Guide to black and white photography 2 – Technical Essentials

This article aims to give some insight into the technical essentials and logic behind black and white photography and also tries to establish an overview of the commonly available methods for processing to black and white. It describes why a black and white photo is not a color photo with the colors removed, but that a color photo is originally a black and white photo with colors added to it. This will form an important premise for the further discussion of black and white techniques. I will discuss the pros and cons of commonly available methods and also take the available plugins into the equation. I won’t go into much detail on how to process black and white photos using the various methods, that’s outside the scope of this article. Furthermore, when processing to black and white I will start from another important premise that it’s about working with luminance differences, or differences in intensities of light.

Disclaimer: First off I need to state that unlike my earlier blogposts, my most recent blogposts don’t intend to provide you with tips or tricks, although some suggestions can be considered as such. My real intention is to provide you with information, preferably information that finds support in other scientific or artistic disciplines, so you can distil tips or tricks yourself instead of accepting them from me. So if you expect a quick and easy read, packed with tips and tricks then just forget about this article and try browsing the tons of other articles available on the Internet that try to enlighten you with tips and tricks. If on the other hand you appreciate neutral but hopefully valuable information based on my experience as a black and white photographer, then by all means enjoy the read.


In part 1 of this guide, ‘In Defense of Black and White Photography’, I wrote about why black and white photography could be used, and gave an overview of the artistic pros and cons of black and white photography compared to color photography. One of the conclusions in part 1 is that black and white photography is one step away from reality, which is a way of achieving beauty, necessary for art. Furthermore an elementary difference between color and black and white is that you can only perceive dimensional depth correctly when your view isn’t distracted by colors. Black and white is the ideal medium to create and perceive depth since it’s the art of working with luminosity differences to create a meaningful photograph. On the other hand, colors can add to the symbolism and mood in a photograph, which is a way of communicating a message in a photograph, necessary for it to be called art. In another article I wrote how you can combine the best or most valuable aspects of black and white photography with some of the most valuable characteristics of color, namely by working with split tones in a black and white photograph.

The article in front of you can be read without reading part 1 of this guide, but I would highly recommend reading part 1 for a better understanding of the artistic reasons behind black and white photography. This article is all about the technical reasons for a correct approach to black and white photography.

A black and white photo is not a color photo with the colors removed, but a color photo is originally a black and white photo with colors added to it.

From Black And White To Color And Back

Usually when we talk about converting to black and white we’re referring to the entire process from doing the basic conversion from color to black and white to the further processing of an image. It is important in the context of this article to separate ‘conversion’ from ‘processing’. Whatever phrase you prefer to use outside of this article, is entirely up to you, but I would recommend separating them to avoid confusion.

Conversion: the initial step to come from a raw color photo file to a neutral black and white version of it.

Processing: all other adjustments in photo editing software that doesn’t include a color to black and white conversion. Also applicable to color photographs. Of course.

The visuals are representing the following:

  •  Color is added through a CFA (Color Filter Array) that’s placed on the digital sensor – the sensor itself, only captures light, or better yet, luminance values, and are always without any color information. Photographic sensors such as CCD or CMOS sensors, can only capture light intensities and are, due to its nature, incapable of separating wavelengths, which basically is the actual color. Contrary to common belief, black and white is not a color recording with the colors removed, but color originally is a black and white recording with colors added through the use of a CFA such as a Bayer filter, that can separate the different wavelengths.

The Bayer filter is a physical layer placed on top of a CCD or CMOS photo sensor, containing a grid with a pattern of red, green and blue filters that can identify the various different wavelengths that represent the various colors. Each colored filter represents a pixel on a sensor and are literally placed on top of a pixel. In a Bayer filter there are always more green than red and blue filters since green filters are more sensitive, just like the human eye is more receptive for green. If for example light hits the red filter, it will only let through the red color component of that light and will discard the blue and green information. The discarded blue and green components will later be added through a demosaicking process that interpolates the missing colors to make up for a full color image. This implies that a color sensor will always miss 2/3 of the information per pixel that will later be guessed! The set of data, containing the red, blue and green data and the luminance values is the actual RAW data file and demosaicking is the process that takes place when we run a RAW file through the RAW converter in Photoshop for example. Despite the fact that demosaicking algorithms are very intelligent, it still is just an algorithm that can make very well educated and accurate guesses. Therefore it has its flaws that become more critical around edges of a photo and also in areas in an image where colors abruptly change. It is for this reason that a photographer working in black and white only, will benefit the most of a sensor that has no CFA and no interpolations will be part of the entire process.

  • There are various interpolations in the pure color process that are inevitable to produce a color photograph. The interpolations indicated in the red callouts cannot be avoided in both color and black and white workflows with a full color sensor. Note that I’m also referring to the addition of color through the CFA as ‘interpolation’, which some may argue this is not strictly interpolation. For the sake of this article I’m also calling this interpolation since it has an impact on the original data of recorded luminance values.
  • The interpolation in step 2 is inevitable with a full color sensor and consists of an algorithm that depends on the CFA used.
  • There are various interpolations in the black and white process that should ideally be avoided to achieve a good black and white photograph
  • The interpolation indicated in the blue callout in the black and white workflow can be avoided by choosing the right way of ‘converting’ the color image to black and white. With the right way I mean a neutral way of conversion that will leave intact the luminance values of an image and only removes the color information. The necessary adjustment of luminance values to express the artistic interpretation will then be controllable and individual and not the subject of algorithmic interpretation by the software. More on this further on in this article where I will discuss this in more detail.
  • In some cases, as is the case with pure monochromatic digital sensors like the Phase One IQ3 achromatic or the Leica M Monochrom, all interpolations are canceled out even the interpolation in the blue callout. The result out of such a camera is the most neutral and least subjected to algorithmic interpretations and the conversion to remove the colors is eliminated. This is the most ideal starting point for a black and white photograph. Of course such a camera comes with a price, but I believe there should be a place for a monochrome camera only, in the marketing strategy of all mainstream camera manufacturers and not only in the strategy of high-end camera manufacturers like Phase One or Leica.

Black and White Conversion Methods Overview

As stated earlier on in this article: with a black and white conversion I’m only referring to a method for making the actual one-off step, to come from color to black and white. The adjustments that take place after the image has been converted to Black and White, will be referred to as post-processing methods or steps. After all, you only need to make the step from color to B&W once, while post-processing steps can be done multiple times and always have as a goal to correct the luminance values.

What happens with most conversion methods is that they’re aiming to use the characteristics of a black and white photograph, namely the visible differences in luminance values, to create or suppress depth, while at the same time they’re selection criterion is its original color values. This is quite arbitrary since you change a luminance value based on a property, color, that gives no clear indication of its luminance value (see previous article) unless its stripped from its colors. And you may argue that in the end you’ll end up with the right B&W image anyway, so it’s irrelevant, but it’s simply a fundamentally wrong approach.

To minimise the number of interpolations  and to start with a neutral and ‘clean’ image, I’m suggesting here that the conversion method should preferably result in a neutral conversion without any luminance corrections that take place ‘behind the scenes’. Luminance corrections should only be part of the subsequent post-processing steps as an intended result.

Aim for an absolute neutral conversion that has no luminance corrections during conversion.

The overview of black and white conversion methods that is presented here can of course never be complete overviews since there are so many individual ways to create a black and white photograph from color and I surely won’t pretend I know all of them, nor do I want to discuss all of them. For every method I’ll try to select a representative set to get an impression.

Not part of this overview is an elaborate analysis of what the in-camera black and white conversion does, simply because there are too many cameras and more importantly: almost all of them, with the exception of a few that will be discussed here briefly, convert images to black and white in-camera to a JPG image. The same applies to all the apps and filters for mobile devices: I love what they can do but it’s also JPG. The quality of a JPG image is such that it’s not comparable to working with a RAW file and working in JPG will result in a loss of too much information that it’s simply not useful for high quality black and white post processing. But if you only want to use your photos for quick uploads to instagram or other social media and don’t intend to create fine art or other high quality images on printed paper, then that’s perfectly justifiable but then this article may not be for you.

Black and White Conversion Methods Photoshop

PS Feature (image>adj)Luminance Correction
B&W DefaultYes
B&W All Channels 0Yes
Channel MixerYes
B&W Gradient MapYes
Luminosity BlendingNo

Black and White Conversion Methods Photoshop Lightroom (LR) & Capture One (C1)

B&W Conversion LR and C1Luminance Correction
LR Black and White AutoYes
LR Black and White All Channels 0Yes
C1 Black and White All Channels 0Yes

Black and White Conversion Plug-Ins

Plug-InLuminance Correction
Silver Efex Pro 2 – NeutralNo
Silver Efex Pro 2 – Other PresetsYes
Topaz NeutralNo
Topaz Other PresetsYes
DXO Filmpack – Zero SettingsYes
B&W Artisan Pro – NeutralNo

As can be concluded from the overview of most used conversion methods, there are only a few ways to create a neutral Black and White result without any interpolation. There’s no default setting in the B&W conversion features in Photoshop, Lightroom or Capture One that will create a neutral conversion. All conversion methods are based on the original color channels and increasing or decreasing the color intensity for the desired black and white output. Of course it should be possible to adjust the color intensity in such a way it results in a neutral B&W conversion, but again, there’s no default setting for that, nor does ‘all channels set to 0’ result in such a neutral conversion. From the plug-ins that I have used only the neutral presets in SEP2 and Topaz will offer a black and white conversion without any luminosity corrections. Some may oppose that desaturation in Photoshop should result in a neutral conversion. Theoretically, desaturation of colors should indeed result in a neutral black and white image, but practically, in Photoshop, for example, desaturation is not neutral and it will change the luminance values.

*Edit July 2018* After releasing my B&W Artisan Pro panel, also this panel will create an absolute neutral conversion.

There’s one very easy way though in Photoshop by which you can create a completely neutral black and white conversion, the luminosity blending method, that I demonstrate in the 1-minute video below.