Cinelog - True logspace conversion for DNG and CinemaDNG footage

Started by Andy600, January 24, 2014, 06:05:11 PM

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DeafEyeJedi

Thanks @Andy600 for your deep depth explanation regarding the workflows w your LUTS. Looking forward to testing them out this weekend when I get back from work on the road!
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

Jbowdach

I forgot to mention Im using Davini Resolve, not AE version. Hence I have a HUGE mess of Cinelog LUTs in my Resolve folder. Could you please advise how to combine the update w the Resolve version so I can easily jump through the 5 different types of LUTs w/o having so many different file naming schemes , etc?

Essentially, is may be easier if you could provide the entire package as one instead of an update? Or at least if you could advise regarding which LUTs can be combined within the previous 5 folders in the v3 folder structure (unless it really requires a 6th folder).

Just trying to make this easier to use during a fast paced grading session and my cinelog folders are a mess. Many thanks and looking forward to more in the LUT bank.

Invested in both versions earlier, but would love to support the ACR version as well. Would you happen to have a coupon for those who already have purchase \ supported the project? I think it would be a great addition to my toolkit aside from having it in Resolve.

Many thanks!!

Kharak

I am very interested in the ACR version as I find ACR's debayering to be superior to all the others.

What I've noticed with VisionLog is that Shadows could be raised more and aswell Highlights could be lowered more.. But ofcourse when I do that I introduce flicker if highlights or colours are changing too much.. But still I always raise shadows to see if I can get away, flicker free..

Raising shadows when using VisionLog might introduce some noise, but the "information"-gained-to-noise-ratio is totally worth it and I have always been sucessful with removing the noise so that I have achieved more DR in shadows without having noise ruining the shot.

Would be nice with a screenshot of Cinelog and Visionlog side by side comparison. If shadows are raised more in Cinelog, you got yourself a new customer.
once you go raw you never go back

Andy600

@jbowdach - Cinelog-C replaces all previous versions including the pre-release. Previously we hadn't fully worked out a reliable method for building the colorspace transforms into shaper luts. Colorspace transforms must be fully invertible and transferable. The new [Transform] luts are just that.

The Display Transform luts are also colorspace transforms but include the output transform associated with each colorspace (i.e. ProPhoto with it's 1.8 gamma transfer curve).

The REC709 and Film Look luts are built specifically for Cinelog-C colorspace.

I'll PM you :)
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

Andy600

@Kharak - With Cinelog you do not touch the highlight and shadow controls in ACR. The only things you adjust (if needed) is white balance and exposure offset. Noise reduction and sharpening are optional.

The VisionLog curve is a bit odd and has flat spots so it's likely it's not based entirely on a formula. The Cinelog v3.0 transfer curve is a precise log formula including an offset to compensate for ACR display gamma plus it's hard coded to 12bit values (i.e. better than actually needed).

The only function of these curves is to get the signal from ACR to the host (After Effects) without clipping and with as little manipulation as possible. Ideally, a scene linear DCP profile would be best but this would certainly clip the signal during the transfer between ACR and AE (linear in ACR is basically sRGB with 0.454545 gamma offset and not the same thing as scene linear). A log curve should not ordinarily have any flat spots (especially in the mid tones). The only flat spot that may be in a log curve is a tiny linear (straight line) portion at the low end to minimize sensor noise.

I will post an A/B between Cinelog V3.0 and VisionLog but it wont really tell you anything. The critical bit is accurate inversion of the curve to scene linear values to restore every F-stop. Cinelog v3.0 will store ~13.5 F-Stops and passes the data from ACR to AE without any clipping. There is a lot of scope for manipulating the shadows and highlights when it comes to grading. The transform from Cinelog V3.0 to Cinelog-C in After Effects is there to ensure all pixel values fit within a 10bit container so you can export a log master (ProRes /DNxHD) containing all the data.

Edit: http://we.tl/2hB6hxkceO This shot is pushing the DR of a 50D to the max. The lights were clipped slightly when it was shot. Images show the curves and how both profiles appear in AE with identical settings plus how Cinelog V3.0 looks when it's transformed to Cinelog-C wide gamut. Check out the highlight detail ;)
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

Kharak

Yes ofcourse, what I meant by my post was that I hope I don't have to raise shadows/lower highlights with Cinelog, like I always feel the need to do with Vision log. Because (I feel) Vision log does not utilize it's curve properly. And thereby introducing the possibility of flicker depending on the scene as I always raise the shadows with Visionlog (if it does not introduce any noticeable flicker)

And even when using the impulz luts with visionlog profile I still get better results if I tamper with Shadows and highlights.. Or to be more frank, I get better looking results and higher DR. Which is weird as its from the same developer.

tampering with shadows/highlights works against your transformations, I totally understand that. What I want most of all is a Log image out of ACR without flicker, preferably with more DR than what Visionlog offers. If I knew how, I would change the parameters of visionlog to increase shadow gain and have highlights lowered, but I am sure its not as simple as that.. Alas, I want it bad enough that I would pay for it.

Thanks for taking the time for making a detailed reply to me. I can't look at the link at the moment, I am on a phone.
once you go raw you never go back

baldavenger

I'm still becoming familiar with the recent updates, but I just want to add what a great job you've done in making the MLV workflow a more viable and professional one.  I look forward to the upcoming additions to the tutorial section and LUT Bank  :)
EOS 5D Mark III | EOS 600D | Canon 24-105mm f4L | Canon 70-200mm f2.8L IS II | Canon 50mm f1.4 | Samyang 14mm T3.1 | Opteka 8mm f3.5

DeafEyeJedi

This is definitely good to know!

+1 @Andy600

;D

p.s. I just got back from a week long road-trip for work and will get myself started on the testings w your new LUT's.

although I got a question (maybe its already been answered) but do I use a Cinestyle (from Technicolor) to use as a color profile in the 5D3 or would you suggest a different FLAT neutral version?

*cheers*
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

baldavenger

Unless you're recording h264, the in camera profiles will have no effect on your recorded files.  They may act as a visual reference on your LCD screen or external monitor when recording raw files, and that reference can carry on if the profile is selected in ACR, but if you want to use cinelog then you would choose that profile instead.  It's more a matter of exposing correctly, though Andy probably has specific advice with regards to exposing for cinelog.
EOS 5D Mark III | EOS 600D | Canon 24-105mm f4L | Canon 70-200mm f2.8L IS II | Canon 50mm f1.4 | Samyang 14mm T3.1 | Opteka 8mm f3.5

Andy600

Yes, the in-camera Picture Style has absolutely no connection with MLV.

Pictures Styles are referenced in the metadata of raw stills and baked into H.264 but completely omitted for raw video so it doesn't matter what you use. For me personally, I tend to use Canon's Video-X Picture Style (with the contrast dialed down to 2) just for a visual reference - why? no particular reason.

I don't have a 'golden rule' for exposure and I tend to assess every scene differently using the raw exposure aids - not my eyes. Exposure techniques used in photography apply equally to raw video and lighting is always the most important factor.

It's far more important to make proper use of the raw exposure aids when recording MLV. I always have raw zebras and ETTR hint enabled.

ETTR is great for better signal to noise ratio but it's not ideal for everything.

If it's a difficult, low ambient light scene but has areas of intense point lighting (for instance, a car's headlights), ETTR will mean you are effectively exposing for the car's headlights (as that is the brightest thing in the scene and the thing that raw metering will reference) - thus pushing the important elements into noisy under-exposure.

You will often need to clip more of the highlight information (specular highlights and things that emit light such as headlights, neon signs etc) than you think to get good exposure of the main subject (actor, product etc). How much you need to clip depends on the camera, lens and subject lighting.


I make adjustments to ISO depending on the lighting conditions (lower ISO for well lit scenes and higher ISO for low light) and set the aperture depending on the depth of field (DOF) I want to achieve (but not always possible). The DOF is always dictated by the lens aperture, the maximum useable ISO of my camera and, most importantly, the lighting conditions. I then frame and focus the shot before hitting record

but..

If I'm shooting MLV on my old 50D, I know that the maximum useable ISO is 800 before noise becomes too much of an issue. If I use my widest lens (F1.4 50mm) I know it is too soft at maximum aperture so the widest I can go is F2.0. If I do not have control over scene lighting, these 2 things limit what I can hope to achieve with that camera and lens combination. If I can't get a good exposure within these limits I simply don't hit record.

When it comes to dynamic range you also have to remember this:

The lower the ambient/available light is = the wider the lens aperture needs to be + the higher the ISO you must use.

As you increase the ISO you decrease the maximum dynamic range of the light being captured/recorded and as you open the aperture wider it will also decrease the DOF. What this means is that sometimes you just cannot hope to get the shot in the way you envisaged, or even not at all. The available lighting and your equipment (or lack of) will limit what you can hope to achieve. It's technology and physics.

Canon DSLRs, in optimum lighting conditions can capture ~11 F-stops (scene linear) but this only applies to optimal lighting conditions. In reality it's more like 8-10 F-stops at best. A wide, establishing shot of a night time city scene, with a mix of very dark areas (alleyways, unlit shop interiors etc) and very bright areas (street lights, illuminated shop windows and car headlights) can exceed 15-20 F-stops so you, as the DOP, must choose what it is that is most important for the audience to see and expose for that.
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

DeafEyeJedi

I knew that the picture profiles really have no affect to the RAW/MLV recordings but I guess I should have been more clear with my previous question -- would it be more helpful to use a modified picture profiles in camera to give you the idea of what it MAY look like once finalIzed in color grade.

Basically like how some SmallHD monitors can do with MONITOR LUT's but without that and somehow manage to get it close to that on the LCD within the DSLR's.

However, I appreciate your eagerness in typing down extreme details that can be useful for me and others to keep in mind when it comes to exposing properly.

Coming from a photography background definitely helps me with the understanding of how to read the Histogram (RGB) and sometimes using the ETTR can affect my shots differently (not always) so it really depends on the situation just like you mentioned above.

I'm still narrowing down my testing with the new Cinelog LUTS...

Any new updates in the LUT bank as of yet?

Thanks again @Andy600 for your kind business, as always!
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

arrinkiiii

Hi Andy,

For the last days im trying the new version of Cinelog 3.0 and i come to a sequence of DNG's that i can't see in ACR, Camera Profile the Cinelog option. I think is because of my DNG's.  This is the link for one DNG for see if you can see whats happen. Thanks =)


https://www.dropbox.com/s/0snd985ty0qh4uf/M10-1938_000000.dng?dl=0


DeafEyeJedi

5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

arrinkiiii


Hi DeafEyeJedi,

I use MlRviewer... but the last versions didn't read my RAW file, so i have to use 1.3.3 version for read this file. I think is because is a RAW file and don't have metadata... and in ACR he don't have enough information for see what camera is, etc...  (7D)  I got like 20 files like this and would to like to use the cinelog profile/curve.

Thanks for the help =)


Andy600

@arrinkiii - What app did you use to convert/extract this DNG? and what camera is it?

The metadata is wrong (in several places) and it doesn't have the correct UniqueCameraModel tag for your camera - it just says Canon EOS (No camera uses this name!). You can fix this using Exiftool but if all of the images that you are having issues with were converted with the same app I can send you a custom .dcp that will read them in ACR - I just need to know the camera model they were shot on.

The color from these images will be probably be wrong in Resolve - If you use Resolve you will definitely need to fix the metadata with Exiftool.

I suggest to anyone who extracts DNG from MLV files to do the following:

Mac users should only use MLVFS and Windows users should only use raw2cdng

Because, at present, they are the only 2 apps that currently embed the correct matix metadata (unique to each camera model).
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

Andy600

@DeafEyeJedi (still love the name  :D)

Creating accurate Picture Styles that mimic what a specific LUT does is a pain in the a**. Ideally we could just translate the actual LUTs we make to Canon's Picture Style format but that's near on impossible with the tools available. We have thought about creating some Filmic Picture Styles (not log) for H.264/Jpeg based on the characteristics of certain Film Stocks but I can't say when or even if it will ever happen. It depends on what time I have and at preset all my time is devoted to adding LUT Bank content.

If you login to the LUT bank you will see the updates/additions scheduled for release this week. The new Quick Start guide for Cinelog-C (Resolve version) will be online in a couple of hours.

While writing the guide it made me think of a few important gotchas regarding MLV metadata. These really need documenting, so sometime in the next week I will write another article - It will not be limited to LUT bank members as it affects all Magic Lantern /MLV users.
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

DeafEyeJedi

@arrinkiiii -- as much as I love @baldand's MLRawViewer (I still use it) but prefer to use @dmiligan's MLVFS w Cinelogs.

@andy600 -- Thanks! Figured. Makes sense regarding Picture Styles. Not that important atm but sure can be useful for lazy people like me. lol. Will definitely check out the updates/additions frequently when I can.

Looking forward to your article and much appreciated for your work-ethics, Andy!
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

arrinkiiii

Thanks Andy and DeafEyeJedi for the help =)


Im using ACR on Windows 7 (64) with MLRawViewer. MLVFS on my windows machine don't work good, unfortunately.

Yes,  all of the images that im having issues with were converted with the same app. It would awesome if you can send me a custom .dcp for the ACR read them, my camera is a 7D.


Other question regarding the workflow whit ACR-AE-OpenColorIO
   
           -For example:  I use in ACR the Cinelog 3.0, them i close it and put one OpenColorIO in the file. Do i need to chose the input with Cinelog 3.0 (ACR)  and output Cinelog and them open other OpenColorIO and chose custom and chose a LUT from your bank or, since that in ACR i already chose the Cinelog profile, i can just open one OpenColorIO and chose costum and chose my LUT from the bank?


Andy600

@arrinkiiii

Can you PM your email address so I can send you the custom profile?

I'm not sure I fully understand your question but the basic workflow with the Film Look LUTs would be:

1. Starting in After Effects - Import your image sequence - This opens ACR
2. Select the Cinelog V3.0 profile, click OK to go back to After Effects
3. right+click on the imported file, select Interpret footage and change the frame rate, click OK
4. Add the file to your timeline (or create a new comp, 32bit/REC709)
5. Add the OpenColorIO plugin (found in effects/utilities)
6. Select the Cinelog-C config in the plugin
7. Choose Cinelog V3.0 as the Input Space and Cinelog-C as the Output space
8. Add another OpenColorIO plugin but this time choose Custom from the drop down menu - this will open the browser.
9. Choose a Look Lut

If you have Look Luts for a different colorspace (i.e. Impulz for Log-C) you would choose Alexa Wide Gamut Log-C EI800 as the Output space instead of Cinelog-C and load the Impulz lut in the second OCIO plugin

If you have some non-raw Log footage (i.e. Slog from a Sony camera, Canon Log from the C300, Log-C from the Alexa or Amira etc) and want to use the Cinelog Film Looks, just choose the colorspace of the Log footage as the Input space and Cinelog-C as the Output space, then choose the Film lut in the second OCIO plugin.

You don't need to use the OCIO plugin for hosting LUTs but it has better interpolation than the native After Effects LUT plugin.

If you want to use MLRawViewer (which can apply several Log options), you should remember that all MLRV Log options use REC709 primaries and white point. MLRV does not target the full colorspace (i.e. it only does 1D linear to log transforms) and will not work with the Cinelog-C OpenColorIO config or Cinelog Look Luts at present.
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

swinxx

hello @andy600
i just study your tutorial for davinci resolve and wonder why my use video monitor selection for scope the video monitor output not the timeline output is set to gray in the options menu.. is this only for the full resolve version?
greets swinxx


Andy600

Hi Swinxx,

Glad you worked it out! Everything in the Guide relates to both the free (Lite) and paid versions of DaVinci Resolve. I know most users will probably be using the Lite version.

The workflow I describe is deliberate so that what you see is REC709 but what you render is Cinelog-C. There are a multitude of other workflows but I wanted to start the Guide with one that demonstrates a simple transcoding workflow to give you log files and also show some of the versatility of Resolve's lut management. We will cover some of the other methods in future guides.

If you ever think something is not explained well please do let me know. I'm not precious about my tutorial writing skills :)
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

swinxx

very nice explained andy.. thank you.
i always denoise before i make any lut transforms but you can not do that in the lite version without 3rd party plugins like neat ofx..
however. well done. i will try out.
the problem which i always have is, that all the dslrs have problems with green gras.. most of the time that green looks just awful..
greet.s

DanHaag

In the LUT bank "Print Emulation LUTs for Cinelog-C pack 01" and "Film Looks for Cinelog-C - Pack 1" have the same archive file name and seem to contain the same LUTs. Or are they in some way different but just labeled identically?  ???

Andy600

@DanHaag - Thanks for letting me know. The link is now fixed.

@swinxx - Thanks. For better grass try some of the film looks. This is something we can look at addressing in a tutorial so I'll add it to the list.
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