I have been looking at some other picture profiles claiming to offer a log style curve or the maximum dynamic range from the camera. One in particular caught my eye as the creator advocates the use of a very high black level setting. Normally the black level setting does nothing more than set the zero reference point (called the pedestal) for the black level, it does not normally affect dynamic range. So I decided to investigate the claim that a high black level on a FS700 improves shadow performance, at the same time coming up with my own settings for maximum dynamic range.
To establish whether the black level setting made any difference to the dynamic range I performed a very simple test using a greyscale chart and a waveform monitor. I exposed the grey scale so that one of the mid scale grey bars was just fractionally below the zero, black level on the waveform monitor. Now, IF the black level is changing the dynamic range, then raising the black level should allow me to bring that now just invisible grey scale bar back up above the black level so that I can see it on the waveform monitor as a discreet bar. Well, it didn’t. The overall black level comes up as expected, but the grey bar does not make an appearance, it stays firmly below the black level. This proves that the black level control is actually working as expected, i.e. just changing the zero point. Now you can decrease the dynamic range by using a high negative value as this will push dark parts of the scene into clipping, but raising the level does nothing more than raising the black pedestal level. Raising the pedestal level may make the image look flatter on a monitor because it will look greyer due to blacks that no longer look black on the monitor, but the dynamic range is not in fact being increased and your wasting recording data.
The next thing to look at is the Black Gamma setting. Now as this is a gain setting (as opposed to just a level setting) I did expect to see some changes in dynamic range. What’s interesting with this setting is that it operates over 3 ranges, low, mid and high. High range operates over the greatest range, but has the least effect on deep shadows. Low Range has the greatest effect on deep shadows and by using Low Range and the maximum +7 level setting I was able to gain almost a half stop increase in low end dynamic range. +7 with the High range setting made almost no difference to the darkest parts of the image. From previous testing and experimentation I know that cinegamma 4 offers the greatest dynamic range, so by combining Cinegamma 4 with black gamma, low range at +7, I believe you are getting the absolute maximum dynamic range from the camera. You should note that set like this the camera records to 109%.
I have created a complete flat look, maximum dynamic range picture profile for the FS700 and you can find the settings by clicking here.