Blog Post

Photo Editing - Black and White Conversion

Derek Smith • 15 February 2021
monochrome portrait of a female
For those among you that are looking to obtain a new image editing suite, Affinity Photo 1.9 is currently retailing at a 50% discount, meaning a one-off licence is only £23.99, which must be a bargain.

Today, with the March PDI competition of “Monochrome”, and “Open” in mind I would like to demonstrate how to convert a colour image to black, and white.

Starting with a basic colour card created in Affinity Photo and viewing the range of different colours on the colour card in the HSL sliders, pure black has 0% Saturation, and 0% Luminosity. Pure white has 0% Saturation, but 100% Luminosity. All other colours between black, and white have 50% Luminosity, and 100% Saturation, with only the hue slider varying to give the different colours.

Converting this colour card to black and white in Affinity Photo does not give the expected result. The colour card displays only the black bar, with the remainder of the card showing white only, and the HSL colour channel sliders default to 50%, so, why is this?

The human eye perceives colours in different brightness levels, blue will naturally appear darker than green even though the luminosity, and saturation remain the same, photo editors display colours scientifically, rather than as our eyes perceive the colours. This of course creates issues when converting colour images to black and white.

Most of the teaching videos I have looked at for black and white conversions advise “wiggling the HSL sliders until it looks right”, not very scientific, is it? So, how do photographers ensure consistency in converting colour images to black and white? Luckily for photographers there is a scientific formula for colour conversion to black and white. This formula was derived during the early days of colour television cameras in the 1950s to give the same relative brightness to each of the colours when viewing on a black and white television.

This formula is red = 30%, yellow = 89%, green = 59%, cyan = 70%, blue = 11%, and magenta = 41%.

To scientifically adjust the black and white conversion simply apply the formula to the HSL sliders and the black and white conversion is scientifically complete. Save this formula as a pre-set in your favourite photo editing suite, and this will make an excellent starting point for black and white conversion, now you have only to make fine adjustments to the HSL sliders for personal editing choices.

With the portrait photo of Leah Maraki successfully converted to black and white, all that is needed is to boost the contrast, and reduce the exposure to obtain a perfect result.

Learn something new every week, stay safe, and enjoy your hobby.

Louth Photographic Society

by Graham Harrison 12 January 2025
Good Morning All I have been out and about working and have seen quite a lot of flooding out at Brandy Wharf and frost at Linwood warren. We start back at the club this Wednesday 15th, after our Christmas break. We start with a PDI competition, with the categories of "shadows" and "open" to be judged by Steve Chapman. The following week is project night when you can show what you did for last year's project which was numbers. Regards Graham
by Derek Smith 8 January 2025
How has your photographic life been this year? I’ve been out taking photographs, but mainly for my own pleasure, and enjoyment. The weather at the start of the year seems to have been wetter, and cooler, warming up later, and this weather pattern has influenced the photos for wildlife. Our club outings to wildlife reserves produced little in the way of insects. My photographic genre of choice is for model photography, and I’ve chosen to work more in studios this year producing a good, but not exceptional body of work. Equipment wise, I’ve stayed with my Fuji camera system, and the various lenses. My only change was swapping the Fuji XF 50mm f/2 lens for the TT Artisan 56mm f/1.8 lens, and the main reason for this was the Fuji lens has a lightly damped, although clicked, aperture ring, and I kept jogging the aperture ring during shooting. I’m certainly enjoying the TT Artisans lens; the slightly longer focal length produces a nicely blurred background, and I intend to use it for more subjects than just as a pure portrait lens. Highlights of the year, well definitely the holiday to Menorca, the nature reserve on the island was literally “alive” with insects and wildlife in stark contrast to the UK. The Empsay and Bolton heritage steam railway, near Skipton, was another delight. Staying for 2 nights at the Cow and Calf Inn on Ilkley Moor, enabled me to photograph the sunset, and sunrise over the moor. In 2025 I want to take more landscape, and creative images, reducing my bias toward portraiture photography.
by Graham Harrison 5 January 2025
Good Morning All I hope you all had a good new year. Thinking I might take a nice winter scene photo this morning, but just a bit of wet snow and rain. We start back at the club a week on Wednesday (15th) with a PDI competition, Shadows and Open, I f you can send your entries to Harry by midnight next Wednesday please. Regards Graham
by Derek Smith 2 January 2025
Hopefully everyone has had a good Christmas, and perhaps enjoyed partying into the New Year. We'll soon be back to normal at the club on Wednesday 15th January, when we hold our first competition of the year, a PDI, with the categories of "Shadows", and "Open". Travelling into Lincoln today, taking advantage of the sunshine, I had my Fuji X-S20 camera with me and the 56mm f/1.8 TT Artisans prime lens, (85mm full frame equivalent), walking around with this small lightweight combination, enjoying taking various photos. Indoors now, and looking at the images, my decision is made, I shall be using the 56mm lens for the "Prime Time" annual project, a fixed focal length prime lens challenges the photographers creative compositional skills. The TT Artisans lens was inexpensive at £160, and produces great image quality, as can be seen from some of these images.
by Graham Harrison 29 December 2024
Good Morning All I hope you have all had a good Christmas. I tried to find one image to sum the year up and came up with this one taken at Whitby, overcast and rain. Not much to report, just to remind you to prepare your PDI's for the next competition on January 15th, with the categories of "Shadows" and "Open", and send them to Harry when as soon as you're ready. The new project will be starting soon as well, one photograph a month using the same prime lens for all photographs. If you only have zoom lenses just set it to the same focal length each time. Regards Graham
by Derek Smith 28 December 2024
The 2024 project was “Numbers”, one photo that included a number for each month of the year, I have just finished my last photo for this month, it has been an interesting project. Our 2025 project is “Prime Time”, one photo each month taken with the same prime lens, (a lens with a fixed focal length). Yesterday I was out visiting the Alice in Wonderland experience at Castle Howard, Yorkshire, I took one camera, the Fuji X-S20, with a Sigma 30mm f/1.4 prime lens to capture some images. Having a fixed focal length certainly makes a photographer concentrate on composition but consider that many iconic photographs from the 20th century were taken in this fashion. My 30mm lens on an APS-C camera is the equivalent of 45mm on a full frame camera, the lens is considered a “normal” focal length. For this project I would probably use my wide-angle Samyang 12mm f/2, (18mm full frame) which I normally use for architecture, or landscape photography, I could also use the TT Artisans 56mm f/1.8 (85mm full frame) portrait lens, either lens would challenge my photographic skills, and I will choose in the next week or so. Photographs taken at Castle Howard with a Sigma 30mm prime lens.
by Graham Harrison 23 December 2024
Good Morning All Last Wednesday we held our annual Buffet and quiz night including Harry's raffle. I think you would all agree we had a very good night, and I must thank all our members for donating so many raffle prizes. Thank you also to my partner Jane for preparing the buffet, Dave Mann for sorting the buffet out and making the drinks and Harry who ran the raffle and read out the quiz prepared by Paul Malley. Thank you Paul for compiling the quiz for us. We now have our Christmas break and when we return on January 15th we start with the monthly PDI competition, Shadows and Open. You can send your entries to Harry after the new year to give Harry a break, it will give us something to do over the festive season. Have a great Christmas. Regards Graham
by Derek Smith 20 December 2024
This was the last meeting of the year, and we celebrated the evening with a delicious buffet provided by Graham's partner Jane, and there was plenty of food for members attending the evening, with some members taking leftovers home. Paul Malley was unfortunately unable to attend owing to ill health, but, he had prepared a general knowledge quiz, with some very obscure questions, which kept us puzzled, and entertained, Tony Gaskins scored the most points, and took the prize cup. Members had brought in items for the raffle, Harry Kerman sold the tickets, and the raffle raised £47 for club funds. Overall it was a very successful evening. So, a big thank you to Jane for the buffet, Paul for the quiz, Harry for running the raffle, and Dave Mann for laying the buffet out, and preparing refreshments. A date for your 2025 diary: Saturday 22nd February there will be an opportunity to photograph a Taekwondo event; details to follow. Wishing all our readers, and members a very Happy Christmas.
by Graham Harrison 15 December 2024
Good Morning All Last week at the club we held our monthly print competition judged by Ron Abbott, as usual there were some really good prints on show and all the results are on our website. This week we are holding our Christmas buffet, quiz and raffle night, so don't have too much to eat before you attend as there will be plenty to eat. Paul Malley is organising the quiz and Harry the raffle, please bring a raffle prize on the night if you would be so kind. You can also bring a drink of beer or wine if you wish, or Dave will be boiling the kettle. Christmas jumpers optional. Regards Graham
by Graham Harrison 8 December 2024
Good Morning All Last Wednesday we were treated to an excellent talk and PDI show by Gavin Smith a very keen aviation photographer. Gavin had a very personal approach to photographing planes getting in closer than we may do and showing incredible detail in his photographs. There is more about Gavin on our blog. I also tried re - editing one of my photographs to get more detail which is the Kittyhawk attached. This week, Wednesday 11th December, we will hold the monthly print competition, with the categories of "Events" and "Open" to be judged by Ron Abbott. The following week it is our Christmas buffet and quiz night, were has the year gone? Harry will be holding a Christmas raffle, could members bring some donated prizes in on the night please. Regards Graham
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