Dlog vs Dlog-M vs HLG

Lifeofmikey

can someone tell me the difference between these 3? especially dlog and dlog m

DJI Paladin

Hi there. Thank you for reaching out. You may refer to the information below:

D-Log M: D-Log M allows the camera sensor to record enough dynamic range. As the photo has been processed, it leaves less room for grading in post-production compared with D-Log, but you can more easily color grade during post-processing.

D-Log: D-Log allows the camera sensor to pull as much dynamic information from the scene, get the maximum dynamic range compared with other color modes, and give you more flexibility in your post-production as the photo is not processed. But it will devote more time to post-processing as LUTs should be used to color grade D-Log footage before post-processing. For more details, refer to D-Log D-Gamut Whitepaper.

HLG: HDR videos of the Mavic 3 Pro fall within the HLG video standard.

MS

Also be aware of the different file sizes each of them create.
It's best to do a DIY test by recording of a minute each, during a hover of the same scene.

And the ISO's available differ.

Geo_Drone

DLOG have the biggest DR, 10 bit. Still, DLOG is less than LOG, as we talk at DJI about Limited RGB DLOG, so DR from Mavic 3 will always be lower than LOG from Autel Evo2Pro for example.

DLOG-M is DLOG without balls, as DR is less, 10 bit (is closer to Normal profile). You can still edit it well, as you have 10bit and will not see banding.

Normal is 8 bit and can be moderately edited as you are constrained by color banding. Is good for fast works or lazy persons.

flojo

Geo_Drone Posted at 5-31 03:52
DLOG have the biggest DR, 10 bit. Still, DLOG is less than LOG, as we talk at DJI about Limited RGB DLOG, so DR from Mavic 3 will always be lower than LOG from Autel Evo2Pro for example.

DLOG-M is DLOG without balls, as DR is less, 10 bit (is closer to Normal profile). You can still edit it well, as you have 10bit and will not see banding.

I hope you do not curse me, If I make a little correction/addition:

Normal is 8 Bit 4:2:0 color on the Mavic 3 Pro, however on the Mavic 3 Pro Cine when recording in ProRes (all three) you get 10 Bit 4:2:2. But, you would not buy the Cine and then go for the normal profile. I think most Cine pilots use D-LOG, for the 3x D-Log M (because this is sadly the only "Log" option we have right now) and sadly the 7x is only available in normal color profile at the moment. So for this lens, the Cine could be better. But that is a lot of money only to have a better color profile for one lens (which is the least best of all three).

Geo_Drone

flojo Posted at 5-31 05:39
I hope you do not curse me, If I make a little correction/addition:

Normal is 8 Bit 4:2:0 color on the Mavic 3 Pro, however on the Mavic 3 Pro Cine when recording in ProRes (all three) you get 10 Bit 4:2:2. But, you would not buy the Cine and then go for the normal profile. I think most Cine pilots use D-LOG, for the 3x D-Log M (because this is sadly the only "Log" option we have right now) and sadly the 7x is only available in normal color profile at the moment. So for this lens, the Cine could be better. But that is a lot of money only to have a better color profile for one lens (which is the least best of all three).

Sure, I am happy to see added info to explanations.

Of course, in order to get ProRes and invest so much in Cine version I do not know if is justified, as you also stick with an SSD (another stupidity from DJI, I would always prefer a V90 card instead of SSD, as if is gone, you loose all data, and connecting it to save a ProRes file between works is not possible as takes a lot of time because of huge format).

But is all about people choices...and each one will choose as it considers.

GregL2570

For anyone using a DaVinci Resolve Studio Color Managed Workflow with DJI Mavic 3 Pro Cine clips, here are a few tips: I went out and did some testing this weekend, using the Mavic 3 Pro Cine through series of waypoints in order to record 3 identical passes of the same scene, for the same length of time and with the exact same settings, (with the exception that each pass was recorded using a different color space profile). HLG, D-LOG, and D-LOG M. All ProRes422HQ 4K/60fps.

All three clips were exactly 45 seconds in duration. Only the HLG file contains a truly wide dynamic range input color space (BT.2020 HLG). Both the D-Log and D-Log M files contain HD (1-1-1) input color spaces, which, despite the appearance of a flat, low contrast, log gamma profile, are actually both recognized as Rec709 input color spaces.

Since only the wide angle lens on the Mavic 3 Pro Cine can record in full D-Log, (the other two lenses can only use D-Log M), this means you either have to work with mixed color profiles when switching between lenses, or you can choose to record D-Log M across all three for more consistency. Or, you can choose HLG ProRes422HQ across all three lenses and get output files that not only contain slightly more data in terms of actual file size, but also contain a BT.2020 HLG wide dynamic range input color space which works perfectly seamless in a DaVinci Resolve Studio Color Managed Workflow. There's no need to apply any LUTs, nor any need to create Color Space Transforms for the input and output stages (as required when using D-Log and/or D-Log M profiles). Even though the final output files do not have the initial appearance of log gamma assets, the resulting files actually contain slightly more data than the log files and still provide an incredibly wide dynamic range of flexibility for color grading while in the intermediate editing stages prior to final output.

I hope this information is helpful. From here on out, I'm definitely going to be recording all DJI Mavic 3 content using the HLG profile instead of either Log option for the obvious reasons listed above.

skyscope

GregL2570 Posted at 5-27 09:59
Only the HLG file contains a truly wide dynamic range input color space (BT.2020 HLG). Both the D-Log and D-Log M files contain HD (1-1-1) input color spaces, which, despite the appearance of a flat, low contrast, log gamma profile, are actually both recognized as Rec709 input color spaces.

You shouldn't focus too much on the clip-metadata, the infomation is in the streams. When it comes to color space, DLog's is much larger than HLG's (D-Gamut vs. Rec.2100/2020). Also, regarding the gamma curve, DLog offers significantly more dynamic range.

DLog is the common denominator with the Mavic 3, for example, you can easily create HLG (or PQ, HDR10, DolbyVision) from DLog, but not the other way around. Besides, HLG isn't really suited for post-production work because it has a linear gamma up to about 60%, and only above that does it have a logarithmic transfer (hence the name Hybrid Log Gamma).
This makes it very hard, if not impossible, to grade consistently across different shots with different exposure. HLG is really a delivery format, and you should only use it for recording if you plan to play it back exactly as it is in a HDR Pipeline. In a SDR Pipeline you wil get in a lot of trouble with grading HLG.

In the end, as I said, it contains less information than DLog, both in terms of color space and dynamic range. Take a look in the DLog/D-Gamut Whitepaper from DJI, but you can check this all out for yourself using the right HDR color workflow and settings and for example the CIE plot in DaVinci Resolve.