dorsal view

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proullard
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dorsal view

Post by proullard »

I take images for the San Diego Natural History Museum entomology dept. on a volunteer basis, (but I don't get paid enough!).

I need someway to photograph an insects dorsal view with a Cognisys stacking system on a horizontal plane. That is the camera is mounted on the Cognisys horizontally so I need the insect with the dorsal or top facing the camera. All the insects are specimen's so they are pinned.
Previously I was using a system that was mounted vertically so there was no problem shooting from the top down.
Now that that has changed I need a way to mount the specimen. Any suggestions?
I could stick it in clay which would work I suppose.
I was having a problem with the lens barrel of my Canon 65mm MPE lens moving while hanging vertically. Yeah I know you can put blue tape on the lens but that is a pain. Thanks.

Len Willan
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Post by Len Willan »

Hello proullard,

This is the way that that I photograph Pinned Entomological Specimens Horozontal.

View topic - PHOTOGRAPHING PINNED INSECT SPECIMENS

https://www.photomacrography.net/forum/ ... highlight=

This is a very safe method, as opposed to any Vertical Set Up.
Regards,
Len

Chris S.
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Re: dorsal view

Post by Chris S. »

Proullard, welcome aboard! :D
proullard wrote: Previously I was using a system that was mounted vertically so there was no problem shooting from the top down.

(snip)

I was having a problem with the lens barrel of my Canon 65mm MPE lens moving while hanging vertically. Yeah I know you can put blue tape on the lens but that is a pain. Thanks.
If you're taking numerous dorsal shots of insects already pinned in horizontal mounts, it might be easier to fix lens creep in the vertical system than go horizontal and hassle with specimen placement and risk for each and every subject.

Rather than tape, I'm imagining an arm (perhaps an Arca-style rail) mounted to the camera base, running parallel to the lens axis, with a moveable brake that lets you lock the lens once you've set magnification. It could be quick to adjust, should easily quash lens droop from gravity, and shouldn't be difficult to assemble or make.

It appears that what you're doing is what I think of as "high throughput" macro photography--a large number of standard shots, hopefully obtaining high quality with minimumal time invested in each shot. For that, my sense is that the less you have to mess with the specimen, the quicker your work will go. Further, if some of the museum's specimens are individually important, such as type specimens, then minimizing risk to the specimen becomes critical. To me, minimizing risk would avoid flipping horizontal mounts vertically, hundreds or thousands of times over, one mount at at a time. (This said, I'm not a bug guy, so what do I know? :D )

Cheers,

--Chris S.
Last edited by Chris S. on Sat Sep 21, 2019 5:42 pm, edited 1 time in total.

NikonUser
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Post by NikonUser »

I have got decent images with the insects at the base of a funnel:
http://nitro.biosci.arizona.edu/zEEB/bu ... toBox.html
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

proullard
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Joined: Thu Sep 19, 2019 7:44 pm

posing insects

Post by proullard »

Thanks to all who have contributed advice and suggestions as to how to solve the problem of arranging pinned insects.

What I came up with so far, is to photograph my subjects horizontally, pose the pinned insect on top of a small jackstand, which can be raised and lowered for height and stick the pin that goes through the insect into black modeling clay on a horizontal axis so that the dorsal view is facing the camera. There will be a black background against the insect. Once I have the photo in Photoshop I can deal with the clay and play with the intensity of the black background.

Any other suggestions are appreciated.

rjlittlefield
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Post by rjlittlefield »

For smaller specimens (higher magnifications), you'd really like to have fine control of framing on both axes. The jackstand only does one. Consider instead using an XY positioning system. MacroscopicSolutions.com uses something like this: https://www.edmundoptics.com/p/60mm-y-4 ... ge-/11782/ . Less precise but cheaper and with more travel are 2D macro rails like https://www.amazon.com/Neewer-Focusing- ... B009SJ7UWU. If you need longer travel with good precision, https://www.amazon.com/iShoot-Universal ... B01MZACMWY . Or for more precision, you can stack micrometer rails, rotary tables, and goniometers in the spirit of Chris S's Bratcam: https://www.photomacrography.net/forum/ ... php?t=8247 . Those can be assembled using modules from Edmund Optics or Thorlabs, or barring trade wars, their Chinese equivalents are a lot cheaper and equally good for your purposes.

The ability to quickly and precisely adjust angle may be surprisingly useful, if for no other purpose than to get that dorsal plane actually perpendicular to the lens. That's the purpose of the rotary table and goniometers in the Bratcam.

Normally I work vertical, but here I've reconfigured my kit to be horizontal, just to illustrate what I'm talking about.

Here the subject is positioned to shoot dorsal. I've dialed in 7 degrees of tilt to get exactly the view I want:

Image

Here's the same rig, with a second view having rotated the top to shoot lateral, with tilt zeroed out to show the goniometer at work. You should see this as a two-frame animation. Note that the fly is located at the center of rotation on both axes, so it stays centered in the camera's field as rotation is changed.

Image

The details of what equipment you need really depend on what you're photographing, and at what magnification.

To get more ideas, I suggest also to look through the assortment of setups that are linked at https://www.photomacrography.net/forum/ ... 5311#55311 .

--Rik

Chris S.
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Re: posing insects

Post by Chris S. »

proullard wrote:. . . stick the pin that goes through the insect into black modeling clay on a horizontal axis so that the dorsal view is facing the camera. There will be a black background against the insect. Once I have the photo in Photoshop I can deal with the clay and play with the intensity of the black background.

Any other suggestions are appreciated.
Phil,

Rik provided very good suggestions above. I'll add one simple thought: Between the clay and the insect (if you continue to use clay after reading Rik's post), you could place a flat, black or colored card, running the pin through the card. IIRC, this has been called "through pinning" or similar. If the card is black (perhaps covered with black flocking material), you will have a deep black background that may be acceptable on its own, or can be easily cloned out if it registers an even 255, 255, 255 rendering. If the card is covered with some color not present in your subject, you can select it in Photoshop (or your preferred pixel editor) and replace with the background of your choice.

--Chris S.

rjlittlefield
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Re: posing insects

Post by rjlittlefield »

Chris S. wrote:
proullard wrote:There will be a black background against the insect. Once I have the photo in Photoshop I can deal with the clay and play with the intensity of the black background.
Phil,
...
you could place a flat, black or colored card, running the pin through the card.
This discussion reminds me to prompt you to think about color standardization. While black, white, and colored backgrounds are all valuable in some cases, they provide little or no reference in the photo for what the color of the subject really was. If accurate colors are required for your application, then you might also consider using a true photo gray card for background, in addition to high CRI illumination.

--Rik

proullard
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Joined: Thu Sep 19, 2019 7:44 pm

dorsal view

Post by proullard »

Again thanks to everyone who has given me suggestions as to how to take macro photos of a subject on a horizontal plane with the camera.
I am also using tips from Sam Droege, who works for USGS. He has a very simple setup. He uses a jackstand with black clay and shoots the insects from a lateral point of view with a horizontal camera setup.
His images are extremely well done with his setup. Sometimes I think simple is best. All depends upon what results one wants, but still I could keep on buying more equipment that may or may not be necessary for what I want to achieve.

rjlittlefield
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Post by rjlittlefield »

Sam Droege's methods are well tested. If they meet your needs, that sounds like a great way to go.

--Rik

proullard
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Joined: Thu Sep 19, 2019 7:44 pm

Dorsal view

Post by proullard »

I do like though the small background for the leveling head. I did make one of those out of 3/8" plywood. I put black plasticene clay on the back and then covered that with black velvet. Pinned insects stay perfectly still in the clay on the horizontal axis I need.
Another solution to tilting in several planes is the Kirk leveling base, which may not be as precise as the Thor labs but still might serve the purpose. https://www.kirkphoto.com/tripod-monopo ... -base.html.
Much less expensive as well!

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