Long exposure of waterflow, to process or not to process


(Filip) #1

This is how not to do it story. There are two shots, one is 1/4 and another 2 seconds. Here are exported and resized jpegs:

1/4 no processing

ignore people at top of frame. Rain, cold and they must come and examine water at close distance.

2 seconds processed with dehazing, equalizer and local contrast

the same 2 seconds without processing

My processing effort ruined long exposure and milky water, about 4 stops. Maybe 5 or more stops. 1903 is 100 ISO and 1922 is Lo 1 (50 ISO), both are taken through variable ND filter some mid value, do not remember exactly.

Sidecar for processed 2 second shot FED_1922_01.NEF.xmp (2.5 KB)

Released under CC BY-SA 4.0, enjoy


Without processing you see more of the time-smoothed water. With the processing you’ve gotten more of the underlying rocky structures beneath the water, which to me is more natural looking.

(Filip) #3

Whole long exposure (I see that as goal of this exercise) is lost and it is still not natural, exposure of human eye is 1/100 to 1/200 of second. For example 1/15 will also produce smoothing effect but you can not see that with naked eye.


Well I was speaking more of how natural the stream looks, not comparing with the naked eye. Never heard of 1/100 - 1/200 for eyesight…

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and a dark adapted retina can be as sensitive as a 2s exposure. For motion, the persistence of vision is 1/16…