Dynamic Range

[jeff791107]

Hello everyone,

I am curious about the significance of a one-stop or half-stop difference in a camera’s latitude. Does this discrepancy make a substantial impact? One camera has 16 stops, while the other has 15 stops. Does the former significantly outperform the latter?

Topic

[Roger Deakins]

There is a lot more involved than dynamic range when it comes to a camera’s performance but wider dynamic range does have a substantial impact on the image. Now, whether your particular scene needs that kind of range is another question and one only you can answer.

[dmullenasc]

The thing with dynamic range is that you don’t always need a lot of it… until you do! You may be rolling on a second take when suddenly outside the window the sun comes out and hits a white car parked across the street.

[gabj3]

In a technical sense –

Your camera analogue architecture (your photosite, column amps – and all the circuitry before digital quantization) is photographically linear and linear in signal.

In contrast, your photopic vision perceives light logarithmically. I.e. you perceive each photographic stop of light with an equal amount of value even though they are linearly double or half the amount of energy.

This is where the digital world of signal processing and your photopic vision do not align. Producing a camera’s analogue sensor architecture in anything other than a linear fashion would be problematic from a sampling and gain perspective.

However, for a camera to capture an additional stop of dynamic range, it must have double the internal latitude in quantization and a double physical saturation limit.

So yes, extending a camera’s dynamic range isn’t easy – especially in a fashion that works photographically.

[Author]

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