Moth wing as a lens testing target, images added

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NikonUser
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Moth wing as a lens testing target, images added

Post by NikonUser »

In a recent post
http://www.photomacrography.net/forum/v ... hp?t=15882
Rik argued against the use of a moth wing "moth wings aren't very flat". True.
But there is a way around this problem. Simply stick a piece of Double-Coated Tape (Scotch (3M) #667C) used for mounting photographs onto a slide. Place a piece of wax paper, the type that sticky labels are attached to,
and flatten and squash the tape, use as much force as not to break the slide. Remove a moth wing from the body, place it on the tape and again, using wax paper, apply as much force as you can to flatten the wing.
No damage will occur.
The following is a full frame of such a wing with a 4x Nikon CF N Plan Achromat, NA 0.13. Distance between the sticky tape and the top of the wing is 200µ (stack of 11 images @ 20µ).
Image
NU12005
Last edited by NikonUser on Fri Feb 03, 2012 6:09 am, edited 1 time in total.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

rjlittlefield
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Post by rjlittlefield »

Clever!

As I understand this, the scales on the underside are attached to the wing well enough that by sticking the scales down, the membrane can be held flat.

It is an idea that had not occurred to me, and it addresses very well one of the three issues that I ran into.

--Rik

NikonUser
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Post by NikonUser »

Yes that would be my understanding.
An alternate would be to brush the scales off of the ventral surface, this would need to have the wing still attached to the moth and the wings spread in the standard manner. Then break off the wing and stick it down. Probably would not have to brush off all the scales.
When carefully handled, moths and moth wings are tough characters.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

Chris S.
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Post by Chris S. »

Thanks, NU. While scored sandpaper may be entering my set of test subjects, moth and butterfly wings are certainly not leaving it. This approach may make mine flatter.

--Chris

NikonUser
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Joined: Thu Sep 04, 2008 2:03 am
Location: southern New Brunswick, Canada

Post by NikonUser »

Thanks Chris.
Wing scales are made of chitin and are almost indestructible. So if you want a guaranteed flat field you could brush the scales off the wing and let them fall onto a sticky slide; difficult part would be to get a thin even layer of glue on the slide; the double-sided mounting tape may not be flat enough.
An alternative would be to let the scales fall onto a thin smear of mounting medium (e.g., Canada Balsam) and then cover with a coverslip.
If the wing is dry when you scrape off the scales there is no need to dehydrate the wing/scales (CB will not tolerate any water). Warming a wing to about 60C should remove all the moisture in the wing.
Alternatively, immerse a wing in absolute alcohol and brush off all the scales. The scales will eventually accumulate at the bottom of the dish. They can then be pipeted onto a slide, when all the alcohol has evaporated add a drop of mounting medium + coverglass.
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

ChrisR
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Post by ChrisR »

A Red Admiral wing, stuck with double sided tape to the flat top of a small goniometer, without any pre-prep, partly lifted off after a few weeks. So one of the refinements above would be worthwhile. I did use waxed paper to press it down.
It didn't occur to me that it might be interesting to see WHY it had unstuck!

I'm not sure if it's still around...

Chris S.
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Post by Chris S. »

NU, of my objectives, only a minority are fit for use with a coverglass. That fact interfered with temptations I've had to make a test slide with a combination of subjects--few moth/butterfly scales, pollen grains of various sorts, a few fungus spores, etc.

But I know very little about making microscope slides. Is there any good way to do that without a cover glass?

--Chris

Pau
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Post by Pau »

Chris, there is a techique called smear: you extend a liquid dragging it with the border of another slide over the slide. It is usual for make blood and bacteriolgical slides. To fix it you gently heat it over a gaz flamme, but I do not know if it would work with big subjects like moth scales.

Adhesive microscope slides do exist, I recall seing them in a visit to a research biotechnology lab. They are coated with an organic adhesive compound and the staff use them to facilitate the adhesion of microtome histological sections. I think it may be an expensive material and again I don't know if it may be useful for your purpose.
Pau

nucleobyte
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Post by nucleobyte »

If you have a can of spray-on photo adhesive like this around, it would probably be worth a try, and a lot cheaper than custom made adhesive slides. You could mask the slide a bit before giving it a shot of the spray.

NikonUser
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Location: southern New Brunswick, Canada

Post by NikonUser »

First let me thank everyone for their feedback.
I tried making a permanent mounts of scales on slides using Canada Balsam and coverslips. Both techniques worked,
(1) brushing dry scales off the wing and letting them fall onto a slide, and then adding a drop of CB and a coverslip;and
(2) brushing scales off under alcohol and letting the alcohol evaporate before adding the CB.
One problem (minor) was that many of the scales were pushed to the edge of the coverslip and beyond as the CB drop spread. Thus I ended
up with far fewer scales on the slide than I had hoped for; but still enough to to make the slide useful as a test for transmitted light.
Fixable by starting with more scales and a smaller drop of CB.

Chris R's wing became unstuck. I used 3M removable tape, possibly better to use their permanent double-sided tape.

Pau & nucleobyte: a glue smear may work, I recall using egg white as smear to make a sticky slide. I did make a sticky slide using using 3M Super 77 spray adhesive, it worked but gave a thicker and more uneven sticky surface than the double-sided tape.

Chris S: for reflective work there is no need for a microscope slide, in fact better not to use such a small glass surface - see below.

Latest configuration:
1) use a piece of flat stiff card, foam-core board seems ideal.
2) Attached a strip of 3M double-side tape across the center, use permanent stick tape.
3) Attach a white sticky label to the top surface of the double-sided tape, paper side down. The sticky surface of the labels I have is much smoother and more even than the sticky surface of double-sided tape.
4) Press detached wing onto label, press hard using wax paper. The flattest part of the wing will be at the apex where the wing veins are weakest. The least flat part of the wing will be near the wing base where the veins are much thicker and stronger. Use wing tip for testing. Top image.

5) An alternative to (4) is to press the upper surface of the wing onto the sticky label and then remove the wing membrane. This leaves most of the scales on the tape in one flat layer. Major problem is that the upper surfaces of the scales, with all the nice fine striations, are hidden below the bases of adjoining scales. But, isolated scales may be useful. Last 3 images.
Last image is full frame (23/6 x 15.8 mm) using Nikon 20 CF M Plan objective on bellows @ 20x.
Image
Image
Image
Image
NU12009
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.

Nikon camera, lenses and objectives
Olympus microscope and objectives

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