EXPOSE HIGHCONTRAST SCENES
Master complex exposure calculations to ensure accurate and reliable capture of highlight and shadow detail
A guide to ensuring accurate capture of highlight and shadow detail
Many digital cameras are now capable of capturing detail across a brightness range of up to 15EV, generating data in the lightest and darkest parts of a scene. However, ultra-high contrast, such as that found in midday lighting, can still pose a major challenge, where the light intensity falls outside of the camera’s native dynamic range. In these circumstances, Evaluative metering will most likely be unable to reliably suggest an ideal exposure to balance all tones. Spot metering will help with perfecting either shadows or highlights, but will be unsuitable in wider-framed compositions. Generally, in these conditions, it is better to use multiple metering options, to gain an estimated range of possible settings and then tailor these manually.
While this style of working is slower than relying on automatic exposure control alone, taking the time to monitor shadows, midtones and highlights individually will ensure you generate a file with recoverable information at each end of the tonal scale. This method allows for maximum detail in a single frame, without merging multiple bracketed images in software. Often you will find that the photo appears too bright or too dark in-camera, but by combining these steps with the popular ‘exposing to the right’ technique, you can output a more usable file for later processing.
1 GENERAL METERING Begin by using Evaluative (or Matrix) metering to gain a rough indication of the type of settings that will be necessary. Take a reading from an ‘average’ area of the scene and note the suggested settings.
2 TIGHTER METERING Switch to CentreWeighted or Spot metering and take readings from highlight, midtone and shadow areas in turn. Compare these values with the initial ones to identify ‘problem’ areas to monitor closely.
3 SWITCH TO MANUAL Move to manual mode on your camera’s mode dial and enter settings close to that of the ‘best’ frame from the previous step. Manual will ensure the camera doesn’t change exposure as you recompose your shot.
4 OBSERVE THE HISTOGRAM Use live histograms when utilising Live View mode, or display an overlay during review, to check that no tones touch the sides of the graph. Also note whether the distribution of tones is as even as possible.
5 USE HIGHLIGHT/SHADOW WARNINGS These are good for quickly indicating whether there are any large areas of missing highlight or shadow detail. While histograms are more precise, visual warnings rapidly show general exposure accuracy.
6 PUSH THE EXPOSURE Once the exposure is ‘centred’, with good detail guaranteed, increase the exposure in order to move more tones to the right of the histogram, for optimal colour and quality. Work in 1/3-stop increments for precision.
AFTERGREATER CONTROL By measuring highlights, shadows and midtones separately, then using manual, the ideal exposure can be locked in, free from unexpected changes by the metering system
BEFORE Inset BLEACHED HIGHLIGHTS Evaluative metering is confused by the large shadow areas, resulting in over-compensation in the highlights,which are void of retrievable detail