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maxotics

What was the first professional camera to shoot LOG gamma?

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@maxotics I already said 10 bit on a consumer camera like the GH5 is not the same as 10-bit Arri, or 12-bit or whatever. My point is not to argue bits but that HDR requires either log or RAW. You stay focused on bits if you like. Just another diversionary tactic. 

@HockeyFan12 Of course a film in Dolby Vision shot with an Arri is going to be superior to a small sensor camera, but the results you can achieve with HDR on consumer cameras are still dramatically better than SDR. And there is a huge difference between delivering to YT in HDR vs SDR. 

 

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EOSHD Pro Color for Sony cameras EOSHD Pro LOG for Sony CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs
1 hour ago, maxotics said:

It's the same thing with your helicopter shot.  If you look for rich colors you won't find it in the HDR. 

Honestly, I was trying my best to give you an open mind and not disagree with you, but if this is what you think, without even experiencing it in person, then I disagree with everything you've been saying. It's frustrating that you've already come to a conclusion without actually experiencing it.

HDR is more nuanced. It's more detailed. It's more pleasing in every single regard, including color.

If you can't see that in the iPhone photos, fine, but take my word for it - in person, the kind of saturation in the 2K BD is gross. As is the contrast.

1 hour ago, maxotics said:

Your example above demonstrates my point.  In the non-HDR version of the truck the red headlights are nice and saturated.  

I'm sorry again, but you're just not speaking from a credible position here. If by saturation you mean there are fewer variations in color (IE the computer technical definition), sure, but it makes the image look like it was shot on an iPhone 4. I could easily make the HDR look just as sh*tty as the SDR version if I cranked up the saturation and fake contrast controls on the TV. Maybe I'll do that later to show you.

1 hour ago, maxotics said:

If you look for rich colors you won't find it in the HDR.  

This is literally the statement where you lost me completely. This is absolutely 100% unequivocally incorrect. SDR colors look like Crayola colors in comparison to the HDR version. I guess I disagree with your definition of "rich colors," entirely.

 

Please, PLEASE stop any further disbelief in HDR until you do this kind of true comparison in person. Until then, I don't think you have credibility speaking on this subject.

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If Apple shipped 80 million phones in the fiscal first quarter of 2018, then the total number of HDR displays in the world must already far exceed the population of all of North America. And the format is still in its infancy! By way of contrast, OLED television shipments in 2017 amounted to 1.4 million, with LG owning over 90% of the market.

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The reason I asked Max at what point the trade off between a small loss of color information for significant gains in dynamic range is worthwhile is the following: if shooting log on the GH5s and finishing in HDR allows me to see the full 13 stops of dynamic range (as opposed to 6 stops in SDR), it would seem to me that the benefits far outweigh the penalty. 

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On 2/2/2018 at 8:41 PM, maxotics said:

My monitor can go brighter.  For more DR that is what you do.  Again, brightness is not encoded in your video, it is assumed you'll set your display's physical brightness range to match.  You want 8 stops of DR, if your monitor can do it, just up the brightness!  I don't, because IT IS UNCOMFORTABLE.  My eyes can't tolerate it.  To anyone who says they want more DR I say, take out your spot-meter, set your display to 7 stops of brightness and determine what that REALLY means to you.  Don't just read marketing crap.  See for yourself :) (I'm talking to "you" as in anyone)

This demonstrates a fundamental lack of understanding of what HDR is. Turning up the brightness of your monitor does not suddenly transform it into HDR. And HDR is not marketing crap. 

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4 minutes ago, IronFilm said:

Meh, I was writing up a long response..... but then  thought, nah! Not going to bother. But there is no way to delete posts in this forum :-/

I'm afraid I'm about to make another TLDR posting ;-)

What's meant by Dynamic Range?

Someone above said common rec_709 displays could show 7 stops of light at best. This is the standard. Let's therefore agree to call it SDR.

Many modern cameras can record 10-13 stops. A linear recording (picture profile-related) would only be able (hypothetically, see below) to store an excerpted range of nine stops. Due to broadcast-rules, the values below 16 and above 235 were considered 'illegal', because they couldn't be truthfully reproduced. That's the background to 7 stops of light at best

But none of the non-LOG profiles bakes in a truly linear curve, because that would look terrible. They reserve most of the values for the midtones and rob some of the wasted 20 superwhite values. The image of a standard picture profile - often called Standard - tends to look punchy as well as natural. Most of the time this is actually what one wants to achieve.

There are also profiles that favor skintones ('Portrait' - for Sony mirrorless the creative style Autumn Leaves has become popular because it additionally has a color shift complimentary for skin), lanscapes and so on. I don't know the exact numbers, but let's assume that there will be 50-60 values reserved for the skin range then.

A LOG quantization curve tries to distribute more or less (there is a knee for superwhite usually) the same amount of values for every stop of light into that 256 scheme. For the Sony A7sii, which claims to record 14 stops @Slog3, this would mean 18 values for each stop (it may be somewhat more complicated, but for the sake of simplicity, let's agree upon that simplification).

One term that currently came up in conjunction with the new GH5S' dual ISO is *useable dynamic range*. Tom Antos' tests to verify the actual dynamic range of cameras showed that all LOG recordings capture the noise floor too, so one has to substract one stop for the shadows. But there are limiting factors for the highlights too. If a daylight sky's gradient does show banding in Slog-3 in a graded rec_709 version, where in-between-values are being interpolated with floating point accuracy in post, one can imagine how this will affect HDR. 

Admittedly I am not a broadcast engineer. But taking all of he above into account, I'd say that 10-bit or more is needed to really extend the DR. Please comment and correct my arguments.

Now for a subjective point of view:

We still live in an SDR world. Seven stops. Light is just white, a dull color mix of RGB. 13 stops of light crammed into rec_709, lifting shadows, preserving highlights, results in the kind of artificial-looking images we often see when people record in LOG. If light is the subject, if it's prominent in the image, I consider this counterproductive and pathetic. It's better to let the highlights clip, to let the 100 IRE white eat away the detail. I found an image to demonstrate what I mean:

2.jpg

Always?

No, but the unwritten law to never let the highlights clip is stupid, imo. Light is not just an informal part of the environment, it's an epiphany. I like a punchy image more than an expressionless one. Oh, Larry, well done! I really see detail in the clouds, terrific!

 

 

 

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I find her smile beguiling, but the absence of tonality in her shirt makes me wary of approaching. ? Let’s get real - wide dynamic range isn’t always about maintaining detail in every highlight. Having wide dynamic range gives the filmmaker and colorist more creative freedom to decide what is or isn’t important.

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7 hours ago, Axel said:

Admittedly I am not a broadcast engineer. But taking all of he above into account, I'd say that 10-bit or more is needed to really extend the DR. Please comment and correct my arguments.

Yes, it is.  The question is how 10-bits are measured.  In RAW, 10-bits would mean 1,024 values of each R,G,B value.  That is certain more dynamic range than storing 256 values (8-bit).  If we're talking about 10-bit, in the first sense, we need 1,024 x 1,024 x 1,024 = 1,073,741,825 full-color values.  What amount of memory do you need to store a pixel's color in that range?  I'm attaching a table of data that I suggest studying and thinking about.  

The truth is, 10-bit is not 10-bit the way you (and I) would like to think about it.  The extra 2-bits goes into reducing chroma-subsampling, or the the amount of color compression the camera does across macro blocks in an 8-bit dynamic range.  It does not increase a pixel's dynamic range! You can see this in the Panasonic GH5 specs I included.  

bit-rates.thumb.png.5bb9e73514b0e580689e9e3d9a0b50e1.png

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8 hours ago, jonpais said:

why bother is right. I had to double up on my Amlor. ?

You guys are killing me!  You know, I want to be as liked as the next guy.  When I first started this stuff years ago I got into a huge fight with someone on the Magic Lantern forum.  I insisted each pixel captures a full color.  I went on and on and on.  Much like you guys are doing to me. I feel shame just thinking about it.  In the end, I learned 2 things 1) What a CFA is and what de-mosaicing does and 2) Always consider the possibility I might be not just wrong, but horrendously, embarrassingly wrong.  It's what we do after learning our errors that define us (hint, hint @IronFilm).  Anyway, after the MF thing I try to be like the guy who educated me.  He didn't give up on me and I'm glad he didn't....but it's hard.

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41 minutes ago, maxotics said:

You guys are killing me!  You know, I want to be as liked as the next guy.  

I like you I just think you're wrong.

JK ; ) - Seriously though I just disagree about benefits outweighing the costs. I believe you that there are certainly drawbacks to trying to cram so much info into a small container; as I mentioned I don't shoot SLog nearly as much now, after reading some of your posts. But I know, having compared the HDR and SDR masters of a huge-budget feature, that ultimately HDR is more pleasing to me.

I do appreciate all your posts though! They're educational and make me think. And your posts back in June are actually the reason I even signed up for a forum account... I signed up to argue with you about S Log :lol::bawling:

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