Author Topic: Cinelog - True logspace conversion for DNG and CinemaDNG footage  (Read 540033 times)

Andy600

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #125 on: April 21, 2014, 05:48:56 PM »
@reddeercity - not sure who you are disagreeing with but an underexposed image, converted to log without first adjusting exposure when it's still raw, will still be under exposed after conversion and the image will exhibit more noise as a consequence of adding offset/gain. Correct exposure is of course fundamental to achieving the best SNR and usable dynamic range. Log is not a fix for underexposure.
Colorist working with Davinci Resolve, Baselight, Nuke, After Effects & Premier Pro. Occasional Sunday afternoon DOP. Developer of Cinelog-C Colorspace Management and LUTs - www.cinelogdcp.com

CF

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #126 on: April 21, 2014, 06:32:25 PM »
@CF - Thanks for your post :)

You seize on one word but neglect to mention several beneficial reasons for converting raw to Log. Not least of which is storage, archiving and efficiency of workflow.



Applying a logarithmic curve to an image does NOT, as above implies, convert RAW to Log. The image is STILL RAW, it is just being 'lifted' / 'Compressed' into a diff. gamma space.

This is what I mean, all this false word-mangling - to confuse a subject which at this present moment is about THE most confused topic on the web... (Next to how to keep a retina display clean)....

A REAL great advantage of a LOG Curve is when debayering is done In-Camera.... Before 'Converting' RAW to a Codec or 'Baking in' the linearization curve. When working with RAW files, it is pointless to use any ONE standard linearization curve (Log). It is VERY limiting, in fact. It would be like trying to apply ONE color-correction to each and every other clip. Which any colorist would know would be non-sense.

I LOVE working with RAW, as I don't have to work against any LOG Curve previously applied to the image. And I ALWAYS start with the linear representation of the image. Then I'll apply gamma to that. And to imply that applying an Rec709 workspace-LUT to a RAW-image will make it look like 'This and That' and adhere to this or that standard, is simply put; Wrong. After 'Putting' something into another 'Space' does NOT imply NOT having to further apply gamma, gain, offset etc. to that particular image... Gamma IS a logarithmic curve or function if you will...

When shooting RAW - the Canon Camera does NOT apply ANY Linearization Curve to the image. Hence RAW.... When shooting H.264 is DOES apply a curve to the image. And in THIS case of in-cam-debayering, the LOG Curve becomes important... CineStyle was a GREAT example of that. Technicolor KNOW what they are doing. But it would be UTTERLY non-sense to shoot RAW and then i.e. in Lightroom apply the Cinestyle LOG Space to the RAW-image. When shooting RAW, you HAVE to realize that you have the FULL DNA of the image-data, RIGHT THERE in the palm of your hands with all its might at your disposal. Simply loading a LUT with a generic LOG-Curve and apply that to each image, would be limiting yourself in EVERY regard.

Understanding RAW and how to develop it, is paramount for anyone shooting it. RAW is wonderful and just as wonderfully misunderstood and therefor, easy to make money off of.

Anyone, NOT 100% sure of what RAW is and how to handle it, should spend their good money on a good tutorial or book, rather than a LUT ;-)


DavidSh

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #127 on: April 21, 2014, 06:44:02 PM »
Applying a logarithmic curve to an image does NOT, as above implies, convert RAW to Log. The image is STILL RAW, it is just being 'lifted' / 'Compressed' into a diff. gamma space.

This is what I mean, all this false word-mangling - to confuse a subject which at this present moment is about THE most confused topic on the web... (Next to how to keep a retina display clean)....

A REAL great advantage of a LOG Curve is when debayering is done In-Camera.... Before 'Converting' RAW to a Codec or 'Baking in' the linearization curve. When working with RAW files, it is pointless to use any ONE standard linearization curve (Log). It is VERY limiting, in fact. It would be like trying to apply ONE color-correction to each and every other clip. Which any colorist would know would be non-sense.

I LOVE working with RAW, as I don't have to work against any LOG Curve previously applied to the image. And I ALWAYS start with the linear representation of the image. Then I'll apply gamma to that. And to imply that applying an Rec709 workspace-LUT to a RAW-image will make it look like 'This and That' and adhere to this or that standard, is simply put; Wrong. After 'Putting' something into another 'Space' does NOT imply NOT having to further apply gamma, gain, offset etc. to that particular image... Gamma IS a logarithmic curve or function if you will...

When shooting RAW - the Canon Camera does NOT apply ANY Linearization Curve to the image. Hence RAW.... When shooting H.264 is DOES apply a curve to the image. And in THIS case of in-cam-debayering, the LOG Curve becomes important... CineStyle was a GREAT example of that. Technicolor KNOW what they are doing. But it would be UTTERLY non-sense to shoot RAW and then i.e. in Lightroom apply the Cinestyle LOG Space to the RAW-image. When shooting RAW, you HAVE to realize that you have the FULL DNA of the date, RIGHT THERE in your hands with all its might at your disposal. Simply loading a LUT with a generic LOG-Curve and apply that to each image, would be limiting yourself in EVERY regard.

Understanding RAW and how to develop it, is paramount for anyone shooting it. RAW is wonderful and just as wonderfully misunderstood and therefor, easy to make money off of.

Anyone, NOT 100% sure of what RAW is and how to handle it, should spend their good money on a good tutorial or book, rather than a LUT ;-)
Dear CF,
Thank you for your very detailed explanation,
As one who do not know about raw as you...
Why is there log space tab in speedgrade let say, containing rec709 and arri alexa and red etc'  if log space is not needed?
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CF

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #128 on: April 21, 2014, 06:46:31 PM »
@reddeercity - not sure who you are disagreeing with but an underexposed image, converted to log without first adjusting exposure when it's still raw, will still be under exposed after conversion and the image will exhibit more noise as a consequence of adding offset/gain. Correct exposure is of course fundamental to achieving the best SNR and usable dynamic range. Log is not a fix for underexposure.

From what I was understanding, he meant that ANY imperfection in the image will be amplified by the application of the Log Curve. Which is true. There is NO... ONE log curve, for all images. This 'beloved' curve is totally dependent on exposure, weather conditions, specular highlights, fog etc etc etc.... with RAW... USE THE GAMMA, GAIN, OFFSET, LIFT or whatever exotic names your sliders are carrying, to get the image developed...  Using a static LOG-Curve is a compromise and the better the know-how the better the result. ARRI is one company which Curves', Spaces' (whatever you wanna dub them) are great. Could one get better results without them... YES... IF he had the right knowledge of how to develop the images.

RAW is like negatives... You need a good developing-Lab to get good results.

DavidSh

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #129 on: April 21, 2014, 06:51:25 PM »
RAW is like negatives... You need a good developing-Lab to get good results.
Very nice analogy.
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CF

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #130 on: April 21, 2014, 07:22:04 PM »
Dear CF,
Thank you for your very detailed explanation,
As one who do not know about raw as you...
Why is there log space tab in speedgrade let say, containing rec709 and arri alexa and red etc'  if log space is not needed?

Speedgrade, handles all kinds of image formats and codecs... If footage has been shot in a LOG Space - it 'could' 'can' 'will' make sense to apply either an inverse of that particular log or directly operate on that image in Log-Space... It is diff. to explain without showing it off on a screen to someone without programming Experience... But in a nutshell - when applying a simple 'gain' to the vectors (RGB Channels) higher numbers (Pixel Values) will be more influenced, relatively, by that gain than lower numbers... When using a gamma function the closer any given number is to 0 or 1, the less the influence of the gamma function. So if you apply gamma to footage residing in a log space you will most likely affect the overall.

I know it seems complicated, but in reality it is not... Speedgrade has to deal with so much different footage, and has but one set of sliders, doing offset, gamma and gain. For those controls to work as intended, one would need 'stretch' the image to his advantage, so that gain affects the particular area of interest.. For instance... There is no such thing as a real offset. An offset can be achieve in several ways... (Try this yourself in Speedgrade) Click the plus button in the layers palette and load up the fxInversion... Invert ALL channels. Now duplicate the fxInversion layer.. When both layers are inverting you won't see the actual result... Now do this... Create a Primary Layer and move it, in between the two inversion layers. Now adjust the gain slider of the primary. The effect is an offset or Blacklevel or whatever you wanna call it.. The function is ---- 1.0 - theImage.rgb (This will invert the image and make the blacks white and vice versa... Then you apply gain to that results... --- theImage.rgb * 1.5 (Multiplication has greater effects on higher numbers the blacks, that are now whites will increase... After this, we re-invert the image so that the blacks (now whites) become black again.. 1.0 - theImage.rgb.... Programmatically, one would optimize the algorithm to look something like this    1.0-(1.0-(theImage.rgb*1.5)) - but above serves the explanation better. To take it even further, to affect certain areas of the blacks more than others, one would apply a power function to the above algorithm and you would then have a slider often referred to as a Pivot...

I hope my attempt to explain the matter was not too weird !

CF

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #131 on: April 21, 2014, 07:40:58 PM »
I personally love Speedgrade and the way it handles RAW. It serves me the images as Linear as they are. All green, very ugly and extremely unusable, initially. However, I can do ANYTHING to them that I want - a developers dream. And I don't need to work against any Lightroom, Da Vinci Resolve Linearization Curves. It is easier to apply to a linear RAW, the amount of Gamma or whatever one needs than to try and take it off those auto-pilot algorithms. Resolve to me is like Lightroom - Automatic as H*** and I don't like that. SG (I am NOT working for adobe) is IMO the most fantastic software I have ever used.
Weird and ugly interface, almost no documentation but with a POWER and potential that no other app has ;-)

So if anyone wants to learn, get a premature heart attack, get unprecedented development possibilities and have fun all at the same time, try Speedgrade ;-)

Andy600

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #132 on: April 21, 2014, 07:51:34 PM »
@CF - I think you are completely missing the point of Cinelog. Several in fact. Which is odd, because I explained them clearly. ???

Of course, working with the raw digital negative DNG will give you the most options and the best quality. I even said so clearly in my reply to you  ::)

BUT

How are you archiving your footage? Are you storing all your raw files? Are you working on features running into hundreds of GB or more of storage for your DNGs? Have you got a very fast machine to debayer raw in realtime or are you using proxies? (another step). It may come as some surprise to you but the majority of people here are not working on the latest Mac Pro with huge raids and infinite storage. My guess is that if anything you are probably working with Cineform raw!? Which I even recommended OVER AND ABOVE any other method including Cinelog but Cineform Raw also comes at a price.

You obviously have no grasp of the intended use of Cinelog or those who will use it. As I also said in my reply we do have several professional users (DITs, colorists and DPs) who do know their subject and likely understand a considerable amount more than you.

Not everyone is comfortable working in Resolve but Resolve Lite (which is FREE) can be utilized to debayer and render much faster than ACR meaning you can work with the next best thing to the raw DNGs in an EFFICIENT codec in whatever NLE you choose and usually in realtime on a lower spec system.

No we can't presently do anything about debayering in Resolve but we have a fully featured DIT app coming that will ;)

To insinuate that our work is there purely to make money from users who do not poses certain knowledge or skills is highly ignorant, insulting to our customers and bordering on slander! Just because you have a system that works for YOU does not mean it will work for everyone else. The same can be said of what we offer but oddly enough, as I pointed out in my reply to you, our customers which includes professionals are satisfied with what we offer.

I suggest you look beyond your own blinkered view and 'post-production' environment and understand that there is in fact a big demand for what we offer, just as there is for what VisionLog and others offer. Why do you think ARRI, Sony, Canon, Blackmagic, Red (I could go on) have Log gamma recording in their raw capable cameras? WE cannot record to 10bit ProRes HQ with a log profile in-camera but I can tell you one thing. It's probably the #1 feature request in DSLRs and just as with most DPs who shoot on the big cameras MOST WILL SHOOT LOG encoded ProRes or DNxHD (some even record to Cineform ;) ). While we cant record compressed in-camera we can do it in post in a controlled way (exposure, white balance happens BEFORE the Log transform) and have all the space and timesaving benefits of log encoded media. No it's not 14bit raw anymore but it grades very nicely :) plus you can store the files easily! Oh, did I mention realtime playback, no need for proxies, easy set-up an rendering and technical support?  :)


Oh, just saw your comments about LR and DaVinci Resolve - That says a lot ;)

Have a nice evening.



 

 
Colorist working with Davinci Resolve, Baselight, Nuke, After Effects & Premier Pro. Occasional Sunday afternoon DOP. Developer of Cinelog-C Colorspace Management and LUTs - www.cinelogdcp.com

tjaja

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #133 on: April 21, 2014, 08:05:15 PM »
Discussion breaker. Case closed. I like colors. Do you? Wait, what?
5DFree, 550D, canon 50mm 1.4

Andy600

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #134 on: April 21, 2014, 08:06:48 PM »
Discussion breaker. Case closed. I like colors. Do you? Wait, what?

 8)
Colorist working with Davinci Resolve, Baselight, Nuke, After Effects & Premier Pro. Occasional Sunday afternoon DOP. Developer of Cinelog-C Colorspace Management and LUTs - www.cinelogdcp.com

CF

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #135 on: April 21, 2014, 08:18:08 PM »
Andy, I was not insinuating anything. I was being straight forward in my writing. I don't think that I said that your product wasn't going to provide anyone with results. I got involved in this thread as per what I wrote in my posts... " true log space conversion" etc etc etc...

If anyone was insinuating anything, it was that you ;-)


I use SG for real-time Debayering on rMBP with a fast SSD. Resolve gets me 12 frames per second. SG a WHOLE lot more. I don't need more than the rMBP. I work with cDNG Directly and archive in PR4444.
Would never use Cineform. Never had any good experience with that codec or software.

Anyway.... Nice evening to you to  :)

DavidSh

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #136 on: April 21, 2014, 08:23:27 PM »
I personally love Speedgrade and the way it handles RAW. It serves me the images as Linear as they are. All green, very ugly and extremely unusable, initially. However, I can do ANYTHING to them that I want - a developers dream. And I don't need to work against any Lightroom, Da Vinci Resolve Linearization Curves. It is easier to apply to a linear RAW, the amount of Gamma or whatever one needs than to try and take it off those auto-pilot algorithms. Resolve to me is like Lightroom - Automatic as H*** and I don't like that. SG (I am NOT working for adobe) is IMO the most fantastic software I have ever used.
Weird and ugly interface, almost no documentation but with a POWER and potential that no other app has ;-)

So if anyone wants to learn, get a premature heart attack, get unprecedented development possibilities and have fun all at the same time, try Speedgrade ;-)
:-)
Thank you for that...
why is that ugly green? and what is the best way to get rid off? (when i use direct link from premiere its not there...)
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CF

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #137 on: April 21, 2014, 08:39:46 PM »
:-)
Thank you for that...
why is that ugly green? and what is the best way to get rid off? (when i use direct link from premiere its not there...)

No clue about the green. My best bet is that SG is not reading the metadata of the RAW cDNG. In PPRO the the image is Magenta and has a 2.2 Gamma curve applied to it as well, to make things even more complicated. Green and Magenta is basically the same, or should I say opposite thing ;-)

I've been beta testing a SG Plug-In dealing with this. If and when it's up for public release, I don't know !

50Deezil

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #138 on: April 21, 2014, 08:53:16 PM »
MEH!!!  I have a low level of technical knowledge about this subject.  I bought Cinelog because I needed a low cost, low CPU/GPU/Storage overhead, Easy to use workflow.  I wanted great results and from everything I saw this product could help get to great results for a relative noob like me.  I don't care about what seems to me to be an argument over semantics or purist techno babble.  For me workflow and end results are everything.

Andy600

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #139 on: April 21, 2014, 08:56:36 PM »
No clue about the green. My best bet is that SG is not reading the metadata of the RAW cDNG. In PPRO the the image is Magenta and has a 2.2 Gamma curve applied to it as well, to make things even more complicated. Green and Magenta is basically the same, or should I say opposite thing ;-)

I've been beta testing a SG Plug-In dealing with this. If and when it's up for public release, I don't know !

Maybe something to do with BayerGreenSplit or lack off in the DNG tag?
Colorist working with Davinci Resolve, Baselight, Nuke, After Effects & Premier Pro. Occasional Sunday afternoon DOP. Developer of Cinelog-C Colorspace Management and LUTs - www.cinelogdcp.com

CF

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #140 on: April 21, 2014, 09:08:12 PM »
Maybe something to do with BayerGreenSplit or lack off in the DNG tag?


I've tried changing the EXIF Tags... SG doesn't care one Bit ;-)

iaremrsir

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #141 on: April 21, 2014, 09:09:59 PM »
Maybe something to do with BayerGreenSplit or lack off in the DNG tag?

No, SG just doesn't read the matrix even if the tags are there. It requires you to input it or the raw white balance values.

DavidSh

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #142 on: April 21, 2014, 09:30:49 PM »
No, SG just doesn't read the matrix even if the tags are there. It requires you to input it or the raw white balance values.
So why it does not do that when you open it using direct link from premiere?
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iaremrsir

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #143 on: April 21, 2014, 09:53:17 PM »
So why it does not do that when you open it using direct link from premiere?

Because Direct Link uses Premiere's debayer settings for all file formats. That's why the SpeedGrade app as a copy of all of the Premiere Pro importer plugins and effects.

reddeercity

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #144 on: April 22, 2014, 12:02:34 AM »
Because Direct Link uses Premiere's debayer settings for all file formats. That's why the SpeedGrade app as a copy of all of the Premiere Pro importer plugins and effects.
Read this, it will fix that green cast in SG. (Need to load a .look file with values for the colormatrix ) Its because the black level has been change for Cdng in Premiere Pro without any pink cast at 16bit Cdng
http://www.magiclantern.fm/forum/index.php?topic=5618.msg111704#msg111704

iaremrsir

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #145 on: April 22, 2014, 02:55:44 AM »
Read this, it will fix that green cast in SG. (Need to load a .look file with values for the colormatrix ) Its because the black level has been change for Cdng in Premiere Pro without any pink cast at 16bit Cdng
http://www.magiclantern.fm/forum/index.php?topic=5618.msg111704#msg111704

I know this already, but the point I was trying to make for him was that SG doesn't actually use its own demosaic and color transforms for footage when in Direct Link with Premiere.

reddeercity

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #146 on: April 22, 2014, 04:44:44 AM »
Ok got it  ;)

kardolan

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #147 on: April 26, 2014, 10:10:16 PM »
Just converted my RAW footage via the ACR -> Cinelog -> DxHD 444 process and it looks like it's a killer combo :)
The only thing that is a bit annoying is the time for processing and exporting that is way slower than the Resolve.

Come back to post some graded results to you guys as soon as I've finished the editing and my current job ;)

mixmastermike

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #148 on: April 26, 2014, 10:21:26 PM »
Just converted my RAW footage via the ACR -> Cinelog -> DxHD 444 process and it looks like it's a killer combo :)
The only thing that is a bit annoying is the time for processing and exporting that is way slower than the Resolve.

Come back to post some graded results to you guys as soon as I've finished the editing and my current job ;)

Id love to see some actual video clips of the results of this process, so thanks in advance!

Jbowdach

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Re: Cinelog - True logspace conversion for DNG and CinemaDNG footage
« Reply #149 on: April 27, 2014, 06:20:05 AM »
Hi All, slightly new to ML Raw but not new to log grading, but I had a few questions about ML specifics.  From what Im reading, it appears the ACR route is still better than Resolve but WAY slower? I ask because I just bought the Resolve version and I was wondering if it was too late to be included in the group that received the ACFR version as well? Many thanks!

Im shooting on a 7d raw. Thanks for your help!