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Inspired by discussion triggered by my PREVIOUS POST on this topic, and after watching an interview with Alister Chapman, I experimented with HLG footage a bit more (without a special HDR Monitor). This time, rather than converting HLG clips to Rec.709 clips, I created a new video in true HLG format, to see how it would work for both HDR and SDR TVs. I actually ended up creating two versions of the same video. Both versions were created with the same Video Codec: ‘HDR TV’ version – in this version I wanted to see what would be the quality of the video without any color grading (okay, almost no color grading) ‘SDR TV’ version – in this version I did some minimal color grading to get an image quality on an SDR screen similar to the one an HDR screen (in my subjective opinion). I selected several video clips that I shot in HLG (BT2020 color space) at different depths (from 5 m to 35 m) and did the following (mostly following Apple’s recommendations): 1. Created a library in FCPX and set it to Wide Gamut HDR 2. Imported all clips to this library 3. Slightly adjusted Midtones by lowering brightness to -0.1 (this what I understand Alister Chapman has recommended) 4. Slightly adjusted Hue vs Hue of Hue/Saturation Curve of a few clips to change water color from greenish to blueish. 5. Slightly increased sharpness (3.78) 6. Applied HDR Tool (PQ Output Tone Map) 7. Shared the project as a Master File, using Video Codec: Apple ProRes 422 and Wide Gamut HDR - Rec. 2020 HLG color space 8. Uploaded the Master file to YouTube As you can see from the above steps, I basically did not do any color grading, and all above steps took me only about 5 to 10 min, as I was using adjustment layers, to which I applied most adjustments, rather than to individual clips. Here is the LINK to the 'HDR TV' version of the video. When I watched this video on the my HDR TV (Samsung Q80R, 2019) I was quite impressed with its quality. Then, I watched the same video on my old plasma TV and a 2-year old HDR TV, on iMac, on MacBook Pro (2018), on iPhone X, and on my new Dell laptop (2020). I noticed that colors on these screens got 'washed out' a bit, compared to colors on my HDR TV. So, I decided to create another version of this video (‘SDR TV’ version), in which, in addition to the above steps 1 to 8, I made the following adjustments to increase contrast and brightness: 1. Increased brightness of Highlights up to +0.21 2. Decreased brightness of Shadows down to -0.22 for some clips 3. Increased saturation of Midtones slightly As a result, I got a video with quality quite comparable to the ‘HDR TV’ version (in my humble opinion). As such, it appears that for people who do not watch YouTube videos on an HDR TVs the second version ('SDR TV') would work better. Here is the LINK to the 'SDR TV' version of the video. Most probably, quality of this second video could be improved further by making some additional adjustments, but I already see that shooting in HLG underwater could produce very good quality videos (at least to my taste) without much grading and without a special HDR monitor. I should note, however, that I am not sure how good could be quality of underwater footage shot in HLG picture profile using other cameras. With SONY cameras like the one I have (Sony FDR-AX700 / HXR-NX80 / PXW-Z90), it is very easy to set manual white balance underwater with just one click, and I did it for every single shot. Sometimes, however, when there is not much ‘white’ color in a scene to be used by the camera for reference, you have to experiment a bit, and this is where the mastery is. I am not there yet, and I need to practice more to improve this skill. Also, I would like to mention that I am not an expert in HLG, and if anyone is interested in learning more about advantages of HLG I would refer to experts like Alister Chapman. If you would like to learn more about using HLG in underwater videography, I would refer you to J. M. Núñez’s WEBSITE. Juan has tonnes of experience in shooting HLG underwater, and his website is full of very useful and practical information and tips. Please share your opinion about picture quality of the two versions of my video on HDR and SDR screens when you have time. Thank you all. Stay home and stay healthy. Val

During my last trip to Raja Ampat I tried shooting HLG (Hybrid Log Gamma) with my new camcorder Sony HXR-NX80. Before the trip I had no intention of shooting with HLG, but Juan Miguel Núñez Arellano (http://wetpixel.es) encouraged me to do so and mentored me during the trip providing me with valuable tips, and later - he guided me through post-processing of HLG footage. I am very grateful to Juan for all his time and mentoring. You could visit Juan's YouTube Channel to see his footage shut using HLG and recommended settings. The following video is a collection of 4K underwater video clips shot in HDR HLG, BT2020 color space at various depths: https://youtu.be/JaL6gkwfJQY The following equipment was used to make this video: Camera: Sony camcorder HXR-NX80 Housing: Gates AX700 / Z90 with Gates GP34A Wide Angle Port and internal UR Pro Red Filter Video Lights: Keldan Video 8X 11,000 Lumen CRI 92 (5400K) with Keldan Ambient Filter M1 (10-20m) for 4X/8X Camera Settings: 4K, 30 FPS, Picture Profile: BT2020. I followed this ARTICLE for recommended camera settings. All clips were converted to Rec.709 color space using the following two methods: 1 - FCPX HDR Tool 'HDR to Rec.709 SDR', and 2 - Lemming Camera LUT 'Pro Sony A - HLG to Rec.709 and Custom LUT 'Quicker - Neutral Film'. Please note that: Clip #13 is a comparison between FCPX HDR Tool and RAW file. Clip #14 was shot using SDR Rec.709. Clips #12, 13 and 14 were shot at the same point (Cape Kri site at 35 m) and at about the same time (at about 8:30 am), but clip #14 was shot a different day. It is my understanding that the optimal depth range for the UR Pro Red Filter and Keldan Ambient Filter is between 10 and 20 m, and I found it to be a bit more challenging to grade footage shot outside of that depth range. In most cases, the difference between grading using the above two method is very minor, but I found that grading using Lemming Camera LUT gives a bit better result compared to FCPX HDR Tool (except of Clip #13), but it could be due to a lack of my experience. Also, I should mention that I did not use much video lights as as specific situation demanded. I will keep experimenting with HLG on my next trip. Meanwhile, if you have any questions please let me know. In addition, I will appreciate your comments and constructive criticism. I numbered all clips for the convenience of referencing to them. Best regards and thank you.

Here is my first video using Sony camcorder HXR-NX80 taken during the last diving trip in Philippines this August: https://youtu.be/XZ2JvM6JXkI I have not mastered this camera yet, and on a few occasions I inadvertently used wrong settings (i.e. the internal ND filter was on on a few dives). Also, playing with different settings and filters resulted in some color inconsistencies between different clips. While I am still trying to master this camera, I will greatly appreciate constructive criticism and recommendations. The following equipment was used to make this video: Camera: Sony camcorder HXR-NX80 Housing: Gates AX700 / Z90 with Gates GP34A Wide Angle Port and internal UR Pro Red Filter (on most dives) and UR Pro Pink Filter (on a few dives) Tripod: Gates Tripod Diopters: SAGA +5 Diopter Achromatic Close-Up Macro Lens, and SAGA +10 Diopter Achromatic Close-Up Macro Lens Video Lights: Keldan Video 8X 11,000 Lumen CRI 92 (5400K) with Keldan Ambient Filter M1 (10-20m) for 4X/8X Camera Settings: 4K, 30 FPS, Picture Profile: BT709. I followed the following article for recommended camera settings: AX700-Z90-Housing-Recommended-Settings-R2.pdf In my decision to buy this camera and housing, I followed an advise from Juan Monterey, who convinced me through his articles that this Sony camcorder is one of the best cameras for underwater videography: http://wetpixel.es/mi-actual-equipo-submarino/ As I am shooting only videos, I found many advantages of going with this camcorder and the Gates housing, including but not limited to the following: No need to carry several lenses. With one wide angle dome and diopters you could shoot wide angle and macro on the same dive. Very good and fast auto focus Very easy (one-button touch) white balance setup. Ability to use HLG - Hybrid Log Gamma (In the future for me) Battery is good for four dives (about 4 hrs) One things that puzzled me with this Gates housing is providing a control knob for ND filters, as I have never been in a situation yet when there is too much light under water. Maybe someone could enlighten me about this. For all footage above water I was using iPhone X. Hope to hear your comments and recommendations on how to improve my videos. Many thanks and cheers.