How to simulate colour (yellow, red, green, etc.) filters on a Monochrom image.

[jaapv]

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Copy of a post in the Monochrom forum.

 

It is exceedingly simple in Photoshop CC 2023:

Go to Neural Filters, activate Colorize and go to Image -> Adjustments -> Black and White. You can simulate any colour filter you like.

 

It does not really matter if the colourization is a bit funny.

[250swb]

Even better you can also make a full colour image from monochrome files (B&W film or digital set to B&W) and not simply colourise individual exposures. You need to make three RGB exposures, one with a red filter on the lens, one with a green filter, and one with a blue filter. You can then go to Photoshop and colourise each shot RGB in the sequence you shot them. Then all you need to do is make three Layers of your RGB exposures, reduced the transparency of each to 33% as a starting point, and combine them until the image becomes a satisfying full colour image. You have created your own colour photograph.

Provisos are the three images should be able to be stacked accurately or registration will be off. If anything moves in the photograph, person, cloud, etc. it will be shown as the primary colour of the filter that was on the lens at the time, so good for funky effects, but a still life is ideal. You need a tripod, yes I know, as a Leica user you don't use them.

[jaapv]

Photoshop Colorize Neural Filter replaces this more than 100 year old technique to create full colour images, and to be honest, despite some weird mistakes, mostly makes a pretty good job of it. So no need any more to move to Russia. 

[jaapv]

In fact, I am planning to restore a number of old family photos with Neural Filters. First double the resolution with Gigapixel, then use the Restore Neural Filter to clean them up and recreate a proper tonal curve and then turn them into colour photos in Colorize, remove artifacts and run Topaz Photo AI over them. I’ll post a few results in due course. 

[Michael Geschlecht]

39 minutes ago, jaapv said:

Photoshop Colorize Neural Filter replaces this more than 100 year old technique to create full colour images, and to be honest, despite some weird mistakes, mostly makes a pretty good job of it. So no need any more to move to Russia. 

Hello Jaap,

It is not only the Tsar of Russia, who hired a photographer & gave him a suitably equipped railroad train & a plethora of assistants: Who could have color photos made on black & white film. Around World War II, & for a while after, a person could buy a "tri-color camera", which is sometimes called a "one shot camera".

These cameras used the "magic of mirrors" to take 3 different black & white photos. Each thru a different color filter. Each onto a different piece of black & white negative film. All 3 being exposed thru the same lens with the same shutter, at the same time. The resulting 3 different negatives, printed appropriately, produced a very nice color photo.

Best Regards,

Michael

Edited May 22, 2023 by Michael Geschlecht

[250swb]

5 hours ago, Michael Geschlecht said:

 

These cameras used the "magic of mirrors" to take 3 different black & white photos. Each thru a different color filter. Each onto a different piece of black & white negative film. All 3 being exposed thru the same lens with the same shutter, at the same time. The resulting 3 different negatives, printed appropriately, produced a very nice color photo.

 

Which is how Technicolor worked in its infancy.

[jaapv]

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Gentlemen, a historical overview is not the purpose of this thread and quite OT. . Mr. Prokudin-Gorsky is well known and has been regularly discussed here

This thread is about having a simple,  fast and effective method to apply colour filters  to a Monochrom image, like one does to a Bayered and converted one. This is, after all, a subforum dedicated to digital postprocessing. 

So. To get back on topic:

Go to Neural Filters, activate the Colorize switch, go Image->  Adjustments;Select Black and White to restore your monochrome image and you will find that it behaves exactly the same as a converted image and that the Photofilter colour sliders work, Thus eliminating the need for colour filters on the camera. with the added advantage of doing local adjustments, which, with the new selection tools is extremely easy and fast. 
 

All in all, a few seconds work. 

[250swb]

It just not very accurate yet, often hit and miss, areas in and around details are often missed or misinterpreted. In terms of re-writing history though, well I’m against it. 

[jaapv]

Which is completely irrelevant for the purpose of simulating colour filters. I am not for or against any PS setting. I use them as applicable. You may have missed the latest update. Adobe has upgraded their selection algorithms. 

[pop]

One of the more prominent genealogical sites (myHeritage) has been offering this function for your family shots for quite a while. I don't know if it's any good, though, as I've never put it to a test.

[jaapv]

Indoor shots of people are surprisingly  good in PS,  although the colour of clothes etc is obviously guesswork.