Kolor-Pikker
Well-known member
This test was mainly to feed my curiosity, but I think it might be interesting to share the results here as well...
I've noticed before, when switching to -3 gain on the 370 that you lose a bit of highlight headroom compared to 0db gain, this pretty much made me believe that it was simply in-camera processing that darkened the image (as negative gain typically does on dSLRs)... or does it?
I loaded some test clips into Premiere today to figure out just how -3 gain works and found some pretty interesting results while looking at the YC monitor:
-3db gain
first frame after switch to 0db
0db gain
The moment you flick the gain switch, the highlights are expanded to a certain degree and then the whole image gradually becomes brighter, but visually nothing looks out of the ordinary (you get a teeny bit more detail in the highlights at -3db it seems).
Now the interesting part comes when we do some highlight recovery by applying a "Luma curve" adjustment to bring down the highlights:
-3db gain
first frame after switch to 0db
0db gain
Notice anything unusual? The first and third frame look just the way I would have expected them to, after all, you can't magically get more highlight detail when the camera is supposedly hitting it's limit and clipping... but it's not.
In the second frame, the highlight detail is very well preserved, but you'll never see it under normal circumstances because the camera decides it wants to brighten the image up after switching to 0db and blows out the highlight headroom it just got.
So this makes me wonder, just how much dynamic range is on hand here, but is being limited by processing? Could there be the possibility of in-camera adjustment that doesn't compress the highlights this way? If Panasonic has some secret firmware that lets you record the linear gamma coming right off the sensor; I'd sure love to test it!
I've noticed before, when switching to -3 gain on the 370 that you lose a bit of highlight headroom compared to 0db gain, this pretty much made me believe that it was simply in-camera processing that darkened the image (as negative gain typically does on dSLRs)... or does it?
I loaded some test clips into Premiere today to figure out just how -3 gain works and found some pretty interesting results while looking at the YC monitor:
-3db gain
first frame after switch to 0db
0db gain
The moment you flick the gain switch, the highlights are expanded to a certain degree and then the whole image gradually becomes brighter, but visually nothing looks out of the ordinary (you get a teeny bit more detail in the highlights at -3db it seems).
Now the interesting part comes when we do some highlight recovery by applying a "Luma curve" adjustment to bring down the highlights:
-3db gain
first frame after switch to 0db
0db gain
Notice anything unusual? The first and third frame look just the way I would have expected them to, after all, you can't magically get more highlight detail when the camera is supposedly hitting it's limit and clipping... but it's not.
In the second frame, the highlight detail is very well preserved, but you'll never see it under normal circumstances because the camera decides it wants to brighten the image up after switching to 0db and blows out the highlight headroom it just got.
So this makes me wonder, just how much dynamic range is on hand here, but is being limited by processing? Could there be the possibility of in-camera adjustment that doesn't compress the highlights this way? If Panasonic has some secret firmware that lets you record the linear gamma coming right off the sensor; I'd sure love to test it!