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I wonder what would happen if..

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#1 Fandyus

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Posted 08 April 2021 - 08:32

I wonder what would happen if someone made a full spectrum camera that had actual high quality filters on the bayer array, as in, the green would be a proper bandpass that doesn't let in any IR, the blue would be a proper UV+blue+violet pass filter that also doesn't let through IR and the red filter could honestly stay the same. Perhaps some UV blocking could also be implemented onto green and red as I suppose those let through UV because UV images taken with a converted camera display chromaticity. Does anyone here perhaps own a debayered camera with a set of filters like I described so that a trichrome could be done this way? I have done some experimentation with this myself but it wasn't amazing:
red channel is with a 950nm longpass filter by GREEN.L
green and blue channels are extracted from a second image taken with a QB39 BG39 IR cut filter manufactured by Tangsinuo which actually works surprisingly well, even IR from incandescent bulbs is filtered off to the point where I haven't noticed it in my images.
Attached Image: FandyusResize.jpg


That being said, I wanted to upload more images but I found out that I blew my entire upload quota on my introduction post because I though the limit was 30mb per post, not per account. I apologize, I sometimes forget what exactly "global" means in a given context (english isn't my first language). Am I out of luck? Something I can do to mitigate this? I'm really sorry.
Edit: Issue is now solved. I hereby thank the admins.

Edited by Fandyus, 08 April 2021 - 23:44.


#2 nfoto

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Posted 08 April 2021 - 09:11

We can increase your upload state of course, however it is prudent to understand there is no need to upload full-sized images to every post. If everyone behaves thuslike our server would quickly run out of storage space. There is a major difference between file sizes given in MB and mb, alas. Do keep in mind Andrea and I provide a free service to the UVP community, and absorb the associated costs which are manageable, but definitively not zero.

Usually an image size of maximum 2000 pixels on the long axis will be more than enough and in fact, half the size probably suffices for most posted images. The admins won't police the postings to monitor the behaviour of posted images, unless our attention is drawn to an occurring issue.

I suggest we *delete* the images in your introduction thread and replace with a text stating the images were too big. Then, start another topic in which you repeat your first post however now with properly resized images. We can then move the remaining posts in the original thread to merge with the new one. The time window for editing your original post has closed, thus we need to follow a more awkward procedure here. It's OK for once, but please adhere to better posting practice hereafter.
EDITOR'S NOTE: I downloaded and resized the image. :grin:

#3 Fandyus

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Posted 08 April 2021 - 10:16

Yes, I am really sorry, I uploaded large images for reasons stated. I will repost my introduction with properly downsized images, thanks for being understanding. I will make sure to downsize my images in the future.

#4 nfoto

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Posted 08 April 2021 - 10:19

I suggest an alternate approach in a PM to Fandyus. Anyhow we will be able to get out of the current upload gridlock.

If you still can edit your post, then there is no need for further intervention by the admins, however. Confirm by PM that you can achieve this, otherwise follow the solution I oulined in PM to you.

(despite rumours to the contrary, I have been young once myself, and know life is error-prone. One learns by committing errors)

#5 dabateman

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Posted 08 April 2021 - 11:11

The camera you are describing is very close to an off the shelf Sigma Foveon sensor. The dust blocker would block everything under 410nm and most of the IR. The blue, green and red depths were calibrated for those colors. But really all depths saw all the colors, and it was complicated unmixing and calibration that resulted in the images. But amazing images with true yellow.
Many are still awaiting for the Foveon L-mount camera.
But if you remove that blocking dust filter. Than the blue channel sees UV. The red channel is all IR and the grenn depth is interesting. With my SD14, I was able to do one shot UV reflectance in blue channel, UV induced visible fluorescence in green channel and UV induced infrared fluorescence capture in the red channel.
I still need to play more with it.
But Sigma cameras can also be a challenge.

#6 Andy Perrin

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Posted 08 April 2021 - 15:54

I usually use 1100px or 1000px width images, and whatever aspect ratio makes sense for the image. I like the above image very much, it's a gorgeous picture with nice colors.

Regarding monochrome cameras, my TriWave is monochrome and never had a Bayer to begin with. It does have some UV sensitivity, but I've never pushed it. I know it does fine around 365nm with a torch. The biggest problem is the 640x480 resolution on that one. I don't know how far it extends in the short short waves. Unlike in the other direction, Germanium remains a good photon absorber down to 200nm. (The limit in the other direction is that Ge becomes transparent around 1700nm.)

Also, several members have debayered Raspberry Pi cameras. Andrea has a monochrome Leica. Jonathan has a nice collection of cameras in all states of "bayerness" including partially removed...

I did some tricolor IR images with the TriWave (hah!) back here:
https://www.ultravio...tri-color-snow/
https://www.ultravio...80-830-1064-nm/
https://www.ultravio...dpost__p__32318

Edited by Andy Perrin, 08 April 2021 - 16:13.


#7 Andrea B.

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Posted 08 April 2021 - 19:10

EDITOR'S NOTE:
Fandyus - I downloaded your image and resized it to 1200 pixels width.
You are good to go for a while. :grin:

Eventually when you do run out of space, then we will move you to the next level.

Looking forward to seeing more of your work.
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#8 Fandyus

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Posted 08 April 2021 - 23:28

View Postnfoto, on 08 April 2021 - 10:19, said:

I suggest an alternate approach in a PM to Fandyus. Anyhow we will be able to get out of the current upload gridlock.

If you still can edit your post, then there is no need for further intervention by the admins, however. Confirm by PM that you can achieve this, otherwise follow the solution I oulined in PM to you.

(despite rumours to the contrary, I have been young once myself, and know life is error-prone. One learns by committing errors)
Hey, thank you a lot for being understanding and taking care of the posts and such. I hope I did not cause you much inconvenience.

#9 Fandyus

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Posted 08 April 2021 - 23:30

View PostAndrea B., on 08 April 2021 - 19:10, said:

EDITOR'S NOTE:
Fandyus - I downloaded your image and resized it to 1200 pixels width.
You are good to go for a while. :grin:

Eventually when you do run out of space, then we will move you to the next level.

Looking forward to seeing more of your work.
Thank you for your kind words, I will make sure to post my results often - in proper size of course. :)

#10 Fandyus

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Posted 08 April 2021 - 23:36

View PostAndy Perrin, on 08 April 2021 - 15:54, said:

I usually use 1100px or 1000px width images, and whatever aspect ratio makes sense for the image. I like the above image very much, it's a gorgeous picture with nice colors.

Regarding monochrome cameras, my TriWave is monochrome and never had a Bayer to begin with. It does have some UV sensitivity, but I've never pushed it. I know it does fine around 365nm with a torch. The biggest problem is the 640x480 resolution on that one. I don't know how far it extends in the short short waves. Unlike in the other direction, Germanium remains a good photon absorber down to 200nm. (The limit in the other direction is that Ge becomes transparent around 1700nm.)

Also, several members have debayered Raspberry Pi cameras. Andrea has a monochrome Leica. Jonathan has a nice collection of cameras in all states of "bayerness" including partially removed...

I did some tricolor IR images with the TriWave (hah!) back here:
https://www.ultravio...tri-color-snow/
https://www.ultravio...80-830-1064-nm/
https://www.ultravio...dpost__p__32318
Ah yes, I've actually seen your trichromes already and I'm a fan, especially the one with the pepper is interesting, you should definitely do more of those :)
Thanks for liking my image, I would do more trichromes but it would almost be worth it to invest into some magnetic adapter for filters, constantly screwing and unscrewing filters is a pain I must admit. Also, thanks for telling me about all the monochrome cameras people here own, looking forward to see their future results.

#11 Stefano

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Posted 08 April 2021 - 23:38

As of trichrome/tri-color images, you can either use filters (like Andy and Bernard did) or use different light sources (like I did). It depends on what you need to image.

#12 Fandyus

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Posted 08 April 2021 - 23:39

View Postdabateman, on 08 April 2021 - 11:11, said:

The camera you are describing is very close to an off the shelf Sigma Foveon sensor. The dust blocker would block everything under 410nm and most of the IR. The blue, green and red depths were calibrated for those colors. But really all depths saw all the colors, and it was complicated unmixing and calibration that resulted in the images. But amazing images with true yellow.
Many are still awaiting for the Foveon L-mount camera.
But if you remove that blocking dust filter. Than the blue channel sees UV. The red channel is all IR and the grenn depth is interesting. With my SD14, I was able to do one shot UV reflectance in blue channel, UV induced visible fluorescence in green channel and UV induced infrared fluorescence capture in the red channel.
I still need to play more with it.
But Sigma cameras can also be a challenge.
I have heard of the wonders that a foveon sensor can achieve. I would definitely like to own one someday. I'll be sure to check your account to see.

#13 Fandyus

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Posted 08 April 2021 - 23:41

View PostStefano, on 08 April 2021 - 23:38, said:

As of trichrome/tri-color images, you can either use filters (like Andy and Bernard did) or use different light sources (like I did). It depends on what you need to image.
I have actually tried both, there's definitely a lot of space for experimentation. Hopefully I'll get to posting soon :)