Dynamic Range

[FilmMan]

Here's an example of dynamic range.  I'm only posting this video between Alexa and Red Mx to show the importance of dynamic range.  I'm not supporting or non supporting either camera.  This is an older video.

https://vimeo.com/13352311

Response by Red.
http://reduser.net/forum/showthread.php?47529-EPIC-and-Alexa

Now the BlackMagic is touted to have an incredible DR.  I'm looking forward to some ungraded video from the BM camera for download (as many are waiting for too).

[FilmMan]

Red one had a DR of 11.3 stops,RED MX has a DR of 13 stops,RED EPIC has DR of 13.5 stops natively and 18 stops with HDRx, ALEXA has a DR of 14 stops.  Film roughly 15 stops???

BlackMagic 13 stops and if tweaking is successful, perhaps 14 to 15???  Wow.

[FilmMan]

Old Article on DR:
http://provideocoalition.com/index.php/aadams/story/canon_5d_how_much_dynamic_range_does_it_have_really/

Remember this:
http://www.zacuto.com/the-great-camera-shootout-2011/episode-one

[shijan]

Dynamic range regarding to zacuto tests:
[IMG]http://i49.tinypic.com/2gse9gg.jpg[/img]

BTW they are just announce the 2012 test available at may 9 for:

• Sony F65
• ARRI Alexa
• RED Epic
• Sony FS100
• Sony F3 w/slog
• Canon C300
• Canon 7D with Technicolor settings
• Panasonic GH2 (hacked and non-hacked)

http://www.zacuto.com/shootout-revenge-2012
wish them only do their measuring there with less pathos and popcorn :) :) :)

[FilmMan]

The DSLR's supposedly are closer to 10 stops? 

So the BM with 13 stops is awesome.  I'm curious how much better the calibrated sensor will be.  I wonder if they'll be able to push 14 stops?  or perhaps close in on 15 stops? 

[shijan]

those few more stops are not so simple to do. i believe 13 stops its camera limit, which is still pretty cool. and they should correct first those strange color blocky sensor noise.

[FilmMan]

Shijan,
I read some wheres that they might be able to bump it up a stop or two.  I'm not holding my breath, as 13 stops is awesome. 

[Simco123]

[quote author=FilmMan link=topic=660.msg4881#msg4881 date=1335746689]
The DSLR's supposedly are closer to 10 stops? 

So the BM with 13 stops is awesome.  I'm curious how much better the calibrated sensor will be.  I wonder if they'll be able to push 14 stops?  or perhaps close in on 15 stops?
[/quote]

Yes dSLR such as the 5D2 has high DR that is why you see highlight roll off unlike the GH2 were it clips highlights. Had a hard time convincing some on here to accept that ::)
The low bitrate put it at a disadvantage for grading plus other negative like downsampling and not RAW.

[shijan]

[quote]
Yes dSLR such as the 5D2 has high DR that is why you see highlight roll off unlike the GH2 were it clips highlights.[/quote]

i also have theory that canon DSLRs has some kind of tricky digital limiter for highlights. those burning holes always looks smudged by yellowish paint on canon footage :)

[Axel]

[quote author=shijan link=topic=660.msg4880#msg4880 date=1335743565]
Dynamic range regarding to zacuto tests:
[/quote]

That the EOS show over 11 stops is misleading. This is relevant for a raw photo, not for the movs. Color-pick different values below 15 in 8-bit (i.e. 0/0/0 compared to 11/6/10) and see if you can distinguish them. That makes the row 16-32-64-128-255, five stops. As long as Magic Lantern doesn't change it (and I bet it can't be changed), videos from the common DSLRs will never have a DR worth mentioning.

Given you had a raw recording and had to deal with it in your 8-bit environment. Within the same contrast ratio (always assuming you work under optimzed circumstances) you only can shove around curves. Compared to your usual H.264, nothing is baked in, but also nothing is reliable.

Certainly for many this is no spoiler. They [i]want[/i] to have more freedom. That reminds me of [i]Spiderman[/i], where great power means great responsibility. At the end, staying 8-bit, [i]you[/i] have to bake in the values. Ever color-corrected a series of raw photos, one by one? Quite tricky to get them look the same (to "grade for consistency"), isn't it?

If you use a preset, a LUT, the raw video on your monitor will look more or less like your detested H.264. The latter, distorted for look-purposes in your CC-application with 32-bit accuracy, will look [u]the same[/u] in the end. Fact.

Of course, only if you exposed as dynamic as possible and as flat as necessary (that means, preserving values for all parts of the image).

That makes raw for 8-bit an excuse for sloppy exposure and white balance.

Imho the DR [i]of the camera sensor[/i] right now is of importance to very few of us. The correlations of exposure, lighting and the ability of our current hard- and software regarding the optimization of DR are very important, on the other hand.

If the awareness for finer rendering of hues and colors becomes common in near future, if people finally develop "an eye" for those, we will abandon 8-bit and leave them for office computer monitors and never look back.

[quote author=Simco123 link=topic=660.msg4886#msg4886 date=1335761051]
Yes dSLR such as the 5D2 has high DR that is why you see highlight roll off unlike the GH2 were it clips highlights. Had a hard time convincing some on here to accept that ::)
[/quote]

The sensor reads more stops, in both cameras. What we see as sudden clipping, banding or posterization (perhaps not the right term, I just named it after a filter that simplified colors to provide a pop-art-look) is caused by the quantizer, a software-based tool of the camera-processor, dynamically bending the curves according to the needs of the image. A cut off (clipping) has too few steps, a soft roll-off enough (taken from the image parts that currently don't need them). Influenced by picture styles / film modes also, possibly influencable by hacks, but I'm not sure. Hardly by higher bitrates, as the GH2 recently proved. Problems tend to occur more often with dialed up contrasts [u]and[/u] the contrary, a too flat curve (banding i.e. is typical for soft grades with the Lumix' [i]cinema[/i] film mode). You can very easily shoot too flat. Never give away dynamic range! More suggestions?

[cpc]

Axel has given a nice overview.

Raw dynamic range, baked dynamic range and usable dynamic range should be distinguished.

Raw dynamic range is the range of the raw quantized signal.

Baked dynamic range is the range when the raw data is further quantized according to the output bit-depth. For example. Canon DSLR Raw is 14-bit and the output movies (and jpegs) are 8-bit. 8-bit images in general do not exceed 9 stops DR because they are meant to be shown on consumer 8-bit displays. Add more DR and the image starts looking HDR and lacks contrast. 8.3-8.5 stops is typical.

Usable dynamic range is the DR that contains recognizable detail. And detail that can be played with in post. This is around 6 stops for a typical gamma encoded 8-bit video. The darkest stops have some tonal gradation but not any real detail.

Here is a more detailed overview on [url=http://www.shutterangle.com/2012/canon-picture-styles-shooting-flat-or-not/][u]picture styles and dynamic range[/u][/url] that I've written recently.

Highlights can't really be saved on a DSLR camera (and most digital cameras, for that matter) because baked DR is usually mapped at the upper limit of the RAW DR. This is because the higher stops of RAW DR have the cleanest signal, due to high signal to noise ratio in there. Blacks, on the contrary, are always noisy and thin because the SNR is low. This is also the reason that noise gets excessive when blacks (underexposed areas) are pushed up in RAW processing.

[FilmMan]

Good replies everyone.