I am confused here. I thought the Log curves were designed to sacrifice detail in the highlights where the eye is less sensitive to small incremental light level changes and give more detail to the darker areas were smaller level shifts are more apparent. Also the log Transforms keep the signal from hard clipping on top and bottom
(Hence 10 bit is minimum, note that 10 bit can hold 4 times more info than 8 bit, per channel, so the total sum is way more.)
So, in theory this could be a good thing (If you have to shoot a really high contrast image and cannot filter / light). As others have pointed out, make sure the exposure is as 'hot' as possible to take as much advantage of the bandwidth (read, the numbers from 1 to 1024).
Then, in post, the process is reversed, so detail in both dark and light is preserved as good as possible, as the cost of less steps in color gradients.
Human perception and lineair / log are different things. Sometimes people perceive lineair (twice as heavy), sometimes log, (sound volume). But sound volume is NOT log always, as the human ear is also more perceptive for certain frequencies. (And when you age, you'll loose high frequencies.)
Sadly, in my real life tests it just does not work. (Well, it does, but the resulting image is never as pretty as a 'normal' shot, and it takes a shitload of time, so I fail to see the point.)
In my basic understanding of log math etc... things like vision or hearing are logarithmic in nature. The perceived volume change a person hears depends on the overall loudness to begin with. Doubling the power isn't twice as loud. Hence going from a one watt amp to a ten watt amp will seem much more different than going from a hundred watt amp to 110 watt amp. Same power jump but much less perceived difference in loudness/volume. I know there are technical differences these days between loudness and volume but that's not what I'm talking about here.
But sound frequency is normally lineair (But that is part education. In medieval times musical notes were different, so all medieval music nowadays sounds horrible out of tune…)
In psychology, there is a rule that people can notice the difference between two 'things' if the difference is bigger than 10%. That goes for color, weight, size, anything.
(Hence people have huge trouble sorting out Euro coins, as a lot of them are the same color and have less than 10% diameter / weight difference.)
Now that can be trained. Same as a grader sees more than an end user, a bartender/cabdriver has little problems sorting out the coins. (I still can't do it fast.)
And then there is the logic on how a source travels. A normal lamp shines 360 degrees in 3D. So, a bit further means that the energy emitted spans the surface of a globe. (Assuming there is no energy loss in the travelling of the waves.)
Same goes for 'some' sound sources. (A hammer on an anvil)
Surface of a sphere is 4
r2
r2So, at a distance of 1, the surface is 12.5
But at a distance of 2, the surface is 50.5
And at a distance of 10, the surface is 1256.6
Looks like log, doesn't it :-)
(There is a reason for spotlights with reflectors :-)
If you have a laser pointed at your source, the amount of illumination does not matter that much if you change the distance...
In broad strokes I remember being taught that things in nature tend to behave in a log manner because they are based on perception and not actual volts etc... that can be measured.
This is always a nice one: https://www.youtube.com/watch?v=vJG698U2Mvo
So did I get my memory backwards and it's really the bright lights where the human eye is most sensitive to brightness changes? I thought the log was just keeping the highlights from clipping hard like they would in a traditional sense too.
Oh my brain hurts.
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Posted by: Bouke <bouke@editb.nl>
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