Coreopsis, Echinacea, Zinnia: Small Garden Bouquet

[Andrea B.]

Blum, A.G. (2021) A Small Garden Bouquet of Coreopsis 'UpTick Gold & Bronze', Echinacea 'Kismet Raspberry' and Zinnia grandiflora Nutt. (Asteraceae) Tickseed, Coneflower, Prairie Zinnia. Flowers photographed in ultraviolet, infrared and visible light. https://www.ultravio...garden-bouquet/

 

 

La Secuela, Eldorado at Santa Fe, Santa Fe, New Mexico, USA

8 August 2021

Two cultivars and one wildflower from home garden

 

Comment: This colourful little bouquet becomes a more subdued black in UV and a rather plain white in IR. The rays of the raspberry Coneflower are quite velvety looking in both UV and IR. I had thought that the dark visible bulls-eye of the Coreopsis would carry over to the UV view, but it is very much less obvious there.

 

Reference:

1. SEINet Arizona-New Mexico Chapter (acc 08 August 2021) Zinnia grandiflora.

This is a southwestern biodiversity organization making use of the Symbiota portal software.

 

 

Camera & Lens: Nikon D610 Conversion + UV-Nikkor 105/4.5

 

Note: An earlier comment about exposure times has been removed because I based it on a typo I made. (Don't go to the bank on bad data, right???)

In general, recent exposure times for indoor photos made under skylights have been slightly slower due to smoke and haze in the air over New Mexico from the wildfires over in Arizona and California.

OK, that is accurate now. Thank you for your patience, readers of UVP, while I got this corrected.

 

 

Visible Light [f/16 for 1/3" @ ISO-200 under Ambient Skylight with Baader UVIR-Block Filter]

 

 

Ultraviolet Light [f/11 for 15" @ ISO-400 with SB-140 UV-Flash and BaaderU UV-Pass Filter]

Two flashes were fired in the 15" interval.

 

 

Infrared Light [f/11 for 1/1.3" @ ISO-200 under Ambient Skylight with B+W 092 IR-Pass Filter]

 

 

UV+Blue+Green [f/8 for 15" @ ISO-800 under Ambient Skylight with UG5(1.5mm) + S8612(1.75mm)]

[Stefano]

Nice blue vase in IR.

 

I notice that your IR exposure is significantly longer than your visible exposure, often they are comparable (I get about double the exposure time in IR). Is it the smoke?

[Andrea B.]

I don't think I have the exposure time right for that photo. :grin: Let me go see.

 

Later: That should be 1/13". That should 1/1.3".

Thanks for catching that.

 

Later: It was the visible photo which I thought was a bit slow.

Usually I can get a much faster time under the skylight on a sunny day.

 

Later: Now I think I should probably remove ALL comments about exposure times under skylights. I just again misread some exposure times for recent photos. Groan. I have errored myself into a rabbit hole for sure!!

:wacko:

Oh well. This stuff happens.

[dabateman]

Nice flower set.

I like to have a composition book with me when I photograph. So I can write down the exposure, filter and photo file number. I will akso add the date and camera being used. Then at the end I will photograph that page of notes so I have it at the end of the series. It keeps keeping track of what I did better.

 

I see you used the D610 for this and not the S1R. Is the S1R already not your favorite child?

[GaryR]

Beautiful compositions !

[colinbm]

Lovely examples Andrea & the glass jar is something else.

[Andrea B.]

Thanks all for stopping by!

 

These simple little bouquets in a jar can be fun to UV/IR photograph even when you are not usually a flower photographer.

 

Dave, I haven't totally figured out how best to white balance the S1R photos. The SilkyPix converter for the S1R does not seem to handle false-color white balance well. And Photo Ninja does not yet cover the S1R.

[dabateman]

Thanks all for stopping by!

 

These simple little bouquets in a jar can be fun to UV/IR photograph even when you are not usually a flower photographer.

 

Dave, I haven't totally figured out how best to white balance the S1R photos. The SilkyPix converter for the S1R does not seem to handle false-color white balance well. And Photo Ninja does not yet cover the S1R.

 

Thats critical to know. Did you try using Adobe Free DNG converter and open the DNG?

 

Photo ninja handles the DNG I write out from my Raspberry pi with the various HQ cameras using pyDNG, now called PiDNG.

 

[Andrea B.]

Have not tried that yet but thanks for the reminder! I'll get that onto the new laptop.

 

I was having some WB success with Dark Table, and I reread the manual (rather sketchy) for Really Raw Processor and got some good results there for WB of S1R files.

 

I don't think all changes must be made on the raw file. So if I can get a good WB and save the file as a TIF, then I can take that to Photo Ninja (or elsewhere) to finish.

[microbat52]

Niiiiiiice! I really like the violets and blues you got in the UV and IR.

[Andrea B.]

Thank you. "-)

 

I love those false blues too.

[photoni]

Thank you. "-) I love those false blues too.

 

 

A beautiful composition and beautiful interpretations

 

Andrea, Please...

explain two things to me.

I don't have the "Baader UVIR-Block Filter"

what do you think of the BG39? looks pretty good to me.

I was recommended the BG18, (it arrived recently, and it looks very similar to me) is it a fairer choice?

 

Can your fourth photo be understood as the beeVision ?

UV> Blue

Blue> Green

Green> Red

(red discarded from normal sight)

 

I did some tests, and three actions with photoshop, see this

Thank you

Toni

 

 

P.S. I wanted to post on UVP, I don't know where :)

[Andrea B.]

The 4th photo can be interpreted as a simplified, somewhat inaccurate emulation of the very complex Bee Vision. But I must add this: bees do not form images like we humans do. Thus the 4th photo shows only the colors which bees can detect and not how the bee actually "sees" the flowers. We still enjoy this kind of photo making with those filters which pass UV + blue + green even though it is an imperfect representation of actual bee vision.

 

Bees do not have a visual receptor which fires when the bee sees a red flower, but the bee knows the red flower is there. Bees make use of blue content, green edge contrast, foreground against background and other simple visual cues to detect nectar bearing flowers.

 

The color assignments are more complex than what you have listed. I am not an expert on this, but here is what I have learned over the years. On the left is the reflected visible light of a flower or other subject together with the UV reflectivity, or not, of that subject. On the right is the presumed color which a bee might detect.

• white + UV absorbing --> cyan.
  
• white + UV reflecting --> UV-cyan, not visible to humans.
  

• red + UV absorbing --> probably best represented by a neutral grey.
  Many red flowers have a blue component, so some red flowers might weakly stimulate the bee's blue receptors.
  
• red + UV reflecting --> reflected UV, maybe UV-blue, neither is visible to humans.
  

• blue + UV absorbing --> blue.
  
• blue + UV reflecting --> UV-blue, not visible to humans.
  

• green + UV absorbing --> green.
  
• green + UV reflecting --> UV-green, not visible to humans.
  

• yellow + UV absorbing --> probably a weakly stimulated green.
  
• yellow + UV reflecting --> probably a weak UV-green, not visible to humans.
  

• cyan + UV absorbing --> cyan.
  
• cyan + UV reflecting --> UV-cyan, not visible to humans.
  

I have some links to my attempts to more fully represent bee vision.

Let me go find them.

 

LINKS

 

There are two charts in the following post which illustrate the difference between our UV+B+G photo emulations of bee vision and how the bee might actually detect a flower.

https://www.ultravio...dpost__p__21230

 

This topic contains a bouquet which I have rendered in bee colors using a multi-colored pattern to represent any bee color which involves reflected UV.

https://www.ultravio...__fromsearch__1

 

Another bee vision bouquet in this topic:

https://www.ultravioletphotography.com/content/index.php/topic/1531-discussion-ug5u-330-s8612-filter-stacks-part-2/page__hl__%2Bbee+%2Bvision__fromsearch__1

 

Other discussions of bee vision.

 

https://www.ultravio...dpost__p__21036

 

http://www.ultraviol...ting-bee-vision

 

http://www.ultraviol...ated-bee-vision

 

https://www.ultravio...__fromsearch__1

 

https://www.ultravio...__fromsearch__1

[Andrea B.]

Any of the IR blockers will work reasonably well if you take some care to photograph a white standard using that IR-blocker at the beginning of each photo session. Later in the converter you use the white balance tool on that photo and save the result as a preset which can be applied to any visible photos from that session. You need this photo of a white standard made with your IR-blocker because it is quite often the case that making an in-camera white balance measurement produces a slightly inaccurate result depending on the darkness and/or thickness of your IR-blocker.

 

For further accuracy, a photo should be made of a color checker card using the IR-blocker. Then a color profile for that IR-blocker can be created for even more accurate color.

 

UVP members knowledgeable about IR-blockers recommend Schott S8612 glass as the best IR-blocker.

 

In the next post, Andy reminds us that the recommended IR-blocker for Visible light use is BG 38.

[Andy Perrin]

UVP members knowledgeable about IR-blockers recommend Schott S8612 glass as the best IR-blocker.

Not for visible rendition, though. It is the best IR blocker for UV photos. For best visible light colors, Cadmium recommended BG38 2mm to me.

[Andrea B.]

oh....I thought s8612 was best for both cases. I'll go cross that out. Thx!! 5 points to ya !!

[Andy Perrin]

oh....I thought s8612 was best for both cases. I'll go cross that out. Thx!! 5 points to ya !!

It's useable but blocks too much red, and even PN struggles to adjust for it. Thanks for the house points!

[Cadmium]

Andrea, great pics.

 

Personally I use BG38 for my visual filter. BG40 would be my next best choice, and may be a better choice for some cameras.

There is also Baader UV/IR Cut, but for me it looks too red.

Yes, S8612 would be more blue that the rest, but I have seen it work best for some people's cameras.

With my camera, this is how I experience all the BG filters:

Bluer < S8612 and BG39 - BG40 - BG38 - Baader UV/IR Cut > Redder.

 

As far as UV+Blue+Green, AKA Bee Vision, it is just a mix of false color UV and Blue and Green.

So it has all the false colors of UVA + Visual blue and green, which is not a perfect mix.

[dabateman]

Yes getting visible back really is tricky depending on camera. For my old Olympus four thirds cameras and my Sigma SD14 the BW 486 dichoic filter is best.

For my newer m43rds Olympus cameras the BG38 or BG40 work best.

 

Lenses can also affect this, as some Sigma lenses cut off into the IR, and many lenses cut off the UV, as we know.

[Andrea B.]

There is also Baader UV/IR Cut, but for me it looks too red.

If a color profile is made for it, you will not see that.

[ulf]

I wonder how fast the reflectance changes for these test patches used for profiling.

 

For some flowers I have seen a very drastic colour change when switching between S8612, BG40 and BG38.

That indicates that the flower's reflectance changes quickly in the transition area of these filters.

 

I have a feeling that a colour profiling might not completely restore that.

Remember that colour profiling is aimed at improving the images from non converted cameras.

 

The dichroic filters like the Baader UV/IR Cut do not emulate a non converted camera well, as a converted camera lacks the BG-filter that normally is used to shape the light to the sensor.

[Andrea B.]

Well, we have to do something. And color correction profiles work better than anything else so far.

 

Color profiles are used for color standardization when photos are made under different lighting or at different times of the day, but the photos must show the same colors. I had to learn about color profiles for some magazine work I did a few years ago. (Travel photos in Italy.)

 

I've started adding a BG38 to the Baader UV/IR-Cut to give it rounder shoulders.