point edits along with the occasional use of the illumination slider to bring up an exposure.

 

Please note that the results I'm posting have only global edits. Time constraints always get in my way, so, for example, I couldn't brush in detail/sharpening enhancements only over the flowers.

 

I *completely* understand about capturing those motion-blurred flowers when one is outdoors battling the breezes trying to learn for the first time how to wrangle that slow-exposure UV. The hardest thing to photograph in UV is flowers in the field, methinks. Landscapes generally hold still. Little flowers do not.

 

Everybody knows how much I like to see the actual raw colors which a particular lens + camera + filter combo can capture. So I did a bit of raw color analysis too.

 

 

WHITE BALANCE

I used two methods which are applicable when there is not a photograph of a UV-stable white standard.

 

First, I white balanced the files in Photo Ninja by dragging the white balance dropper over areas which are generally UV-neutral. Sometimes these are backgrounds, sometimes sticks or stems, or the ground, or rocks. Or sometimes you look at the raw colors and drag the dropper over the pinks/magentas. When performing this kind of trial-and-error white balancing your goal is to make those blues/yellows/greys/whites/blacks appear and to make all hints of pink/magenta/red/rose disappear.

 

Second, as a confirmation that my Photo Ninja effort was basically OK, I used Raw Digger's RGB Render. This is a very conservative white balance based on the white point of the camera and analysis of the image data.

 

The two methods produced the same WB. Of course the files from Raw Digger are a bit duller and less saturated than what we get from the usual conversion results in an app like Photo Ninja.

 

Schoenia cassiniana

Pink Clusters

 

 

Rays (petals) are false blue and disk flowers are false-yellow. Very interesting.

 

 

 

 

 

Podolepsis aristata

Copper-wire Daisy

 

 

Another one of those fascinating flowers which shows both false-blue and false-yellow.

 

 

[Andrea B.]

Lawrencella davenportii

Sticky Everlasting

 

 

Now I'm beginning to think that all Australian Asteraceae have both false-blue and false-yellow !!

 

 

[Andrea B.]

Leuchenaultia macrantha

Sticky Everlasting

 

 

First the visible reference photo.The wreath flower is a visible white-to-cream hue with soft markings of pink -- like a pink blush -- on the upper petal. This is so beautiful.

 

 

White flowers can be UV-absorbing or UV-reflective. The petals of these Wreath Flowers are moderately UV-absorbing with a striking UV-reflective stripe on the lower three petals. There is a UV-bright ring on the protruding "nose" and two UV-bright stripes on the edges of the upper petal.

 

 

 

The raw colors here happen to contain an almost textbook example of red, blue and magenta.

Red, leftmost middle Blue on bottom. Magenta, two on bottom

The topmost circle is purple. The rightmost circle I would call "cerise".

[Andrea B.]

Out of my own curiosity -- given the raw colors in the Lechenaultia file -- I made a little experiment about white balance. OK to ignore if you are not interested !!

 

White balance on a raw Blue area.

This gives an overall yellow cast. Look at the ground which should be a grey hue under the kind of standardized WB we make using UV-stable white standards.

 

 

White balance on the a raw Magenta area.

This produces a UV-neutral ground, but there is still some yellow cast elsewhere.

 

 

White balance on raw Red gives an overall blue cast.

Again the ground is not UV neutral. But this looks a bit closer to the results I got above with RGB Render and also by "clicking around" with PhotoNinja's white dropper tool.

 

 

---

 

 

Thank you again, LookCloser, for this opportunity to explore ORF files and their raw colors. I think you will make some very cool reflected UV photographs with this gear. And I am definitely looking forward to seeing some of your UV floral signature captures arrive in our botanical section when you get the time.

 

---

 

I made an edit to change the order of the 3 photos here and rewrote the captions for clarity.

[Andy Perrin]

Andrea, do you think the odd initial coloring is just a function of the colors that stack gives, plus the white balance being not-quite-neutral in the original?

[Andrea B.]

I am thinking your are referring to the very first photo of the Wreath Flower (Lechenaultia macrantha) in LookCloser's Post #1? If not, then please ask me again.

 

The Wreath Flower has a dark yellow false color for the petals and a light blue ("lavender blue") for the petal stripes after application of white balance. The colors in the first photo in Post #1 are slightly off with an overall yellow tint to both the petals (OK) and the stripes/ground (not OK). I don't know what white balance LookCloser was using for that because I don't have an ORF app.

 

If you bring up the Digital Color Meter from Utilities on your MacBook, you can quickly check out the colors on the first photo in Post #1 and in the Photo Ninja and RGB renditions in Post #16.

 

The first photo (Post #1) almost looks like the petals are dark lime green, but it's not. It's dark yellow. In my two renditions the petals almost look dark brown, but it's really a darker dark yellow.

 

Dark yellow is R=G with a large dose of B such that B

The blue stripes are R=G with a large dose of B such that B>R and R,G are >100.

 

The RGB Render version (Post #16) is probably too dark. A hazard when working with the raw data version of a file is that it is difficult to know what kind of tonality adjustments to apply to the rather dull exported RGB Render or Raw Composite.

 

The original ORF is a bit overexposed. I looked at the raw histogram in Raw Digger and all three channels had hit the wall. So the first photo (Pot #1), is a tiny bit too bright.

 

The Photo Ninja version is probably closest to the false color reality we're aiming for in a standardized version. (Such a turn of phrase there --- "false color reality". La !!)

 

.....once again delivering more than you ever wanted to know.....

[LookCloser]

Wow, thanks for all of your processing Andrea, you've done a great job.

That wreath flower has a super pattern, I'm so pleased that I just happened to think to image it in UV!

 

I will keep an eye out for more native Asteraceae to image and see if I can find the false-blues and false-yellows on others.

 

I think I'll have to read through your posts a couple of times to get a good handle on the colour science.

 

If you'd like to make your information complete, the lens I used is the Enna München Lithagon 35mm f3.5

 

 

In the meantime I've had a go with another image I took today just to prove to myself I am (hopefully) making some progress and that I can get some UV images that are sharper and closer to the desired focus depth/plane.

 

I used your guidelines for the processing in this case:

When performing this kind of trial-and-error white balancing your goal is to make those blues/yellows/greys/whites/blacks appear and to make all hints of pink/magenta/red/rose disappear.

 

This is a local naturalised weed Pelargonium capitatum. I didn't make the visible light image this time as I was just playing with camera settings but the flower shows such a nice pattern I think I'll go back and make a matching pair.

 

[Andrea B.]

That's a cool flower with those UV-dark "ears". Australia has some terrific flowers, for sure!

 

To hit the correct standardized white balance, you will probably want to get a piece of PTFE. You can make an in-camera WB setting from it. But then also make a raw photo of it for use in your chosen raw converter. Cameras don't always measure WB accurately with dark UV or IR filters, so the in-camera WB can be "refined" in the converter using the PTFE photo. The converter WB setting can be saved as a preset for use on other UV photos.

[[if this information is a repeat for you, please excuse me. I don't always know who knows what.]]

Reference Link: Sticky :: White Balance in UV/IR Photography

[LookCloser]

Thanks Andrea,

 

I have a couple of PTFE pieces coming in the mail so hopefully that will standardise my white balances.

 

The Perlagonium is unfortunately an invasive weed here but so long as it is around I may as well make the most of it.

I went back today and took a UV/Vis pair for comparison.

It's interesting that when you consider the whole inflorescence it makes a lot more sense. From the top the lower petals form the outer ring of a bulls eye.

 

Perlagonium capitatum

Olympus em5mk1

Enna Munchen Lithagon 35mm / f3.5

KolariU

Daylight.

Each image is a focal stack of 2 exposures

 

 

 

[colinbm]

Dazzling

[dabateman]

Excellent images.

Its great to see some different types of flowers.

I haven't had much at all in the yard this year.

[Stefano]

So interesting that the petals have two colors in UV while they are all pink in visible light.