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Monday, 20 April 2020


Excellent post Mike! Thanks for sharing the link, insightful.

Aperture had the most wonderful channel mixer , which you could combine with slight amounts of sepia to shape tones to look just right, in a wide variety of styles.
I still use it. It is simple and powerful.

Great Post, TOP rules

I've found this set of channel mixer "recipes" for converting color photos to b&w film equivalents to be helpful: http://www.tjansson.dk/2012/11/photography-channel-mixer-rgb-values-equivalent-to-traditional-bw-film/

Tim Bradshaw's explanation is superb. Thanks! I may even have heard of that Albert guy, but I thought he was a clerk in a patent office. I didn't realize he also dabbled in physics. ;)

I do everything in Lightroom, and over the years have tried every way of converting to grayscale. I never liked the desaturation approach.

Nowadays I keep it simple: apply Adobe Monochrome camera profile and fine tune the colour channels.

Adobe's Monochrome camera profile (introduced in 2018 I believe) was a major step up compared to the approach used in earlier version of Lightroom. According to Julieanne Kost, "This profile slightly shifts colors as they are converted to grayscale – brightening the warmer colors and darkening the cooler colors. It also adds a small amount of contrast but allows lots of headroom for editing." It certainly works for me.

It took me a good hour of fiddling and looking at his overly quick instructional gif to figure out what he was doing in Photoshop (my skills are just above beginner in that program, so I kind of stumble around). But after I figured out how to make a solid color black layer, the results looked quite natural and pleasing with one portrait, with a "just right" look to the skin tone. I'll keep experimenting.

Addendum to Tim's addendum:

Tim mentioned dark adaptation in passing, but didn't go into any detail. The shift to blue sensitivity is a result of the physiology of dark adaptation involving the two primary photoreactive pigments in retinal cells. I hadn't thought of the photon energy threshold before (embarrassing as I'm also an astronomer by hobby and degree), but that's an important part of the relative spectral sensitivity of the various retinal pigments. Dark adaptation increases the eyes' relative sensitivity to blue light as a result of switching from predominantly using green-reactive rhodopsin in the color-sensitive (and bright light dependent) cone cells to preferring more blue-reactive pigments in the more light-sensitive but color-insensitive rod cells. This is known as the Purkinjie effect (https://en.wikipedia.org/wiki/Purkinje_effect). Apparently, the process involves a process akin to the binning that some digital cameras can perform in dim light.

As a further addendum, the photosensitive pigments in animals' eyes are close chemical relatives of chlorophylls and other phytochemicals in plants.

Here is a simple conversion using the Twitter method (black layer in color mode). I kind of like it, a sort of gentle conversion that maintains some fealty. On this one I only hit "auto exposure" in camera raw, something I normally don't do, then opened in Photoshop. You can click through to larger versions.

One of the first hard lessons I learned when going digital was that B&W was going to be difficult. Simply turning down the color produced flat, soulless pictures.
In the years since I have tried several B&W conversion plug ins and my favorite remains the first one I bought over a decade ago. It is B&W Styler from the Plug in Site.
It isn't a runaway. The conversion tool in PS is excellent and I have tried other third party converters and they all seem pretty good but B&W Styler is the one I know best and I am happy with what it does for me.
But what works for me may not be best for you.
A friend and one of the best photographers I know is Kent Sievers, a Fuji shooter and he told me he likes the Acros preset with a little touch up in both shadows and highlights. His B&W looks like Tri-X done right.
Also on the subject of B&W, Mrs Plews and I are using part of our confinement to take advantage of TCM and some streaming services to do a Film Noir marathon and it's wonderful.
We are hitting some of the less well known films of this genre and we are seeing some amazing photography. Here are a few that have really made me smile: Cry of the City, Naked City, He Walks by Night, Out of the Past and A Cry in the Night.
I don't suppose if is exactly Film Noir but Kurosawas masterpiece High and Low also has glorious photography. Panorama shooters can learn from this film too.
It is in widescreen and if you watch it you may notice that Kurosawa makes sparing use of close ups. Instead he uses lighting and composition to direct your eye. It is also interesting to watch how he makes use of the entire frame. Often important elements of the story take place on the very edge of the image. Also instructive is his choice of focal lengths in a widescreen film. For the most part the lenses are moderate to slightly long.
I think the genius of this film is that it feels like three films in one to me. It starts out with a character study set almost entirely inside a house then switches to a great police procedural and tucked away in all of this is a scene in a drug alley that is the best short zombie movie ever made.
I wonder how many anime directors have that sequence committed to memory. Good stuff.
But I digress.
In digital I try to limit my fiddling with my pictures to what I could do (or hoped I could do) in the darkroom.
As it turns out getting a OK color print is much easier in digital than in the darkroom but black and white is proving to be quite a challenge. Go figure.

In digital, I set the camera to B&W to visualize, and RAW to have later if I need it. In film, I sometimes check the scene with my iPhone set to B&W, and maybe even take a reference shot, since I may be using the Lightmeter App anyway to get the exposure range.

I solved the color to b&w conversion problem via the purchase of a Leica M262 Monochrom.

I set the viewfinder of my camera (Olympus OMD) to "monotone".
My results are way better this way, it helps a lot the composition.

Good grief Charlie Brown, doesn't anyone understand how to use LAB Color Space to obtain a "perfect" BW conversion?


Thanks, Frank! That's what I get for typing too much. I was mis-recalling from long-ago biology class about similar molecular structures in chlorophyll and oxygen-ferrying molecules like hemoglobin and hemocyanin. Mea culpa.

This is how you do this in ImageMagick:

convert color.jpeg -colorspace LAB -channel R -separate bw.jpg

This converts the image to LAB space and then uses the LAB lightness channel to create the black and white image.


While not disagreeing with Tim Soret's point, I can't help but feel that he is taking aim at a straw man or woman. As a number of other commenters have noted, it's certainly the case that taking the luminosity channel in Photoshop will give you a B&W conversion with an apparent brightness and contrast that fairly closely match that of the source colour image. Which is what you're doing by using his 21xR + 72xG + 7xB weights. I say "fairly closely", because I don't always like what that approach does to skin tones, which can end up a bit dark.

But B&W is an abstraction, and surely the point is to get the most pleasing B&W conversion / abstraction. Desaturate may well give it sometimes. The luminosity channel may do so far more often. But there is a close-to-infinite number of ways to convert to B&W in Photoshop. You can't try them all on every image, but it's worth exploring some of them to get a sense of what approach suits what type of image. I think that desaturate vs luminosity is a false dichotomy that conceals far more (ways of converting to B&W) than it reveals.

Which, given your current voyage of discovery into Capture One, raises the related question of which raw converter is best to convert colour to B&W, if you convert at that stage rather than in PS? Lightroom and C1 have similar conversion tools featuring R,G,B,C,M,Y sliders, but LR adds orange and purple. You'd think that this would be better because it allows more precise targeting of colours to tweak in the conversion. Am I the only one who thinks that these eight sliders are too narrow with not enough overlap? I often get artefacts at colour boundaries, especially under artificial light. I think the C1 B&W tool is better for this reason. But even so, PS conversions allow more flexibility and more options.

Absolutely fascinating Mike. Much appreciated Mike,the other Mike, Tim, Frank and everyone.

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