Affinity and Full Spectrum Processing

[Richard Pring]

I have just started experimenting ! I have a Panasonoc FZ100 adapted for full spectrum. I have  UV/IR, 680and 950 fiters. If I take  jpeg photos they look as expected. If I open in Affinity 2, the UV/IR images look normal visible images, but the images using the other filters have a strong blue cast. Channel swapping still maintains blue cast. What am I missing/doing wrong?

Would 590 or 720 filters be more succesful.

 

Thanks

[Old Bruce]

Be aware that all the visible and invisible light will hit the tiny sensors which make up the large sensor. And all the tiny sensors still have their Red, Green (x2), or Blue filters on them.

The tiny little individual sensors in the actual camera have a colour filter over them. One will have a Red filter, two will have Green filters and the fourth will have a Blue filter, times however many "pixels" your sensor has. Your modified camera has had its High Cut and Low Cut filter removed, this filter fits over the entire large sensor and removes the Infrared and Ultra Violet* light. The UV light will go through the Blue filter quite easily, the IR light will pass through the Red filter quite easily.

If you use the 680/950 filter the light from the scene will hit the filter and only IR light will pass through to the lens and sensor. The UV filter I am not sure about, is it a High Pass or High Cut filter, meaning is it letting only UV light through (High Pass) or is it filtering out the UV light (High Cut)? 

What are you wanting? The IR light will be captured by the Red sensors, the UV light will be captured by the Blue sensors.

 

*not Ultra Violent (stupid Otto Korect™)

[Richard Pring]

Thanks for your detailed reply.

I understand the function of the theory. My problem is that when I view an image in "My Pictures" taken with an IR filter on the camera, the "colouir " is modified as expected. If I then open this image with Affinity, the image given then  has a strong blue cast. However, if I then export this image, the saved image is the same colour balance as the first image.

Why does opening in Affinity not give the same  as that in "My Picvtures"?

[Old Bruce]

I am unfamiliar with the Panasonic camera you are using. Perhaps there is some colour balancing going on inside the camera and this is what is making the JPEGs it is saving look odd/off/wrong.

My experience is in using an IR filter on my unmodified Canon and the camera saves as raw files, not JPEGs. Your additional removal of the UF filtering could be the cause, could be part of the cause.

I don't know what your reference to "My Pictures" is. There could be further processing going on there, I honestly don't know.

Try some pictures saved as raw in the camera.

[Richard Pring]

Thanks foradvice - I will try what you say.

[Dan C]

On 4/3/2024 at 7:46 AM, Richard Pring said:

Why does opening in Affinity not give the same  as that in "My Picvtures"?

Affinity is a fully colour managed application, meaning your images will be displayed using colour profile conversion, based on your documents profile and screen profile, set in your OS.

"My Pictures", assuming you're simply referring to the Folder where your images are saved and the built-in OS Image viewer is not colour managed, meaning the images are usually displayed as 8bit sRGB, regardless of the source file or your monitor settings.

You can find out more about colour management in Affinity here -

https://affinityspotlight.com/article/display-colour-management-in-the-affinity-apps/

https://affinity.help/photo2/English.lproj/index.html?page=pages/Clr/ClrProfiles.html&title=Colour management

I hope this clears things up!