Infrared photo + RAW + PS5 = Pink filter - RAW Shooting and Processing - CHDK Forum
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Infrared photo + RAW + PS5 = Pink filter

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Offline JMarques

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Infrared photo + RAW + PS5 = Pink filter
« on: 03 / May / 2014, 21:41:08 »
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Hi everyone!

So i have a canon A1200 (with chdk 1.00C ) converted to infrared and i have a wierd issue when i try to convert from .dng to .tif in PhotoShop 5.

Example:


(Left image is a .dng and i get the wierd pink filter, right image is a .jpg and its perfect)
(White Balance was 'made'' by me, specific for this type of photo using a blue cardboard as a reference)

Anyone knows what can be the problem? Solutions?  :-X

Thank you!



« Last Edit: 03 / May / 2014, 21:54:15 by JMarques »
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Offline reyalp

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #1 on: 04 / May / 2014, 00:41:24 »
Quote from: JMarques on 03 / May / 2014, 21:41:08
Anyone knows what can be the problem? Solutions?  :-X
There is no problem with the DNG, it just records what the sensor saw. Since you removed the IR filter, it sees something different than it did before. What exactly that is depends on how the bayer filter elements respond to IR. The fact that it's pink probably means that the red pixels now pick up a lot of IR.

The "correct" rendering of this situation is a purely aesthetic choice.

If you can compensate for this in the jpeg with white balance, you should be able to do the same in raw processing software for the DNG.
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Offline JMarques

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #2 on: 04 / May / 2014, 08:13:11 »
Quote from: reyalp on 04 / May / 2014, 00:41:24
Quote from: JMarques on 03 / May / 2014, 21:41:08
Anyone knows what can be the problem? Solutions?  :-X
There is no problem with the DNG, it just records what the sensor saw. Since you removed the IR filter, it sees something different than it did before. What exactly that is depends on how the bayer filter elements respond to IR. The fact that it's pink probably means that the red pixels now pick up a lot of IR.

The "correct" rendering of this situation is a purely aesthetic choice.

If you can compensate for this in the jpeg with white balance, you should be able to do the same in raw processing software for the DNG.


The .jpeg you see up there is untouched, is what the camera records to the SD card. I didnt process anything
 
I still think there's a bug in my PS when i open the .DNG file.

I tried to open the .dng in Picasa and it works, check the attachment. I have the correct colors. So my PS is bugging something.  :blink:

(I have a #2007 filter inside the camera for capture NDVI - http://publiclab.org/wiki/near-infrared-camera)

Thanks for replying!


edit. tried to open in RawTherapee (Attachment) and the result is a little bit better then PS, but still not like the original .jpg, so i guess this is the PS and RawTherapee auto adapting their one color profiles. I dont want then to auto adapting anything. ffs :P
« Last Edit: 04 / May / 2014, 08:43:23 by JMarques »
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Offline waterwingz

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #3 on: 04 / May / 2014, 09:27:41 »
Spent a few fascinating minutes at the site you linked, including the section about using PS.

Most of the images I've seen online where the camera's IR filter has been removed / modified look like this :


Which is much like your PS image.  I assume what you are thus trying to do in PS is change the colors so that they look like visible light only?

Strange that your jpg does not show any effect from the IR filter - or did you do something to make that happen?

I do have a question here :  can you provide any details ( pictures maybe ?) of how you modified your A1200?

Update : found this how-to modify the A1200
« Last Edit: 04 / May / 2014, 09:40:42 by waterwingz »
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline JMarques

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #4 on: 04 / May / 2014, 09:43:37 »
Ofcourse!!!

A1200 disassembly - http://youtu.be/T_BPTSfttWU

A1200 disassembly - http://publiclab.org/notes/patcoyle/11-6-2012/canon-a1200-ir-conversion-november-2-4-2012-plots-barnraising-cocodrie-la-l

A2200 have almost the same body so its almost the same - http://publiclab.org/notes/nedhorning/9-25-2012/canon-a2200-nir-conversion

If you wanna make some NDVI shots you will need a #2007 filter for that A1200 (CCD Sensor) - http://store.publiclab.org/collections/diy-infrared-photography/products/infragram-diy-filter-pack


i'm in a bit of a hurry, i will answer to the rest of your questions as soon as i get back!

Thanks once again and have fun disassembly your A1200  :D (very very easy)
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Offline waterwingz

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #5 on: 04 / May / 2014, 09:55:18 »
Quote from: JMarques on 04 / May / 2014, 09:43:37
Thanks once again and have fun disassembly your A1200  :D (very very easy)
I happen to have two A1200s so using CHDK and something like this :
  http://publiclab.org/wiki/stereo-camera
or this
  http://publiclab.org/notes/gustrow/04-05-2014/mapping-the-nvcc-campus-using-a-flower-pot-as-a-camera-rig
with one camera modified and the other not modified seems ideal for NDVI image work.

There is even a tutorial on doing the image processing in GIMP
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline JMarques

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #6 on: 04 / May / 2014, 12:49:11 »
Quote from: waterwingz on 04 / May / 2014, 09:27:41
Most of the images I've seen online where the camera's IR filter has been removed / modified look like this
Which is much like your PS image.  I assume what you are thus trying to do in PS is change the colors so that they look like visible light only?

Strange that your jpg does not show any effect from the IR filter - or did you do something to make that happen?

I do have a question here :  can you provide any details ( pictures maybe ?) of how you modified your A1200?

Update : found this how-to modify the A1200


I just need PS to convert from .dng to .tiff, i dont want to do any editing.

My .jpg shows the correct image with the iR + filter #2007!

The problem is that i ''need'' .tiff (i can use the 3 bands (IR/G/B) with the .tiff / with the .jpg i only can use 1) for using the images in a specific program (Idrisi) to do a NDVI. I know there are alots of ways to make a NDVI but i as a remote sensing guy i do it from .tiff images and not .jpg. ;)

Using .jpg (see the attachments) is ok but i lose alot of detail and i cant edit as i want it.

I really need to find the reason for the pink filter in the .dng using ps. argh!


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Offline waterwingz

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #7 on: 04 / May / 2014, 13:20:37 »
Quote from: JMarques on 04 / May / 2014, 12:49:11
I just need PS to convert from .dng to .tiff, i dont want to do any editing. My .jpg shows the correct image with the iR + filter #2007!
If I understand your original post correctly,  you set a custom WB up in the camera prior to taking the image. Is that right?   That makes the JPG look "normal" as the camera applies the WB setting prior to saving the file as a JPG.

But the DNG image is saved by CHDK prior to the camera applying any WB settings.   What you see in the image is exactly what the camera sensor "sees".   I think that the pink color is to be expected as you are exposing the sensor to a lot more IR than it would normally see.

If you don't correct the WB in the DNG image using PS (or something else) then the TIFF will look pink too.

Have I missed something here ?
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline JMarques

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #8 on: 04 / May / 2014, 13:46:43 »
Quote from: waterwingz on 04 / May / 2014, 13:20:37
Quote from: JMarques on 04 / May / 2014, 12:49:11
I just need PS to convert from .dng to .tiff, i dont want to do any editing. My .jpg shows the correct image with the iR + filter #2007!
If I understand your original post correctly,  you set a custom WB up in the camera prior to taking the image. Is that right?   That makes the JPG look "normal" as the camera applies the WB setting prior to saving the file as a JPG.

Yes i have set a custom WB.

Quote
But the DNG image is saved by CHDK prior to the camera applying any WB settings.   What you see in the image is exactly what the camera sensor "sees".   I think that the pink color is to be expected as you are exposing the sensor to a lot more IR than it would normally see.

If you don't correct the WB in the DNG image using PS (or something else) then the TIFF will look pink too.

Have I missed something here ?


The wierd thing is that i think this is a PS bug.

With UFRaw is possible to see the .dng the same way as .jpg. Check the attachments.

''WB da camara'' = WB of the Camera
''WB manual'' = WB Manual



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Offline waterwingz

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Re: Infrared photo + RAW + PS5 = Pink filter
« Reply #9 on: 04 / May / 2014, 13:56:11 »
Quote from: JMarques on 04 / May / 2014, 13:46:43
The wierd thing is that i think this is a PS bug.  With UFRaw is possible to see the .dng the same way as .jpg. Check the attachments.
I think I get it now.   UFRaw reads the white balance settings out of the DNG EXIF information and applies them.  But PS does not. 

Not having PS,  I'm afraid I can't help further.  Seems possible there should be a setting in PS somewhere that tells it to use the DNG WB info?
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Ported :   A1200    SD940   G10    Powershot N    G16
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