D-Log vs D-Cinelike Video Noise

[baddog]

So I've recently started taking the time to learn about D-Log, color correction, grading, etc. I thought I had found that I liked D-Log the best with a custom LUT and some minor additional tweaks from me. However this weekend I did some shooting in D-Cinelike to compare. From a color perspective, either could work just fine for me, but what I've found is that D-Log seems to have significantly more noise (sharpness at +1 or even 0) than D-Cinelike. Has anyone else experienced this? I would normally suspect ISO settings, subject brightness, etc. to be the culprit, but I'm shooting in daylight in bright sunlight. I should have very little ISO noise - and in fact I don't in D-Cinelike. Is this expected with D-Log? Is the in-cam noise reduction algorithm different for different video modes?

FWIW, this is an older (March 2017) Mavic Pro refurb that I got from DJI Refresh. Other than the fact that it won't do 1080p/60 in a usable fashion and now this, I've been completely happy with it. It's running the latest firmware, and I'm using the latest version of DJI Go. I've been shooting in auto to start, but plan to experiment with manual settings to see if it's jacking up my ISO settings for some reason.

LP

I have always used D-cinelike and ND filters to keep ISO and frame rate down to normal levels. I have never really had any noise issues

 

[Brojon]

Exactly - for the record, I'm already using ND filters, but if it was ISO noise caused by the cam selecting a higher ISO in auto, you'd expect ND filters to make it worse, not better. On bright sunny days, there's no reason the cam shouldn't be selecting an ISO of 100. That said, I do really wish these videos stored EXIF-like info so I could go back and check. I've now tried this on two separate days with the same results - ie: put the MP in the air and point it at a scene and let it sit. Then record some in D'Log, then switch to D-Cinelike and record again. Same style settings, same lighting conditions, same subject. D-Log has more noise.

I've now found some settings with D-Cinelike that I'm happy with, so that's my solution for now. I'm open to any other suggestions or thoughts.

LP

Seems I remember that D-log puts it in ISO 400 regardless for some stupid reason.
I use Cinelike since D-log really isn't log anyway...

 

[Cliff_622]

Seems I remember that D-log puts it in ISO 400 regardless for some stupid reason.
I use Cinelike since D-log really isn't log anyway...

Nah,...forcing 400 ISO is perfectly normal in the log world. This minimum ISO is a "pre-amp" that is used to amplify the signal so it can be curved properly. All camera that do log do this. Sony A7S-II = 1600 ISO, Sony FS5-2000 ISO, Lumix GH5 = 400 ISO. Some other Sony cameras use 800 ISO too. This is necessary to collect enough signal to "bend" or "compress" it into a log curve for recording.

 

[Brojon]

Nah,...forcing 400 ISO is perfectly normal in the log world. This minimum ISO is a "pre-amp" that is used to amplify the signal so it can be curved properly. All camera that do log do this. Sony A7S-II = 1600 ISO, Sony FS5-2000 ISO, Lumix GH5 = 400 ISO. Some other Sony cameras use 800 ISO too. This is necessary to collect enough signal to "bend" or "compress" it into a log curve for recording.

So basically you're saying I'm right. The OP was asking about noisier images using D-Log. Facts are that ISO 400 is significantly noisier than ISO 100 - especially on these smaller sensors. Easy enough to verify empirically.

 

[Cliff_622]

Yes, you are right. All log gamma curves for all cameras on Earth are noisier than rec709 or "standard" contrast gammas. The reason why is that log gamma curves dive deeper into the sensor's output. They go down "further" into what the sensor can see. They read the noise floor that standard profiles cut off. So yes, log is only guilty of capturing all of the sensor's output, even the dirty bottom. this is why you see further into the shadows in log. It's up to you to crush those blacks back down in post and use noise reduction.

 

[Brojon]

Yes, you are right. All log gamma curves for all cameras on Earth are noisier than rec709 or "standard" contrast gammas. The reason why is that log gamma curves dive deeper into the sensor's output. They go down "further" into what the sensor can see. They read the noise floor that standard profiles cut off. So yes, log is only guilty of capturing all of the sensor's output, even the dirty bottom. this is why you see further into the shadows in log. It's up to you to crush those blacks back down in post and use noise reduction.

Well you make it sound so *clean* lol.
Truth is that noise gets boosted and compressed to be at the same level as your middle grays. This actually makes shoving the shadows back harder since the "distance" has been compressed and is very narrow. That's why a poor grading results in a contrasty image. It also makes noise reduction a given meaning you *will* lose some image quality How much depends on how aggressive the algorithm. If you shoot under by a half stop or more you're really going to have issues with shadows and noise since you've effectively reduced you DR by that much.
It's a finicky business with these limited sensors - anyway, that's why I prefer Cinelike since it avoids the added ISO noise. Incidentally increasing the ISO over "native" also reduces DR a bit since the sensor response is non-linear. That's why really high ISO night shots have muddy and blocked up shadows.

 

[Cliff_622]

Well you make it sound so *clean* lol.
Truth is that noise gets boosted and compressed to be at the same level as your middle grays. This actually makes shoving the shadows back harder since the "distance" has been compressed and is very narrow. That's why a poor grading results in a contrasty image. It also makes noise reduction a given meaning you *will* lose some image quality How much depends on how aggressive the algorithm. If you shoot under by a half stop or more you're really going to have issues with shadows and noise since you've effectively reduced you DR by that much.
It's a finicky business with these limited sensors - anyway, that's why I prefer Cinelike since it avoids the added ISO noise. Incidentally increasing the ISO over "native" also reduces DR a bit since the sensor response is non-linear. That's why really high ISO night shots have muddy and blocked up shadows.

You are 100% correct. To be completely honest, DJI has no business putting a severly flat log gamma curve on a Mavic Pro with a tiny 1/2.3 sensor with a horrible Ambarella A9 dinosaur video processor using a terrible 60Mbp/s CODEC with only 8bit sampling. I mean, you literally could not pick a worse case scenerio!

D-Cine is the way to go. If you drop the contrast to -1 or even -2, this will already give you all the USABLE dynamic range this sensor can muster.

DJI needs to build a better log curve! They need to copy Sony SLog-2 that maps the sensor's max white clip to 109IRE and its bottom black to 0 IRE. This will use the FULL 8bit values of 0-255. Today, their DLog tops out at 80 IRE and bottoms out at arround 10-15 IRE. What dummy at DJI thought that was a good output mapping? Its only using 6-7 bits of the 8bits that are available!

 

[LeafPeeper]

What's weird then is that the cam actually says the ISO is at 100....found that kind of odd if it is actually getting boosted.

LP

 

[Pingman68]

I have always used D-cinelike and ND filters to keep ISO and frame rate down to normal levels. I have never really had any noise issues

Same here. In most of the videos I make the drone footage is supplemental to what I shoot with Filmic Pro on my phone. The D-cinelike profile matches up well with the flat profile I use on it.

 

[LeafPeeper]

So from all this discussion (and other threads), I now have a pretty good idea of what D-Log is. What exactly then, is D-Cinelike? I just did a bunch of comparison videos with D-Cinelike vs None, and I think I still like D-Cinelike better after post processing.

LP

 

[Pingman68]

So from all this discussion (and other threads), I now have a pretty good idea of what D-Log is. What exactly then, is D-Cinelike? I just did a bunch of comparison videos with D-Cinelike vs None, and I think I still like D-Cinelike better after post processing.

LP

From my understanding, D-Log is a more aggressive profile than D-Cinelike. Which on the smaller sensors like the Mavic and phones, might be pushing their abilities to capture dynamic range a bit too much. I’m relatively new to videography, and I’m sure someone with more experience might be able to capture their footage a little bit better. They may also have more knowledge of post editing techniques, and can squeeze more out of the Mavic’s sensor with D-Log, but for me D-Cinelike is a happy median.

 

[LeafPeeper]

So D-Cinelike is still attempting to capture a wider dynamic range than say TrueColor, Vivid or None? I'm still finding D-Cinelike easier to process to get the kinds of color and contrast I want, where as it's nowhere near as easy with 'None'. In particular, I seem to get more detail in the shadows with D-Cinelike....is that expected like with D-Log?

LP

 

[Pingman68]

So D-Cinelike is still attempting to capture a wider dynamic range than say TrueColor, Vivid or None? I'm still finding D-Cinelike easier to process to get the kinds of color and contrast I want, where as it's nowhere near as easy with 'None'. In particular, I seem to get more detail in the shadows with D-Cinelike....is that expected like with D-Log?

LP

That is more or less my understanding, but like I said I’m somewhat new to this, so I may not have the best grasp of it.

 

[CodeCutter]

Thanks LeafPepper for starting this thread and the subject matter experts spreading light on the subject. I started using d-log and color correction when a firmware upgrade started over exposing highlights on None setting. Like LeafPepper I could not get the noise out of D-log until I started using Neat denoise plugin and a preset denoise profile created by the Film Poets and Neat. This works really well and the footage looks great. But it can take 10 hours to export a 15 minute 4K video. I now use d-cinelike 90% of the time and d-log in high contrast scenarios like sunrise and sunsets.

 

[bushie]

Been following this thread with interest.

I started videography in my teens, am now 73.

Started with a clockwork 8mm camera that used 16mm film. Took a strip of video 8mm wide, turn film over and another 8mm strip. Processing included splitting the fim down the centre. Moved on to super 8mm film, and then mini DV tape and finally to digital on a card. Recently started using a Mavic pro. I find myself mixing clips from the DV and the MP at times.

First with the tape and then the digital I used Premier pro. Recently upgraded to a more powerful PC and am on the learning curve with DaVinci Resolve.Great step after editing by cutting and glueing film!

I have had problems following a lot of the discussion in this thread on D-Log. Can anyone suggest a good book or maybe a link that will spell it all out in simple terms? I Have tried a number of U Tube videos but they all assume a basic knowledge that I don't have.

Also suggestions on LUTs for D-Log and D-Cinelike for DV would be appreciated.