The elementary clarification of overexposure is when a print comes out lighter than we intended, and that sounds like it ought to be something that’s utterly easy to repair with an image-editor like Photoshop or Lightroom.
That’s not always a case, however, and it’s all since of a approach digital camera sensors constraint images. They do this regulating particular photosites (or pixels) that collect light (photons) that is afterwards converted into an electrical vigilance for processing.
Why can’t we repair it later?
The there’s a extent to a intensity, or brightness, of light that these photosites can capture, so in a really splendid partial of a design a camera will only record a vacant white tone. In technical terms, these areas are pronounced to be ‘clipped’.
You see this a lot in high-contrast scenes, where blue skies infrequently come out as a pale, washed-out cyan color, or pale skies only seem a plain white. That’s since these areas are overloaded – overexposed – and it’s no good perplexing to redeem this fact after in program since it’s only isn’t there (although we can redeem highlights in reduction exceedingly overexposed images if we fire tender – some-more on this below).
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So we do have to be clever to equivocate overexposure in digital photography. This is really conflicting to a aged days of analog film, where underexposure was a large problem. Because of a approach film reacts to light, it was comparatively easy to scratch behind splendid detail, though shade areas were formidable or unfit to redeem since there’s no detail. Digital sensors are a conflicting – we can mostly redeem extraordinary amounts of fact from a shadows, though overexposed areas are left for good.
How can we forestall it?
It’s not formidable to forestall overexposure if we know what to demeanour for and when it’s expected to happen. You can check your camera’s histogram display, possibly in live perspective mode or in playback mode, and if a right-hand side of a histogram is abruptly chopped off, that’s an denote that a design has poignant areas of overexposure – utterly mostly we can see this in a saved design even but a histogram display.
You can put this right by regulating a camera’s exposure compensation control to revoke a exposure; by swapping to a conflicting metering system, such as centre-weighted metering, that gives some-more importance to splendid areas; or by indicating a camera during a brighter partial of a scene, requesting a bearing close and afterwards reframing to take a picture.
Part of a problem is that complicated multi-pattern metering systems are really sophisticated. and really good during ‘reading’ a stage to make certain that darker tools of a design aren’t mislaid in shadow. They’re designed to broach a design that ‘looks about right’, rather than one with a full operation of prominence tones.
You should also fire tender files rather than JPEGs, since tender files enclose some-more prominence (and shadow) information compared to JPEGs, and many tender acclimatisation programs will let we entrance this extended picture information and redeem ‘blown’ highlights. In bearing terms, we can typically redeem adult to 1EV of additional prominence detail.