Question
When processing sound, one can use a Compressor to reduce the dynamic (DR) range of the signal. In photography, we often run into the problem of scenes with DR larger than the sensor's capture ability. For example, shooting a person on a white snow background. This leads to either the subject is underexposed, the snow is overexposed or both.
A Neutral Density filter is used to reduce the amount of light received by the sensor. However, a uniform filter does not (theoretically) reduce scene DR. Graduated ND filter can be helpful in some cases, but the use is very specific.
Is there a device (material) that can reduce the received DR? Preferably, a passive device (like a lens filter)?
Obviously, in the sound compressor example above, the DR of the signal chain has to be able to accommodate the original DR in order to prevent unwanted clipping and distortion. In Digital Photography, this is equivalent to a high DR sensor, and the compression itself is equivalent to HDR tone mapping.
Answer
Tiffen ultra contast filters were developed for this. Look it up; they got an Oscar for it. (My bad, wrote Low contrast. Edited)
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