Colour to B&W Print

[Manfred M]

I thought I might share some of the work that I do as I prepare an image for a "large" format print.

I'm working on five different images right now that will be printed as 11" x 14" / A3 size.



1. Original colour image - of a Yampara boy I took about a month ago, while visiting Bolivia.






2. I generally do my B&W conversions by using Photoshop's Channel Mixer and set the values to R=30%, G= 59% and B = 11%. This corresponds to what we see when we set the camera to B&W mode and gives me a neutral base to start with. I generally do not use external tools like Silver Efex Pro when I prepare an image for print.






3. After doing my first test print and identifying areas that needed tweaking this is my first cut of where I want to go with this image. I'll be doing some more test prints to fine tune this image. Mostly this is burning and dodging andsome minor repair work to accentuate parts of the image and to downplay or eliminate distractions.

[DanK]

A nice, instructive example.

I do have one suggestion: lightly dodging the face and adding slight contrast to it. I would make it a subtle adjustment. I think that might help separate him from the background and draw the eye even more to the face.

[xpatUSA]

... 2. I generally do my B&W conversions by using Photoshop's Channel Mixer and set the values to R=30%, G= 59% and B = 11%. This corresponds to what we see when we set the camera to B&W mode and gives me a neutral base to start with.

Those setting coefficients look very close to the ones used for luma (Y') in JPEG conversion. Probably not a coincidence; in fact, some editors offer 'luminance' as one of several RGB-to-grayscale conversion options. See here for more about other methods:

https://en.wikipedia.org/wiki/Lightness

Quite a lot here too:

http://rawpedia.rawtherapee.com/Black-and-White_addon

See under 'Presets', but it's not Photoshop ...

[Manfred M]

A nice, instructive example.

I do have one suggestion: lightly dodging the face and adding slight contrast to it. I would make it a subtle adjustment. I think that might help separate him from the background and draw the eye even more to the face.

Thanks Dan.

I had already done a lot of dodging and burning on the face, but have done one more selection and added some mid-tone contrast to the entire face and I find that it does give the image a bit more pop. I think I'm just about ready to start the next set of test prints here.





The entire image has over 40 adjustment layers with 10 of them on just the face.

[Manfred M]

Those setting coefficients look very close to the ones used for luma (Y') in JPEG conversion. Probably not a coincidence; in fact, some editors offer 'luminance' as one of several RGB-to-grayscale conversion options. See here for more about other methods:

https://en.wikipedia.org/wiki/Lightness

Quite a lot here too:

http://rawpedia.rawtherapee.com/Black-and-White_addon

See under 'Presets', but it's not Photoshop ...

Thanks Ted - I was aware of some of the history, but certainly not to the level you are.

It's a fascinating subject with both historical, physical issues (i.e. NTSC colour television signals being played on B&W televisions), physiological (i.e. how the human vision system works) and psychological (i.e. to a large extent, what we are used to) aspects.

What is important to me is to have a solid base that I start with and to know it well so that I have consistent output. Regardless, the R + G + B values should add up to 100% to ensure we reduce the risk of clipping a specific colour channel (assuming some or all of the input values have not been clipped).

Right now, I am in one of my B&W phases, but suspect I will get back into working primarily in colour. I always do...