I have done some further research on the picture profiles and found out quite a bit of information.
In this post I will focus on the luminance and black gamma.
Luminance
Luminance determines the range of black and white that are in the footage. People familiar with the Panasonic GH4 will know that you can set luminance fundamentally in two ranges: 0-255 and 16-235.
What this means that you have in the first case 256 grades of grey and the in the second 220. Some people confuse luminance with dynamic range but they are not the same thing.
You will somewhere find the definition of limited for 16-235 and full for 0-255 this is what it means.
In particular video broadcasting legal luminance is 16-235 so if you use a clip produced at 0-255 the extremes will be clipped this is anyway resolved as the levels are mediated when clips are produced for compatibility.
On the other hand if you use a clip with range 16-235 on a computer that has 0-255 luminance range it will look as lacking deep blacks or whites.
Ultimately you need to decide what is that you are shooting for and if your clips are going to be played on a computer that works in RGB or on a Tv that has YUV.
Profile Name | Description | Luminance Range | Dynamic Range |
PP1 | Movie | 0-255 | < 7 stops |
PP2 | Still | 0-255 | < 7 stops |
PP3 | Video Natural | 0-255 | 7 stops |
PP4 | Video Vivid | 0-255 | 7 stops |
PP5 | Cine1 109% | 0-255 | 10 stops |
PP6 | Cine2 100% | 16-235 | 10 stops |
PP7 | S-log | 0-255 | 13 stops |
So the only profile that is broadcast compatible before editing is PP6 or the Cine2 gamma curve.
You can see that the dynamic range is the same for PP5 and PP6 so the fact that the camera records more grey levels does not really change things as the cine2 curve is smoother so it can accept higher input signals.
Black Gamma
In order to increase depth of blacks it is possible to use the black gamma setting. This has 2 controls, one is the Range Narrow, Medium, Wide and the other is the level that goes from -7 to +7
If you are going to grade your footage of and if you are going to use the video gammas PP1-PP4 you should not touch the black gammas otherwise you risk crushing the blacks.
However if you intend to use the cine profiles straight out of the camera you can tweak the black gammas accordingly.
The range determines where the setting will be effective.
Broadly speaking Narrow works on the first 10% of the signal, medium around 20% and wide around 30-35%.
What it means is that Narrow really works on the deeper blacks as you move to Wide you are altering also the grey and effectively changing the balance of the whole image.
More details here http://helpguide.sony.net/di/pp/v1/en/contents/TP0000909110.html
For what concerns the level a positive value will move black towards grey and a negative value shift grey towards black.
There are two main uses of the black gamma: get deeper blacks without altering the overall contrast this is obtained using the Narrow setting and a value between -3 and -7 or use the Wide setting with negative values to give the whole image a darker tone.
A setting of Wide with level around -3 gives an overall darker tone to a Cinegamma if you don’t want to change the blacks in post and remains overall balanced.
Which leads to my current favorite profile that is a customised PP6 setting the parameters that I have changed are:
I have tested the various Gamma with backlight situation and I found that Cinema2 performs best on my Tv where I watch my clips.
I prefer Cine2 even on the computer to be frank but it is true that the blacks are a bit light.
Color mode: I have tried Cinema and Pro am now on Pro with Saturation +8
Black Gamma: Range Wide Level -7 as the cine2 mode is quite dull I like to push the blacks a little overall.
As the Sony RX100 Mark IV records at 8 bit my opinion is that using S-gamut is not worth without an external recorder. And to be honest the amount of grading possible is quite limited so my approach is to get the video as good as possible out of the camera.
This is a little test with my Kitten