"Into The Light"
Go Extreme with your camera settings!
Low key refers to a style of photography that utilizes predominantly dark tones to create a dramatic looking image. Using your camera to achieve this effect not only produces a more dramatic and artistic image, also allows a similar moment or shot to be very different to what others may capture. Typically this is achieved by reducing the exposure or increasing the shutter speed (or narrowing the aperture). The idea is reduce the amount of light obtained to the sensor, and enhance the detail.
"But I can do this in lightroom or post processing" some may say. To some extent yes - you certainly can adjust the exposure and contrasts, however there are high chances that highlights will already be "blown out" meaning they cannot be recovered. There are many shades of white (and Black). Even in RAW, true white has no detail, and therefore cannot be recovered through adjustments. Black is Black and White is White, when you hit the extremes of your histogram. Post processing should be minimal to correct or enhance the captured image, to maintain a high quality photo. Extreme adjustments will likely cause excessive noise, artifacting or quality loss, so getting the shot right in camera first will minimise post production edits and maintain the highest quality image.
With subjects that have strong contrasts, playing with exposure can often lead to a dramatically different image. In this example a white sunlit, little egret, against fairly dark but uninteresting background - This case in point is the Grassy banks of the Chobe River.
Normal exposure getting the background also in frame could lead to loss of detail blowing the highlights of the egrets feathers, leaving a rather uninteresting shot, with a too "white" bird. (see the comparison below)
Taking advantage of a darker background - and the additional light that was reflecting on the bird from the water (as seen in the lower part of the egret), meant underexposing could blacken the background, but leaving enough detail on the bird to emphasise this creating a low key image.
Under exposing will naturally do any or all of three things, depending on the mode you shoot. Decrease ISO until it hits the lowest setting, decrease aperture (bigger F number) until it reaches the narrowest setting or increase shutter speed. In this case I wanted sharp wide aperture, Low ISO and a fast shutter speed (upwards of 1/6000s).
I chose to shoot in Aperture mode, I wanted F4 - which on the setup I used, is the sharpest scale and would give enough depth of field for the bird. Fixing ISO at 200 which is the Base ISO on the E-M1 chose to under expose by a full 3 stops. This gave a very high shutter speed of 1/10,000s but was enough to get the blackness I wanted whilst maintaining the detail of the bird - including a faint but visible outline of the black beak.
Body: Olympus OM-D E-M1 MKii
Lens: M.ZUIKO DIGITAL ED 300mm F4 IS PRO
Settings: ISO200 F4 1/10,000s @300mm EV-3.0
Centre Weight Metering, Aperture Priority
Tip: I took several shots at -1EV, -2EV -2.3EV, -2.7EV and -3EV to give me coverage and options so I could select the one that gave the effect I was looking for. Choosing the lowest exposure as the best result.
Slide your finger or mouse across the image below to see the difference using exposure compensation. These two images were taken in the same location within a few seconds. The normal exposure image doesn't show as much detail in the white areas, where the exposure has clipped the brighter whites. The under exposed shot shows more details and accents the finer shadows. Same bird, same scene very different results.