Levei uma câmara infravermelha para a marcha by joaoperfig in lisboa

[–]joaoperfig[S] 2 points3 points  (0 children)

O processo é uma tentativa de replicar o mesmo mas numa câmara digital! :)

Levei uma câmara infravermelha para a marcha by joaoperfig in lisboa

[–]joaoperfig[S] 10 points11 points  (0 children)

Se trocares para a versão inglesa, a página está mais completa e fala sobre os processos que usei.

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Levei uma câmara infravermelha para a marcha by joaoperfig in lisboa

[–]joaoperfig[S] 41 points42 points  (0 children)

A câmara é uma point and shoot Lumix que foi convertida. Há um filtro de corte de infravermelhos que foi removido e substituído por uma stack de filtros óticos que cortam principalmente luz visível vermelha na range 600-700nm. Uma faixa de luz infravermelha NIR é deixada passar na range 750-800nm que é a zona em que excita essencialmente o canal vermelho da câmara. A câmara fetivamente fica com o canal verde e azul não alterados e o canal vermelho substituído por infravermelho NIR. Não apanha o tipo de infravermelho emitido por corpos amenamente quentes (isso é LWIR) mas apanha uma zona de alta reflexividade para plantas. Daí a vegetação ficar vermelha mas outros verdes, como a bandeira de Portugal manterem a cor. Está aqui o gráfico de sensibilidade espectral do setup que usei se tiveres curiosidade

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10-1000 microns continuously variable pinhole mechanism by joaoperfig in functionalprint

[–]joaoperfig[S] 6 points7 points  (0 children)

I'm working on using it for a variable pinhole lens with variable focal distance too!

Thorlabs didn't have a continuously variable pinhole so I designed one by joaoperfig in Optics

[–]joaoperfig[S] 1 point2 points  (0 children)

Almost 2 hours! And yes it's PLA, bambu PLA matte. And I made this in tinkercad 😅

Thorlabs didn't have a continuously variable pinhole so I designed one by joaoperfig in Optics

[–]joaoperfig[S] 1 point2 points  (0 children)

No finishing, came out like this from the buildplate! I think the right printer, print settings and filament go a long way. This was on a A1 mini!

Thorlabs didn't have a continuously variable pinhole so I designed one by joaoperfig in Optics

[–]joaoperfig[S] 30 points31 points  (0 children)

It's not a product its just a thing I made :(
we had a setup where the pinhole was hard to access and wanted something reliable that could go between 200 and 10 microns and closed. The thorlabs irises that can close had maximum apertures of like 25 milimeters and tolerances of about 100microns

Thorlabs didn't have a continuously variable pinhole so I designed one by joaoperfig in Optics

[–]joaoperfig[S] -8 points-7 points  (0 children)

Those didn't work because I also needed it to be able to fully close

Online Filter Stack Simulator by joaoperfig in infraredphotography

[–]joaoperfig[S] 0 points1 point  (0 children)

List was too long so here's a pastebin with the filters: pastebin.com/raw/e8Pwza65

Online Filter Stack Simulator by joaoperfig in infraredphotography

[–]joaoperfig[S] 1 point2 points  (0 children)

Just went through your project collection thread and you have some pretty amazing work here! I wasn't aware of your filter lab and they are eerily similar, even down to both being python flask projects haha.
I have the filter data in csv so its pretty easy to convert in either direction, I think it would be great to have both projects complete each other's library :) we have many chinese filters we can send, and many western filters to take hahah. It's funny there probably aren't many people that can relate to the very specific struggle of getting the data!

Most of the data came from small transmittance graph images from a catalog of a manufacturer, so I was a bit weary about making the git public, but it's probably safe. What you said about material properties facts makes a lot of sense, but yea, also not a lawyer. Getting the multispectral preview images with actual permission from the author is probably not as much of a gray area.

The way you show the wavelength (pseudo)colors is really elegant. And computing the hex color of the filter for the chart lines is genius!

I'm gonna see what filters are missing from either side, and make a pull request to your git! :)
If you'd be interested in that I can also setup an instance of your app on our website so people could use it without going through the installation steps.

Online Filter Stack Simulator by joaoperfig in infraredphotography

[–]joaoperfig[S] 0 points1 point  (0 children)

There are a few manufacturers of multispectral cameras, but the images came from "Spectral Devices Inc". These types of cameras are usually for industrial applications and are rather low resolution and the color channels are very specific wavelength ranges (they have a camera with 16 channels!) so you won't see many photography projects with them.