DLOG - Does it make any difference?

[ianwood]

I've never had much faith in DLOG. But I don't have much experience with it as my go to DJI platform is the Inspire 2 and I can shoot RAW in CinemaDNG which is far more powerful than any LOG curve. While I wish the Mavic 3 Cine could record CinemaDNG, I am OK with ProRes but it means I need to re-evaluate DLOG to see if DJI has made it any better over the years. My conclusion is it is still no good. Here are some observations:

1. DLOG shifts colors into strange places which are really difficult to correct. There is an overall green shift.
2. DLOG grade is less natural feeling. The sky in particular feels less dynamic.
3. DLOG gives your exposure A LOT of room at both ends when filming. Something like 2-3 stops. Which seems absurd. Maybe this is its big benefit if you can't nail your exposure.
4. DLOG I don't see any noticeable increase in latitude.
5. Rec.709 does have minor clipping even if you nail the exposure in high-contrast shots but it's minimal most of the time. Cut contrast by 15% and reel in the highlights and you should be OK.
6. ETTR sucks in both versions for highlight recovery. I don't look at my exposure value often when filming but it is usually between -0.7 and -1.0. I'd rather kill a shadow than have glaring highlights I cannot tame.

I recently shot some footage in both "standard" rec709 and DLOG to compare. I shot at midday to get some high contrast "difficult" footage. Both processed in Premiere Pro. The DLOG footage uses the DJI D-LOG to Rec.709 V1 LUT. No color correction but lightly graded to smooth out highlights and shadows. Shot at 5600K.

Here are some still frames to compare.




And then desaturated which I find easier to evaluate the overall grade and looking for loss of detail in shadows / highlights. Again I don't see any benefit in the DLOG. Midtones are brighter in 709. You can still see the sky is more flat in the DLOG. DLOG does hold a little more detail in the shadows but it's not that much.

 

[sar104]

The most obvious difference that I see there is that the 709 is much noisier than the DLOG - most noticeably in the sky.

 

[ianwood]

The most obvious difference that I see there is that the 709 is much noisier than the DLOG - most noticeably in the sky.

True. Failed to mention that. Noise doesn't bother me all that much until I have to shoot at night which I will never do with a Mavic 3.

What is interesting about that is both were shot with exactly the same settings, ISO, etc.

 

[Saladshooter]

If you shoot enough skies with the Normal / Rec.709 you will see some banding. DLOG being 10 bit avoids this by having a billion colors available or roughly 60 times the available shades of DJI Normal. Even though many screens can't truly use 10 bit color at the moment, using it future proofs your footage and will look smoother after processing. ProRes being natively 10 bit, sidesteps this problem but is hard to use for professional work on the Mavic 3 because of the lack of removable storage.

DLOG is a bit tricky to work with. I get better results on my own than using the DJI LUT. DLOG is also so flat that it takes lots of work to bring it to life. That is why the promised but missing HLG / HDR 10 bit format for the Mavic 3 is important. It comes out of camera closer to a finished product and retains the ability to work the footage toward your intended look. HLG will be a lot easier for many people to use.

Coming from your Inspire to the Mavic 3, I don't think you will ever be truly satisfied with the dynamic range and ability to rework your product.

 

[RealSting]

Personally I don’t use LUTs because they bake in certain colour parameters the user cannot change - sure, you can change the overall grade but the LUT is only doing what’s it’s been told by it’s creator if you see my meaning?! I’ve always got better results making the adjustments myself - which is why I’ve invested an awful lot of time and some money in learning how to grade properly.

If we want to continue this point, DaVinci resolve has the COLOUR advantage over Premiere, you may (with learning) get better overall results.

 

[Ralph thompson]

Colour correction & grading is a learned skill, if yr not educated in colour adjustments then you should take some courses to get the full advantage of raw log data. As RealSting says applying LUTS will most likely do permanent damage to the image (LUTS usually pixelize the data most likely losing all the hidden texture in highlights and detail in shadows) and theres an optimum order in which to apply the différant adjustments. Go to DaVinci Resolve Training for excellent free videos on color correction and grading. 10 bit color depth & dlog allow for better color & smoother gradient.

 

[Eagle Eye 62]

I have had similar frustration with Dlog and will not use it anymore. I would love to see HLG in the next update but I am not holding my breath. For now I am pretty happy using standard mode and making subtle color corrections (I find this is more necessary on cloudy days than in bright sunshine)

 

[ianwood]

Personally I don’t use LUTs because they bake in certain colour parameters the user cannot change - sure, you can change the overall grade but the LUT is only doing what’s it’s been told by it’s creator if you see my meaning?! I’ve always got better results making the adjustments myself - which is why I’ve invested an awful lot of time and some money in learning how to grade properly.

If we want to continue this point, DaVinci resolve has the COLOUR advantage over Premiere, you may (with learning) get better overall results.

I 100% agree with you on LUTS. But D-LOG is so desaturated, un-contrasted, etc., it is a lot of work to bring out the long way. I suppose I could try but at this point I am not seeing any advantage to DLOG in gained latitude so I am not sure it's even worth the effort to evaluate further.

I am less proficient with Resolve but do use it for my RED IPP2 color grading process.

 

[ianwood]

If you shoot enough skies with the Normal / Rec.709 you will see some banding. DLOG being 10 bit avoids this by having a billion colors available or roughly 60 times the available shades of DJI Normal. Even though many screens can't truly use 10 bit color at the moment, using it future proofs your footage and will look smoother after processing. ProRes being natively 10 bit, sidesteps this problem but is hard to use for professional work on the Mavic 3 because of the lack of removable storage.

DLOG is a bit tricky to work with. I get better results on my own than using the DJI LUT. DLOG is also so flat that it takes lots of work to bring it to life. That is why the promised but missing HLG / HDR 10 bit format for the Mavic 3 is important. It comes out of camera closer to a finished product and retains the ability to work the footage toward your intended look. HLG will be a lot easier for many people to use.

Coming from your Inspire to the Mavic 3, I don't think you will ever be truly satisfied with the dynamic range and ability to rework your product.

No issues with banding so far but I am shooting in ProRes 422HQ with the cine version of the Mavic which may be helping in that respect. I am not seeing any extra detail or less banding in the DLOG footage at this point. As was pointed out before there is more noise in the rec.709 color profile at the same ISO (which is odd) but that's not a huge concern at this point.

The only advantage I am seeing at this point is for people who have a hard time getting their exposure correct when filming. Don't need that.

I am grading on calibrated monitors. Retina iMac (P3 gamut) but also a calibrated monitor using a BlackMagic Decklink SDI output. All my grading is to achieve a rec.709 output with correct gamma so that it can be cut into footage from far better camera systems and workflows by editors and colorists.

 

[sar104]

I 100% agree with you on LUTS. But D-LOG is so desaturated, un-contrasted, etc., it is a lot of work to bring out the long way. I suppose I could try but at this point I am not seeing any advantage to DLOG in gained latitude so I am not sure it's even worth the effort to evaluate further.

I am less proficient with Resolve but do use it for my RED IPP2 color grading process.

DLOG definitely needs robust grading, but I found that once I had an idea of what was needed in Resolve (courtesy of a few instructional YT videos) the results were very good.

 

[ianwood]

I graded a DLOG clip manually. Pretty easy. Didn't mess too much with the contrast or saturation. The color shifts are even more pronounced so it's not the LUT that's causing them. More likely the LUT tries to correct for some color shifts that are inherent in the DLOG. This could simply be non-linear output from the sensor that gets more complicated when you apply a curve. Just a guess.





EDIT: Here's a side by side view to make it more obvious.

 

[Serio]

I graded a DLOG clip manually. Pretty easy. Didn't mess too much with the contrast or saturation. The color shifts are even more pronounced so it's not the LUT that's causing them. More likely the LUT tries to correct for some color shifts that are inherent in the DLOG. This could simply be non-linear output from the sensor that gets more complicated when you apply a curve. Just a guess.



View attachment 145923

EDIT: Here's a side by side view to make it more obvious.

View attachment 145926

The Rec.709 is easily the best colour of those three IMO. I've reverted to shooting Normal rather than D-Log on my M3 but there are other trade-offs. The colour accuracy in M3 D-Log is an issue and no LUT or method I've tried has been able to reliably fix it. It's very frustrating.

 

[Ralph thompson]

DLog has small benefits if you are trained & knowledgable in colour correction and grading. LUTs are destructive and in my opinion, its a waste of time using DLog if you're just going to destroy the benefits with a LUT. Manual adjustments are by far the best approach, you must first recover the hidden detail, pull back all the highlights and rescue the shadows, then establish neutral points, then correct colour; it does require time, skill and patience.

 

[ianwood]

DLog has small benefits if you are trained & knowledgable in colour correction and grading.

In theory, yes. In practice, not so much.

 

[Serio]

DLog has small benefits if you are trained & knowledgable in colour correction and grading. LUTs are destructive and in my opinion, its a waste of time using DLog if you're just going to destroy the benefits with a LUT. Manual adjustments are by far the best approach, you must first recover the hidden detail, pull back all the highlights and rescue the shadows, then establish neutral points, then correct colour; it does require time, skill and patience.

I actually use a colour space transform instead of a LUT typically. Both a CST in Resolve and the official DJI LUT get more or less the same result for me.

I'd love to send someone a particular D-Log Mavic 3 clip and see if they could get it right. I'm convinced DJI are doctoring the greens. Unfortunately, I didn't film the same scene in Normal so I only have edited photos of the scene to compare.

Edit: I've gone back to said problematic clip and for the first time managed to actually get results that I'm happy with. Key seems to be bumping the saturation for everything but the greens. I'd previously tried to combat this pushing tint to magenta, but that's often risky. Resolve curve below. Plus a bit more saturation in general.



Then dropping luminance for blues especially to fix skies.

 

[ianwood]

I'm convinced DJI are doctoring the greens.

Agreed. There's definitely something happening in the greens that is hard to fix. It could be how the sensor works at different luminance levels but I've seen similar issues with DLOG across DJI products that I think it's simply another poor implementation.

Getting DLOG back to a decent rec709 curve is easy. Fixing the color shifts is not easy. And I still don't see any significant improvement in detail.

I wish DJI would hire / poach some of the color experts from Panasonic or Sony. They're using the same sensors.