To “See” in Black and White, a question of exposure
One of the first difficulties in taking B&W images is how to visualize in monochrome, for those used to mostly colour work it is difficult to remove the colour one sees and interpret the scene, but if you can train the eye to think mono, life becomes easier and the production of striking B&W images is made that much easier, to get a basic understanding of this you must think in grey tones, and how the data is transmitted to the camera sensor, and what is actually happening when you press the shutter. Ansel Adams devised a way of precise control over exposure called the Zone System this was assuming that the camera, film and developing of the negative where all calibrated correctly, in this way he could determine where the tonal range would be in the image, this gave him the ability to set a mood for the picture, as an example, imagine a scene with wonderful fluffy white clouds against a blue sky if you were to take an average reflected meter reading the whole image would be just another sky and cloud picture with no feel or drama, that may be OK in colour but not in mono, we need to add drama and effect and this can be done using exposure as the tool, I will explain anymore about the Zonal system as this was primarily devised for film, the developing of negatives was an inherent part of the system, because we use digital now that part is missing, but it’s important to understand the basic principles, so I will try to explain how to visualize and use exposure as a tool for setting the mood in B&W imagery.
First we must understand how all camera meters work whatever the setting. Auto-Semi Auto-Programme-Manual, the meter will set the correct exposure for a given scene based on thousands of sample exposure scenes within the cameras’ micro-processor, for your average snapshot this is fine for scenes of average tones in front of the meter, but as soon as the tones are biased towards dark or light that’s when things go wrong, the reason being all in built meters are calibrated to produce 18% grey or “middle grey” all other tones are then moved up or down to represent the scene in shades of grey, look at example 1 below this was a piece of black card, I set my DSLR in auto mode with no compensation, the black card has turned out mid grey, in example 2, again with the camera set to auto no compensation and the white card has turned out mid grey.
It can be seen that the two exposures although different give nearly the same result, middle 18% grey, the camera auto metered for the Black card has given a longer exposure to turn it grey, and a shorter exposure for the white card to turn that grey, in example 3 below I have split the image into black and white, the black is better but the white is still greyish, what can be seen from the exposure values on example 3 is that the camera has tried to average the exposure to come up with the best result.
So what does this tell us, all three exposures are wrong to produce the correct tonal range, that’s because we have let the camera take control and not the photographer, now if we have established what is happening and know the camera will always turn white and black to middle grey we are well on the way to understanding how it will affect our images, lets take the examples 1 and 2 above, to turn the black card to a true black the exposure would need to be compensated by at least 3 full stops less and the white card compensated by 3 full stops more, in other words we would have to slide the shades of grey up or down from a given middle grey point.
Look at the grey scale below the background scale is the cameras representation of white, Tone 1 is middle grey, the smaller scale is the exposure compensation required to bring the white card to true white by overriding the cameras settings we have moved the tonal range up the scale.
So lets now see what happens to the card at different compensation settings.
+ 1 full stop
+ 2 full stops
+ 3 full stops
- 1 full stop
- 2 full stops
- 3 full stops
So how does this work in practical terms, take the examples below of a landscape picture, I was aware that auto would not deliver the exposure I wanted, so I bracketed the shots to move the grey scales up and down to reveal better highlight and shadow detail, the examples are all straight from Raw files with no editing applied.
The above exposures give me plenty of tones to play with in Photoshop, example 1 has given a nice middle tonal range, example 2 has moved the grey-scale down to bring out more cloud detail, example 3 has moved the grey-scale up to reveal shadow detail and provide more contrast to work on, it’s worth mentioning that different scenes will require varying amounts of compensation dependent on the intensity of the light.
Below is the finished image edited as my other tutorials in the "learning zone".
To “see” in B&W does take some getting used to, but if you can follow the principle of the grey-scale and try to understand what is happening when you meter with your camera you will be able to produce shots not thought possible, using the grey-scale method blacks will be deeper, whites cleaner and a range of mid tones in-between the two, you will also be able to dramatically change the mood of the image which is so important in monochrome by deciding if you want the image to be low-high key, contrast can be reduced or increased, even in these high tech times I would suggest using a handheld light meter that measures incident light (incident light meters measure light falling on the subject or scene not reflected from it) readings are rarely fooled by dark or light areas and give a correct starting point for exposure plus there are EV scales on them to “read” the exposure.
From the above I hope you have a better understanding of how exposure affects the look and mood of a picture and helps you to think and see in grey-scale.
First we must understand how all camera meters work whatever the setting. Auto-Semi Auto-Programme-Manual, the meter will set the correct exposure for a given scene based on thousands of sample exposure scenes within the cameras’ micro-processor, for your average snapshot this is fine for scenes of average tones in front of the meter, but as soon as the tones are biased towards dark or light that’s when things go wrong, the reason being all in built meters are calibrated to produce 18% grey or “middle grey” all other tones are then moved up or down to represent the scene in shades of grey, look at example 1 below this was a piece of black card, I set my DSLR in auto mode with no compensation, the black card has turned out mid grey, in example 2, again with the camera set to auto no compensation and the white card has turned out mid grey.
It can be seen that the two exposures although different give nearly the same result, middle 18% grey, the camera auto metered for the Black card has given a longer exposure to turn it grey, and a shorter exposure for the white card to turn that grey, in example 3 below I have split the image into black and white, the black is better but the white is still greyish, what can be seen from the exposure values on example 3 is that the camera has tried to average the exposure to come up with the best result.
So what does this tell us, all three exposures are wrong to produce the correct tonal range, that’s because we have let the camera take control and not the photographer, now if we have established what is happening and know the camera will always turn white and black to middle grey we are well on the way to understanding how it will affect our images, lets take the examples 1 and 2 above, to turn the black card to a true black the exposure would need to be compensated by at least 3 full stops less and the white card compensated by 3 full stops more, in other words we would have to slide the shades of grey up or down from a given middle grey point.
Look at the grey scale below the background scale is the cameras representation of white, Tone 1 is middle grey, the smaller scale is the exposure compensation required to bring the white card to true white by overriding the cameras settings we have moved the tonal range up the scale.
So lets now see what happens to the card at different compensation settings.
+ 1 full stop
+ 2 full stops
+ 3 full stops
- 1 full stop
- 2 full stops
- 3 full stops
So how does this work in practical terms, take the examples below of a landscape picture, I was aware that auto would not deliver the exposure I wanted, so I bracketed the shots to move the grey scales up and down to reveal better highlight and shadow detail, the examples are all straight from Raw files with no editing applied.
The above exposures give me plenty of tones to play with in Photoshop, example 1 has given a nice middle tonal range, example 2 has moved the grey-scale down to bring out more cloud detail, example 3 has moved the grey-scale up to reveal shadow detail and provide more contrast to work on, it’s worth mentioning that different scenes will require varying amounts of compensation dependent on the intensity of the light.
Below is the finished image edited as my other tutorials in the "learning zone".
To “see” in B&W does take some getting used to, but if you can follow the principle of the grey-scale and try to understand what is happening when you meter with your camera you will be able to produce shots not thought possible, using the grey-scale method blacks will be deeper, whites cleaner and a range of mid tones in-between the two, you will also be able to dramatically change the mood of the image which is so important in monochrome by deciding if you want the image to be low-high key, contrast can be reduced or increased, even in these high tech times I would suggest using a handheld light meter that measures incident light (incident light meters measure light falling on the subject or scene not reflected from it) readings are rarely fooled by dark or light areas and give a correct starting point for exposure plus there are EV scales on them to “read” the exposure.
From the above I hope you have a better understanding of how exposure affects the look and mood of a picture and helps you to think and see in grey-scale.
