Trichrome effect in Photo

[johnk]

I have seen a technique referred to as "trichrome" where the photographer took three exposures of a scene on black and white film. One with a green filter, one with a blue and one with a red. He then scanned them and brought them into photoshop as greyscale images and used a command called "merge channels". The result is an RGB image. 

I'd like to duplicate this effect with 3 digital RGB images; using the red channel from one, green from another and blue from the third.  Ive experimented with stacks and just a layered document with no success. Does anyone know how to achieve this?  

link to the video:  

 

[firstdefence]

Had a bit of a doodle, it's kind of a glitch effect.

 

[Walter Rowe]

Keep in mind that raw digital image files are captured in gray scale with a mosaic of red, green, and blue filters in a "bayer pattern" over the sensor.

https://www.sciencedirect.com/topics/engineering/bayer-pattern

A true RGB image is created by approximating the missing two color channels for each pixel using the surrounding pixels. This process is called "demosaicing".

X-Trans (Fujifilm) sensors have a different RGB filter pattern over the sensor but conceptually works in a similar way.

If you really want to simulate this process with a digital camera you need a truly monochrome sensor like the Leica M Monochrome series or PhaseOne Achromatic.

[johnk]

14 minutes ago, Walter Rowe said:

Keep in mind that raw digital image files are captured in gray scale with a mosaic of red, green, and blue filters in a "bayer pattern" over the sensor.

https://www.sciencedirect.com/topics/engineering/bayer-pattern

A true RGB image is created by approximating the missing two color channels for each pixel using the surrounding pixels. This process is called "demosaicing".

X-Trans (Fujifilm) sensors have a different RGB filter pattern over the sensor but conceptually works in a similar way.

If you really want to simulate this process with a digital camera you need a truly monochrome sensor like the Leica M Monochrome series or PhaseOne Achromatic.

Ok so I use a M monochrome and colored filters (although why not make greyscale images from the RGBs for each channel?).......... how do you take those three greyscale images and make an RGB? 

[johnk]

19 minutes ago, firstdefence said:

Had a bit of a doodle, it's kind of a glitch effect.

 

Thats about as good as I go. was hoping for better. 

[Walter Rowe]

6 minutes ago, johnk said:

Ok so I use a M monochrome and colored filters (although why not make greyscale images from the RGBs for each channel?).......... how do you take those three greyscale images and make an RGB? 

The video you posted demonstrates telling the software which image to use for which color channel. I don't know how to tell Affinity to do that. At the 3:40 mark (3 min 40 sec) the person in the video uses Photoshop and selects an option called Merge Channels that lets them select which image is used for each channel.

[johnk]

3 minutes ago, Walter Rowe said:

The video you posted demonstrates telling the software which image to use for which color channel. I don't know how to tell Affinity to do that. At the 3:40 mark (3 min 40 sec) the person in the video uses Photoshop and selects an option called Merge Channels that lets them select which image is used for each channel.

I think I stated all of that im my original post. 

[v_kyr]

See also related ...

• How To Create The Tricolour Effect In PS

• Color Efex Pro has Bi-Color filter

• Filter Forge has Tri-Color filters

And for the cam ...

[Old Bruce]

In the digital world you don't need to worry about the filters. No need for Greyscale Leicas. Just take three photos in colour. Make a new document and add the Red channel from the first photo, the Green from the Second photo and you get the drift. It is the time between the shots that make it "Glitchy". In the real world of B&W film we have to remember that Panchromatic film is not evenly/equally sensitive to Red, Green, and Blue light. And, it can be difficult to find Red, Green and Blue filters that will work. Then comes the processing, not going back there. ... Hell, I don't even know what the pH for my local water is.

[johnk]

1 hour ago, Old Bruce said:

In the digital world you don't need to worry about the filters. No need for Greyscale Leicas. Just take three photos in colour. Make a new document and add the Red channel from the first photo, the Green from the Second photo and you get the drift. It is the time between the shots that make it "Glitchy". In the real world of B&W film we have to remember that Panchromatic film is not evenly/equally sensitive to Red, Green, and Blue light. And, it can be difficult to find Red, Green and Blue filters that will work. Then comes the processing, not going back there. ... Hell, I don't even know what the pH for my local water is.

How exactly do you add one channel from one photo to another? (Make a new document and add the Red channel from the first photo)

[johnk]

1 hour ago, N.P.M. said:

https://www.youtube.com/results?search_query=glitch+effect+in+affinity+photo

Thanks, this isn't exactly what I want. I'm hoping that by using three images slight movement  (blowing leaves, running water, etc) will have that so called "glitch" effect and everything else will not

[NotMyFault]

You don't need any filters if you after the glitch effect.

1. Just take 3 photos with a defined time gap between captures.
2. Create new stack from 3 images.
3. The use channels panel to clear out 2 of 3 color channels, leaving one intact. So top R, middle G, bottom B
4. set blend mode to "add"
5. Move layers out of stack.

You can boost the glitch with transform panel, liquify, perspective filter etc.

[johnk]

5 minutes ago, NotMyFault said:

You don't need any filters if you after the glitch effect.

1. Just take 3 photos with a defined time gap between captures.
2. Create new stack from 3 images.
3. The use channels panel to clear out 2 of 3 color channels, leaving one intact. So top R, middle G, bottom B
4. set blend mode to "add"
5. Move layers out of stack.

Please go into more detail about step three, exactly what should I do?

[Walter Rowe]

3 hours ago, NotMyFault said:

You don't need any filters if you after the glitch effect.

1. Just take 3 photos with a defined time gap between captures.
2. Create new stack from 3 images.
3. The use channels panel to clear out 2 of 3 color channels, leaving one intact. So top R, middle G, bottom B
4. set blend mode to "add"
5. Move layers out of stack.

You can boost the glitch with transform panel, liquify, perspective filter etc.

He isn't trying to get the glitch effect for the entire image. He wants a color image where only things that moved between frames show the glitch effect. See read the original post.

[NotMyFault]

4 hours ago, Walter Rowe said:

He isn't trying to get the glitch effect for the entire image. He wants a color image where only things that moved between frames show the glitch effect. See read the original post.

My recipe delivered colors only in areas where objects moved, and stays otherwise B&W. Maybe you could try it before declaring me wrong?
 

[NotMyFault]

Here you find an older example with even non-destructive workflow.

the edges color band is caused by perspective alignment for handheld shots of the three images.

This process works for color images. You can convert them to greyscale (simply add a vibrance or HSL adjustment) or use greyscale images if you like to get greyscale.

trichrome.afphoto

[NotMyFault]

Bonus: B&W applied to color images to simulate B&W source images.

you see all static areas like buildings get B&W, whereas moving objects like water and ferry get colored.

 

Edited January 15, 2023 by NotMyFault
typos

[NotMyFault]

CMYK Bonus: The same method works perfectly.

You need to use

1. 4 images
2. blend mode "linear burn" instead of add

to mix CMYK colors.

[Walter Rowe]

11 hours ago, NotMyFault said:

You don't need any filters if you after the glitch effect.

1. Just take 3 photos with a defined time gap between captures.
2. Create new stack from 3 images.
3. The use channels panel to clear out 2 of 3 color channels, leaving one intact. So top R, middle G, bottom B
4. set blend mode to "add"
5. Move layers out of stack.

You can boost the glitch with transform panel, liquify, perspective filter etc.

I had to read over this again. I understand how you are removing 2 of 3 channels.

What if they are starting with a set of three truly monochrome digital images that were taken with R, G, B filters as described in the video?

[johnk]

6 hours ago, NotMyFault said:

Here you find an older example with even non-destructive workflow.

the edges color band is caused by perspective alignment for handheld shots of the three images.

This process works for color images. You can convert them to greyscale (simply add a vibrance or HSL adjustment) or use greyscale images if you like to get greyscale.

trichrome.afphoto

HAZZA! Thanks for the file download, it helped me figure out how to adjust the channel mixer layers..... and it worked!!  Thanks!!

[NotMyFault]

3 hours ago, Walter Rowe said:

I had to read over this again. I understand how you are removing 2 of 3 channels.

What if they are starting with a set of three truly monochrome digital images that were taken with R, G, B filters as described in the video?

it simply works.

There might be a theoritical minor difference in using colour filters in front of your camera lens vs. doing it in post. But this is a creative workflow without any claim of scientific accuracy.

If you want to capture one single B&W image, you can't divide the image into 3 colour channels later (except using AI or manual colouring). But for trichromatic look, we take 3 images, and we apply new artificial colouring, based on sequence. Not identical, but similar enough and suitable for the use case.

If you have still doubts - why not use your own existing images, or capture some nice photos, and try it out on your own?

[Walter Rowe]

21 minutes ago, NotMyFault said:

it simply works.

There might be a theoritical minor difference in using colour filters in front of your camera lens vs. doing it in post. But this is a creative workflow without any claim of scientific accuracy.

If you want to capture one single B&W image, you can't divide the image into 3 colour channels later (except using AI or manual colouring). But for trichromatic look, we take 3 images, and we apply new artificial colouring, based on sequence. Not identical, but similar enough and suitable for the use case.

If you have still doubts - why not use your own existing images, or capture some nice photos, and try it out on your own?

I appreciate your patience and the sample file you provided. That helped a lot. I now how it works. With three monochrome images where each has frame had an R, G, or B filter over the lens so that each frame captures just one channel, this process should work identically. For the blue frame, turn down the R and G channels, and do likewise for the other frames. Set the base frame to Normal blend and top two frames to Add blend mode.

Thanks again!