scales of the urania ripheus

[Adalbert]

Hello everybody,
This time the scales of the urania ripheus:

https://live.staticflickr.com/65535/495 ... b82f_o.jpg
( EOS M3 & EF 100L macro & Oly NeoSPlan 80x / 0.75)
BR, ADi

[Lou Jost]

We've all seen lots of pictures of this wonderful moth's scales, but these are outstanding. So sharp and well-lit, with the wild reflections very well controlled. How did you do the lighting?

[rjlittlefield]

Really nice! It's hard to illuminate things cleanly at such large NA. Have you shown us your lighting setup somewhere?

Edit: I see that Lou Jost and I have been noticing the same things!

--Rik

[Adalbert]

Hello Lou, hello Rik,

How did you do the lighting?

- light: 4 * YN660, 200mm, 1/128 power, 2S, between curtains controlled by my rail
- lens: https://www.photomacrography.net/forum/ ... t=neosplan
- tube lens: CANON EF 100L macro 2.8 USM / IS
- rail: https://www.photomacrography.net/forum/ ... 5&start=45
- rail & diffuser:


- subject


BR, ADi

[rjlittlefield]

So, four flashes diffused through plain white paper, with the subject mounted against a black cylinder background?

--Rik

[Adalbert]

Hello Rik,
Yes, two layers of the transparent tracing papier (distance between about 3mm).
BR, ADi

[Lou Jost]

Thnaks for sharing, really nice.

[Chris S.]

Adalbert, outstanding image! Very well done.

For clarity, let me suggest that Adalbert’s nicely diffuse lighting may not be the only reason that his wing scales lack the "wild reflections" seen in most wing-scale images of this moth. I think Adalbert’s lack of reflection may be largely due to his photographing a group of scales that are inherently less reflective than the scales commonly seen.

Another excellent, recent photograph of Sunset moth scales is Guppy’s Guppy’s Urania ripheus, 60X. A viewer clicking back and forth between these images may see, as I do, significant physical differences between the scales represented in each image.

In my experience, U. ripheaus' non-shiny scales are rather flat, while its shiny scales are sharply curved; the non-shiny scales tend to have zig-sag terminal edges, while on the shiny scales, terminal edges have either much less defined zig-zag, or display curviness. Lastly, the surface of the shiny scales seems covered with shiny strips that have irregular cracks running cross-wise or diagonally; the surface of the non-shiny scales shows much more regular, lattice-like structure.

I've photographed the shiny scales, dark black flat scales, and some green flat scales on moths of this species. (Perhaps more types of scales as well, but these are what come to mind.) My sense is that Adalbert's image should be respected as one of the first to show such color variety in a group of flat, non-shiny scales on the Sunset Moth. A very nice feat! But different from a feat of eliminating shine from shiny scales.

Am I mistaken?

--Chris S.

[Adalbert]

Hello Chris,

Actually I wanted to show the net-structure of the scales. I was not interested in the colors and reflections.
So, my intention was to find the scales without any grid-structure but I haven’t found any such scales up to now
Please take a look at the picture of Maikl:
https://www.photomacrography.net/forum/ ... n&start=45

Concerning your theory about the two kinds of the scales I would suggest that you take a look at my photo taken by Mitty 20x of the scales of the urania.
https://www.photomacrography.net/forum/ ... highlight=
So, you will find the different reflections on the right and left site.

BR, ADi

[rolsen]

This is one of the best scale images I have seen!

[Chris S.]

Actually I wanted to show the net-structure of the scales. I was not interested in the colors and reflections.
So, my intention was to find the scales without any grid-structure but I haven’t found any such scales up to now

Adalbert, in your use of the terms, is there a difference between "net-structure" and "grid structure"? To me, these terms mean the same thing.

To my eye, the scales you photographed do show the grid structure so common (universal?) to lepidoptera scales. Maikl's SEM image that you linked to shows this structure more clearly, of course, as SEM can.

Concerning your theory about the two kinds of the scales I would suggest that you take a look at my photo taken by Mitty 20x of the scales of the urania.
https://www.photomacrography.net/forum/ ... highlight=
So, you will find the different reflections on the right and left site.

In this image, we do see different amounts of reflection, and some of this is likely attributable to differing angles of illumination, which I think is your point. Surely this is a factor.

But I wouldn't describe my sense of there being at least two kinds of scales on the sunset moth as a theory. It's an observation. I may not properly understand what I'm observing, of course, but I'm seeing something.

One observation is that if I make a strew of sunset moth scales on a microscope slide, some scales will adhere very flatly, and others will bend almost 90 degrees, with one side of the resultant L-shape adhering to the slide, and the other side standing up in the air. The flat ones have been plucked from the darkest (almost black-hole-like) spots on the moth; the L-shaped ones have been plucked from the shiniest regions. I've made strews of other sunset moth scales; though I've examined them far less intently than the deep black or very shiny ones, I get the impression that there are a number of physically different scale types on this insect, or at least some continuum of difference between the two types I've looked more.

Consider images 3, 4, and 5 in a thread I posted about testing a lens. Image 3 is one of the flat, very black scales of a sunset moth. (I use it for testing high-NA lenses, because the spaces between the grids range in size around the optical limits of these objectives.) Here, the scale is backlit, so no color information is available. But having view this scale, and others like it, many times with front lighting, I can say that it stays black.

Image 5 is obviously not a strew, but scales still on a sunset moth wing in a more typical shot. These shiny scales are the sort that would stand up curled in a strew.

Cheers,

--Chris

[Adalbert]

Hello Chris,

In this image, we do see different amounts of reflection, and some of this is likely attributable to differing angles of illumination, which I think is your point. Surely this is a factor.

yes, the angle of the illumination makes the difference.
Your GIF : “Tested lens / My lens ½ micron ” shows perfectly the grid-structure.
I would like to stress that I’m not interested in the structural coloration of the urania but in the grid of its scales.
My theory is that the “standard” scales have the grid-structure and the fact if it is visible on the picture depends on the illumination.
BR, ADi

[Chris S.]

Adi,

I think you and I are in general agreement. My quibbles, if any, are in details.

yes, the angle of the illumination makes the difference.

I'd agree that the angle of illumination makes the difference in the particular photographs you've referenced, both of which seem to feature relatively non-curling scales. But I'd question if in broader contexts, angle of illumination only makes a difference--that there may be other factors coming to bear. Perhaps it's nothing more than some scales--the ones that seem most highly reflective--having more natural curvature, so that it's difficult to find an angle that isn't reflective for some portion of the scale.

I would like to stress that I’m not interested in the structural coloration of the urania but in the grid of its scales.
My theory is that the “standard” scales have the grid-structure and the fact if it is visible on the picture depends on the illumination.

I don't know which of the various scales on U. ripheus you're calling "standard." But if you mean the most highly reflective scales, I don't think you've included them in the images referenced in this thread. Rather, my sense is that you're photographing scales that are about midway between this moth's most reflective and least reflective scales.

Nonetheless, I'd bet your hypotheses are solid that all these scales have a grid-like structure, and that our ease of seeing these grids with light microscopy has a strong dependence on illumination. As you pointed out, SEM images seem to suggest this.

As an aside, I once shot thousands of frames of single scales of the highly curved, reflective type adhering to microscope slides. I don't recall any of these images showing a grid-like structure. But elucidating the grid wasn't my purpose; rather, I was trying to characterize the scales production of interference colors using light sources with narrow incident angles. What I ended up accomplishing was an interesting demonstration of utilized aperture effects. I repeated some of the shots with diffuse lighting; this eliminated the utilized angle effects, but did not show the grids.

Fun conversation, Adi. Thanks!

--Chris S.

[Macrero]

That's some great work! Very clean, detailed image with perfect lighting.

I am planning to shoot scales at high M this winter, I currently own two 20X objectives: Oly UMPlanFl 20/0.45 and Oly LMPlanFl 20/0.40. Also a Nikon 40/0.5 ELWD and 100X/0.75 SLWD.

Recently bought an Oly UMPlanFl 50/0.80. I opted for the BD version, given its cone-shaped front part. Most likely I would have to saw the front part of the housing just like you did with yours. Lighting with 1mm WD is tricky.

Btw, I don't currently own an Urania Ripheus, but I haven't seen that kind of scales. Can you show the part of the wing where those are located?

Best,

- Macrero

[Adalbert]

Hi Chris,
You’re welcome, the pleasure is mine :-)

But elucidating the grid wasn't my purpose; rather, I was trying to characterize the scales production of interference colors using light sources with narrow incident angles. What I ended up accomplishing was an interesting demonstration of utilized aperture effects. I repeated some of the shots with diffuse lighting; this eliminated the utilized angle effects, but did not show the grids.

I totally agree, you can see on the photographs only that what the photographer wanted to show :-)
BR, ADi