Color adjustment for the Mavic 2 Pro HLG?

[TomSull]

Hi, first, I'm a brand new pilot having just gotten my Mavic 2 Pro a couple of weeks ago, and I'm greatly enjoying it. I've gotten DaVinci Resolve 16 for color correction, and started shooting in D-LOG using the DJI D-Log to Rec.709 LUT.
I then tried HLG and saw a bit more color saturation in the raw images, so I thought I'd go looking for LUTs for HLG imaging with the Mavic 2 Pro. HLG looks like an interesting technology for color encoding so I thought I'd play around with it to see how it looks.

I found the Aerial Guide Mavic 2 Pro LUTs and I saw they have an HLG LUT so I purchased the set and tried it against a quicky HLG test video I did. Note that this is previous footage so I didn't set the recommended Sharpness and Contrast settings in the Mavic 2 camera, so they're at defaults.

The images below show the original HLG file at the bottom center, a D-Log image adjusted with the D-Log to Rec.709 reference LUT (as a reference for comparison to HLG) at the right, the Aerial Guide Mavic 2 Pro H.265 HLG True LUT to the right, and at top center, the HLG image color corrected with the D-Log to Rec.7.0 reference LUT.

To my eye, the best match to the D-LOG reference image is to use the SAME DJI D-Log to Rec.709 LUT on HLG as well as D-Log. The Aerial Guide LUT lacks saturation and is a little dark compared to the D-Log reference to my eye. The HLG image corrected with the DJI D-Log Rec.709 image IS pretty close to the D-Log reference, but might be a bit over saturated. But, the HLG image corrected with the DJI D-Log LUT looks better to my eye than the AG HLG True LUT, though colors are a bit oversaturated.

This is not the best comparison image, but does have lots of greens and brown, and the redwood looking stain on the deck. But except for a bit of oversaturation in color, the HLG corrected with the DJI D-Log LUT looks a bit better than the AG HLG True LUT to my eye.

What do others think and what LUT do you use with HLG?

Thanks...Tom

 

[TomSull]

PS: Using a Surface Book 2 laptop monitor, no attempts to color calibrate it as of yet.

I will need to reshoot a test using the recommended camera adjustments (Sharpness and Contrast) for the AG LUT, which I'll do sometime soon.

 

[brett8883]

Hi, first, I'm a brand new pilot having just gotten my Mavic 2 Pro a couple of weeks ago, and I'm greatly enjoying it. I've gotten DaVinci Resolve 16 for color correction, and started shooting in D-LOG using the DJI D-Log to Rec.709 LUT.
I then tried HLG and saw a bit more color saturation in the raw images, so I thought I'd go looking for LUTs for HLG imaging with the Mavic 2 Pro. HLG looks like an interesting technology for color encoding so I thought I'd play around with it to see how it looks.

I found the Aerial Guide Mavic 2 Pro LUTs and I saw they have an HLG LUT so I purchased the set and tried it against a quicky HLG test video I did.

The images below show the original HLG file at the bottom center, a D-Log image adjusted with the D-Log to Rec.709 reference LUT (as a reference for comparison to HLG) at the right, the Aerial Guide Mavic 2 Pro H.265 HLG True LUT to the right, and at top center, the HLG image color corrected with the D-Log to Rec.7.0 reference LUT.

To my eye, the best match to the D-LOG reference image is to use the SAME DJI D-Log to Rec.709 LUT on HLG as well as D-Log. The Aerial Guide LUT lacks saturation and is a little dark compared to the D-Log reference to my eye. The HLG image corrected with the DJI D-Log Rec.709 image IS pretty close to the D-Log reference, but might be a bit over saturated. But, the HLG image corrected with the DJI D-Log LUT looks better to my eye than the AG HLG True LUT, though colors are a bit oversaturated.

This is not the best comparison image, but does have lots of greens and brown, and the redwood looking stain on the deck. But except for a bit of oversaturation in color, the HLG corrected with the DJI D-Log LUT looks a bit better than the AG HLG True LUT to my eye.

What do others think and what LUT do you use with HLG?

Thanks...Tom

View attachment 100957

A camera LUT is just designed to give you a neutral starting point it isn’t meant to correct your levels or saturation for you. Correct the images and then decide which LUT allowed you more latitude to correct

 

[TomSull]

Hi, first, I'm a brand new pilot having just gotten my Mavic 2 Pro a couple of weeks ago, and I'm greatly enjoying it. I've gotten DaVinci Resolve 16 for color correction, and started shooting in D-LOG using the DJI D-Log to Rec.709 LUT.
I then tried HLG and saw a bit more color saturation in the raw images, so I thought I'd go looking for LUTs for HLG imaging with the Mavic 2 Pro. HLG looks like an interesting technology for color encoding so I thought I'd play around with it to see how it looks.

I found the Aerial Guide Mavic 2 Pro LUTs and I saw they have an HLG LUT so I purchased the set and tried it against a quicky HLG test video I did. Note that this is previous footage so I didn't set the recommended Sharpness and Contrast settings in the Mavic 2 camera, so they're at defaults.

The images below show the original HLG file at the bottom center, a D-Log image adjusted with the D-Log to Rec.709 reference LUT (as a reference for comparison to HLG) at the right, the Aerial Guide Mavic 2 Pro H.265 HLG True LUT to the right, and at top center, the HLG image color corrected with the D-Log to Rec.7.0 reference LUT.

To my eye, the best match to the D-LOG reference image is to use the SAME DJI D-Log to Rec.709 LUT on HLG as well as D-Log. The Aerial Guide LUT lacks saturation and is a little dark compared to the D-Log reference to my eye. The HLG image corrected with the DJI D-Log Rec.709 image IS pretty close to the D-Log reference, but might be a bit over saturated. But, the HLG image corrected with the DJI D-Log LUT looks better to my eye than the AG HLG True LUT, though colors are a bit oversaturated.

This is not the best comparison image, but does have lots of greens and brown, and the redwood looking stain on the deck. But except for a bit of oversaturation in color, the HLG corrected with the DJI D-Log LUT looks a bit better than the AG HLG True LUT to my eye.

What do others think and what LUT do you use with HLG?

Thanks...Tom

View attachment 100957

I lightened up the AG HLG Image LUT as you can see below. Looking at the deck itself, it looks like the D-Log image is itself a little over saturated but the Sun isn't hitting the same part of the deck. The AG HLG is pretty close to my eye when lightened a bit, but a bit under saturated still. I think the ideal lies in between:

 

[brett8883]

I lightened up the AG HLG Image LUT as you can see below. Looking at the deck itself, it looks like the D-Log image is itself a little over saturated but the Sun isn't hitting the same part of the deck. The AG HLG is pretty close to my eye when lightened a bit, but a bit under saturated still. I think the ideal lies in between:
View attachment 100972

Overall a saturation is not something to worry about as global saturation is easily modified in post. You can also adjust your in camera settings to increase or decrease global saturation. The job of a LUT is to aid you in not having to do as many targeted HSL adjustments.

 

[TomSull]

A camera LUT is just designed to give you a neutral starting point it isn’t meant to correct your levels or saturation for you. Correct the images and then decide which LUT allowed you more latitude to correct

Brett, hanks for the response. I was looking at LUTs to get the camera output back to (close to) the Rec. 709 standard. Wouldn't that be a normal first step in processing, or do experienced colorists skip this step?

BTW, looking at the comparison of the AG LUT to the uncolored HLG image, after lightening it up, the colors look pretty close the non modified HLG with a bit more green added. Contrast is increased and the image is darkened a bit, which I lighted for the later comparison. It looks pretty subtle on it's color correction.

The HLG image corrected (probably erroneously) with the D-Log with the DJI Rec. 709 LUT looks VERY close to the D-Log color encoded version with the Rec. 709 LUT.

So, perhaps to better ask my question, a) is it important or desirable when doing image color processing to first correct the image back to Rec. 709 or do those who are experienced skip this step and do color adjustments by eye/histograms?

And b) If it is normal to go to a Rec. 709 corrected image initially, what LUT is used with HLG to do this camera correction?

I was looking at HLG to see if I could also play with HDR Video a bit, given it's a broadcast encoding standard to enable HDR. Is there any real reason to use HLG over D-Log? Does it facilitate HDR in a way that D-Log encoding doesn't?

Thanks yet again...

 

[breid]

This video by Drone Film Guide answered a lot of questions for me as far as color correction and color grading. Hint: always start out by color correcting first to get the exposure right. Once I saw this video, things clicked in place for me.

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[brett8883]

Brett, hanks for the response. I was looking at LUTs to get the camera output back to (close to) the Rec. 709 standard. Wouldn't that be a normal first step in processing, or do experienced colorists skip this step?

BTW, looking at the comparison of the AG LUT to the uncolored HLG image, after lightening it up, the colors look pretty close the non modified HLG with a bit more green added. Contrast is increased and the image is darkened a bit, which I lighted for the later comparison. It looks pretty subtle on it's color correction.

The HLG image corrected (probably erroneously) with the D-Log with the DJI Rec. 709 LUT looks VERY close to the D-Log color encoded version with the Rec. 709 LUT.

So, perhaps to better ask my question, a) is it important or desirable when doing image color processing to first correct the image back to Rec. 709 or do those who are experienced skip this step and do color adjustments by eye/histograms?

And b) If it is normal to go to a Rec. 709 corrected image initially, what LUT is used with HLG to do this camera correction?

I was looking at HLG to see if I could also play with HDR Video a bit, given it's a broadcast encoding standard to enable HDR. Is there any real reason to use HLG over D-Log? Does it facilitate HDR in a way that D-Log encoding doesn't?

Thanks yet again...

HLG has both a Standard Dynamic Range gamma curve and a High Dynamic Range gamma curve hence Hybrid Log Gamma (aka HLG.) To edit HLG as HDR you must work in the correct color space in Resolve and you need a monitor that can display HDR so you can see what you are doing. This is where things get more complicated and I’ll let you do your own research on how to set up Resolve for editing HLG as HDR. But rec 709 is not HDR by definition. HDR video has either blacker blacks or whiter whites than rec 709. HDR still is in its infancy and there competing HDR color types. This is one of the more complex parts of color science and I don’t proclaim to be and expert by any stretch but you can’t get HDR in the rec 709 (broadcast) color space.

The special thing about HLG is that it can be either SDR or HDR and it was developed for the BBC because they anticipate that the nature of broadcast is such that some day all “broadcast” will be in HDR and they don’t want to have all the content they produced up to that point be unusable yet they can’t shoot everything twice, one in SDR for use today and again in HDR for use I. The future, so they came up with something that can do both. HLG is not

Rec. 709 is just a color space with a finite number of colors and a finite number of stops of dynamic range. There’s not necessarily a right way it’s suppose to be.

 

[TomSull]

I do have a monitor that will do HDR400 well enough and I've gone as far as finding the enable HDR option in Resolve and I did a bit of reading on it in their massive tome of a manual, but I still have more research to do.
I tend to be a bit detailed oriented, as you mentioned, the Rec. 709 color space is definitely limited, but I thought that bringing the image to this standard color space would be a standard starting point, but your reply implies that this is not the case. In face, could I lose additional color information if I do this step first as opposed to working with the colors directly? I do have a pretty good eye and I did a fair amount of astronomical image work, which involves a lot of work in each color channel.
I'd also done my homework on HLG (I'm a former math geek) which I was interested in playing with the format and encoded media on different displays. That said, I'm not sure I'd use it much for content since most of my imaging is for nature video/photography, but I DO live in New England and would like to see what I can do with the fall colors, so I'm preparing now.
Again, thanks for the info and the response! I'll post anything I produce if it look reasonable.

 

[TomSull]

This video by Drone Film Guide answered a lot of questions for me as far as color correction and color grading. Hint: always start out by color correcting first to get the exposure right. Once I saw this video, things clicked in place for me.

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Excellent, thanks!

 

[brett8883]

I do have a monitor that will do HDR400 well enough and I've gone as far as finding the enable HDR option in Resolve and I did a bit of reading on it in their massive tome of a manual, but I still have more research to do.
I tend to be a bit detailed oriented, as you mentioned, the Rec. 709 color space is definitely limited, but I thought that bringing the image to this standard color space would be a standard starting point, but your reply implies that this is not the case. In face, could I lose additional color information if I do this step first as opposed to working with the colors directly? I do have a pretty good eye and I did a fair amount of astronomical image work, which involves a lot of work in each color channel.
I'd also done my homework on HLG (I'm a former math geek) which I was interested in playing with the format and encoded media on different displays. That said, I'm not sure I'd use it much for content since most of my imaging is for nature video/photography, but I DO live in New England and would like to see what I can do with the fall colors, so I'm preparing now.
Again, thanks for the info and the response! I'll post anything I produce if it look reasonable.

Resolve is a non-destructive editor and won’t throw out your data until you deliver your content but you can always use a LUT and color corrector on the same node or in a parallel node.