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#21 Interceptor121

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Posted 19 August 2018 - 12:57 AM

There is a white paper out there for the VLOG-L have a look it gives all the details. Can't upload files here or don't know how to.

I have read two documents on panasonic professional
One is the varicam VLOG/VGamut this applies to the varicam cameras that are professional level recorders here there is the full low down on dynamic range color gamut etc
The second is a paper on production considerations for the DVX200 that shares the same processor of the GH4 there is no mention of what the color space is and clearly this implementation of vlog is a castrated version of the varicam
To finish off Panasonic only provides LUTs for REC709 so this looks like the camera uses vlog l gamma to compress within rec709 and then uses the LUT to decompress gamma back into rec709
I have found out a company called mysterybox that provides custom LUT to capture BT.2020 HDR10 using inferno or other monitors
Without that workflow you can only convert to REC709
I suppose using a set of 3 LUTs to accomplish a few more colours is out of reach for your normal underwater production and you might as well use HLG that requires no LUTs


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#22 bubffm

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Posted 19 August 2018 - 02:19 AM

I suppose using a set of 3 LUTs to accomplish a few more colours is out of reach for your normal underwater production and you might as well use HLG that requires no LUTs
 

 

Don't forget that HLG is a delivery format! It is build to be used/consumed as-is (news-delivery, broadcast etc..) and as soon as you start grading/correcting it, it will fall apart pretty quickly. Thats what anyone will tell you, and I've actually tried it out myself.

So if you are likely to have post-work to do (as is almost always the case for underwater footage), than VLOG is the better format as it behaves much better - at least in 10bit.


Edited by bubffm, 19 August 2018 - 02:19 AM.


#23 Interceptor121

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Posted 19 August 2018 - 02:54 AM

 
Don't forget that HLG is a delivery format! It is build to be used/consumed as-is (news-delivery, broadcast etc..) and as soon as you start grading/correcting it, it will fall apart pretty quickly. Thats what anyone will tell you, and I've actually tried it out myself.
So if you are likely to have post-work to do (as is almost always the case for underwater footage), than VLOG is the better format as it behaves much better - at least in 10bit.

Other than not having the right equipment to display it why would it fall apart more than cinelike D? VLOG requires noise reduction in post and therefore for me is not a good option. I tend to do very little color correction in post best case white balance and usually have more interventions on contrast and saturation than colouring
I believe underwater video is closer to broadcasting than studio production so the focus is to get it right in camera as much as possible and do as little as possible later and not the other way around. What kind of issues do you get with HLG? I am aware that there are no monitors to do proper grading but in my land experiments with 150 mbps 422 that is a crap codec I see no major issues other than the inadequacy of my set up my other choice would be cinelike D rec709 but why loose all deep colours at the outset?


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#24 bubffm

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Posted 19 August 2018 - 03:50 AM

Its related to the gamma curve that HLG uses. This is probably a good read:

http://www.xdcam-use...to-be-used-for/

Not just theory, try to grade HLG and youll see it fall apart quickly (as observd on my HLG capable Loewe TV), certainly much quicker than Cinelike D (my favourite for underwater) or LOG.

But of course if you dont work on your footage in post, HLG may work for you. Even correctly WBd, I always have quite a few things I want to improve in post.

Id also challenge your point that UW stuff is closer to broadcast than to studio. The very inventors of HLG (BBC) have massively graded their BP2 footage in post studio, not rolled it out as shot.

Edited by bubffm, 19 August 2018 - 03:56 AM.


#25 Interceptor121

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Posted 19 August 2018 - 04:07 AM

Its related to the gamma curve that HLG uses. This is probably a good read:

http://www.xdcam-use...to-be-used-for/

Not just theory, try to grade HLG and youll see it fall apart quickly (as observd on my HLG capable Loewe TV), certainly much quicker than Cinelike D (my favourite for underwater) or LOG.

But of course if you dont work on your footage in post, HLG may work for you. Even correctly WBd, I always have quite a few things I want to improve in post.

Id also challenge your point that UW stuff is closer to broadcast than to studio. The very inventors of HLG (BBC) have massively graded their BP2 footage in post studio, not rolled it out as shot.

This article refers to the Sony fs5 that as I can read is 8 bits
I see the point about correcting highlights and shadows separately
Still I believe LOG is not for me and rather do cinelike D
I also agre that the fact the camera supports bt2020 does not mean at all it will cover it and in a single shot the GH5 is not likely to exceed 24 bit colors anyway but still capturing 10 is best practice
On the other argument VLOG gamma is even more compressed than HLG and there are HLG grading luts available



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