I found something interesting on this. Here’s DJI’s white paper on D-Gamut and D-Log.
It’s saying that lower than EI 1600 the output signal will not reach 100% but EI 1600 and above you CAN reach 100% and above.
Basically at EI 800 and below you are sacrificing some dynamic range for lower noise but at EI 1600 and above you will get higher noise for more dynamic range. A similar situation I can think of is Sony’s HLG1, HLG2, and HLG3 profiles. HLG1 is low noise but lower dynamic range, HLG3 is the most dynamic range but you get the most noise, and HLG2 is somewhere in the middle all while set to the same ISO settings.
This would explain why the rec 709 was less noisy but had less dynamic range and why the DLOG was more noisy and why the noise didn’t go away when you brought it back down in post. So the EI you pick isn’t really fully reversible in post.
It’s saying that lower than EI 1600 the output signal will not reach 100% but EI 1600 and above you CAN reach 100% and above.
Basically at EI 800 and below you are sacrificing some dynamic range for lower noise but at EI 1600 and above you will get higher noise for more dynamic range. A similar situation I can think of is Sony’s HLG1, HLG2, and HLG3 profiles. HLG1 is low noise but lower dynamic range, HLG3 is the most dynamic range but you get the most noise, and HLG2 is somewhere in the middle all while set to the same ISO settings.
This would explain why the rec 709 was less noisy but had less dynamic range and why the DLOG was more noisy and why the noise didn’t go away when you brought it back down in post. So the EI you pick isn’t really fully reversible in post.
