TPE Vacuum Mesh

Images taken in a controlled environment or with a posed subject. All subject types.

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J_Rogers
Posts: 87
Joined: Mon Aug 09, 2021 2:29 pm
Location: North Carolina, USA

TPE Vacuum Mesh

Post by J_Rogers »

Originally wanted to photograph a spider & use these as a backdrop, creating a pseudo web. The mesh size ended up being too large for what I envisioned, so naturally I ditched the spider and found these make quite a nice image in and of itself.

These are Gel-Pak Vacuum Release trays, which are quite common in the semiconductor world for shipping fragile parts. If you have never seen one before I suggest looking up the video "How to unload devices from a VR-Tray" to see one in action. Incredible invention. At some point maybe a separate thread needs to be branched off this one in the equipment discussion but the company makes some ultra small mesh sizes for smaller parts. The one I have is labeled: VR-44-33CC-00B-XL meaning a mesh size of 33 which is one of the largest meshes they make. See here ->https://www.gelpak.com/vacuum-release-tray-user-guide/ . The 195 & or the nano tray may be an extremely economical high resolution test target.

Images are at 5x using a reversed Zeiss Distagon T* 28mm f2 @ either f2.8 or f4 (I can't remember).
Cross polarized light from two separate speed lights to image the filaments under the top layer of gel.
mesh1-web-version-1.jpg
mesh1 web version2.jpg
mesh2-web-version-1.jpg
mesh2 web version2.jpg

rjlittlefield
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Re: TPE Vacuum Mesh

Post by rjlittlefield »

Nice pictures, very interesting material that is totally new to me.

I'm missing the application as a high resolution test target. The spec is lines per inch, so 195 is only 7.7 lines/mm. The nano tray, https://www.gelpak.com/nano-device-tray/ , seems not to use a finer mesh, but a different method that avoids the mesh.

Can you explain the test target idea in more detail?

--Rik

J_Rogers
Posts: 87
Joined: Mon Aug 09, 2021 2:29 pm
Location: North Carolina, USA

Re: TPE Vacuum Mesh

Post by J_Rogers »

rjlittlefield wrote:
Tue Oct 26, 2021 4:49 pm

Can you explain the test target idea in more detail?
Well, not in the traditional sense of l.p./mm but at minimum something that is both flat and has varying depths (weaves on the mesh) for DOF. The grid would allow repeated tests for chromatic aberration and field curvature. And then the micro structures on the mesh would be able to measure sharpness etc. A stretch from actual targets but when you look at price per one it is rather cheap.

I initially thought they weren't using the mesh for their nano trays too, but if you look on their page discussing the technology they mention it contains a mesh as well as a diagram. So the question I had was just how thin are the filaments in the smallest trays. I measured roughly 350 micron on mine with give or take 1mm space square to the next one. If the filaments get thinner with the higher mesh sizes in theory the 195 or nano has ultra fine structures on them that could be used as a gauge for sharpness etc. Not scientific, but at ~ $20-$30 per it perhaps could be something along the lines as a "forum target", something with fine enough detail that different members could compare their lenses & objectives to. I know the idea gets brought up from time to time with the resulting answer either being availability, price, or repeatability / accuracy across targets.

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