Cinelog - True logspace conversion for DNG and CinemaDNG footage

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

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Andy600

Hi @Rodrigo - Sorry for not getting back to you immediately. We're based in Europe and it's out of office hours but I still try to check emails during the evening.

Your issue is related to the camera ID tag and is caused by either using raw_rec or an old converter. We recommend using MLV_rec and using either MLVFS or raw2cdng to extract the DNG files and write the correct metadata.

The metadata can be fixed using ExifTool (or simply reconvert your raw files with MLVFS or raw2cdng) but to save you the hassle I will send you a profile for the generic tag shown in your DNG - The profile will be accessible to any DNG with the Canikon tag but it is important that it only be used with the 5D mark II due to camera specific matrices. Please check your email in a few minutes.
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

Rodrigo Riedel

Hi Andy600,
Thank you, I was converting using raw2dng and the profile wasn't showing up. I then used RAWmagic and it worked out just fine

Rodrigo Riedel

I'm on a mac so raw2cdng will not work...onless they have a .dmg for mac users

Andy600

@Rodrigo - No problem. I've just sent you the generic profile should you have older DNGs without the original raw container. Also a direct link for LUT Bank registration.

raw2cdng is PC only but MLVFS is Mac :)

Best regards!
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

Rodrigo Riedel

Hello Andy600,
thank very much. Now will this profile that you just sent me will work like the purchased ones that I just got? I ask this because for some reason RAWmagic is giving me ALL pink washed out frame ( no idea why ).

Also, is it possible to get the CANIKON profile for the T3i as well, I use that one just as much as the 5D mark2

Thank you

Rodrigo

DeafEyeJedi

I'm afraid as many of us stated before -- RAWMagic isn't supported here on ML. (Regardless of how nice the app may seem)
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

Rodrigo Riedel

@andy600- Hi again ( sorry to be such a pest ). If you cannot send me the CANIKON profile for the T3i, how exactly can I use Exiftools to recover the metadata in my dngs.

Thanks again

Rodrigo

kontrakatze

Maybe I'm a little off track (due to my flu  :-\), but if I import some dng into Resolve using BMD to Cinelog-C as an input lut and later on Cinelog-C to BMD (round trip, I know, it sounds stupid), shouldn't the clip look the same like completely without luts? Which it doesn't in my case, frankly speaking they look crazy.

I came up with this by just playing around with filmconvert pro for resolve. I tried to find the best way to send filmconvert the data (choosing camera and profile), so I tried a lot of combinations using the transform luts. Arri Alexa with rec709 is a nice starting point, but I wanted to know if there is something better...

Regards

Andy600

@kontrakatze - I'm not sure what you are doing but the Cinelog-C to BMD Film lut is an exact inversion of the BMD Film to Cinelog-C lut. You can test this easily by adding 2 nodes. On the first node, add the BMD Film to Cinelog-C lut and on the second, add the Cinelog-C to BMD Film lut. By pass all nodes (Alt +D from memory) and the image will not change.

re: Film Convert - Cinelog-C is the same as Log-C Wide gamut RGB but has a slightly different log curve (less compressed) - the Film Convert Alexa presets will be the most accurate but remember, the color of your DNG's is defined by the color matrices. You could also try the Cinelog-C to Cinelog-C with Film Matrix lut before adding an Alexa Film Convert preset.
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

kontrakatze

Ok, I found the reason for this error. Somehow Resolve did not update the preview correctly. I had to switch do the second clip and back to the first clip for the update to take place. Therefore the weird look. By the way, I changed the input-lut in the preferences.

Regarding filmconvert, I'm still not sure which way to take:

- importing dng to resolve
- setting expo and white balance
- transcoding to cinelog-c, exporting as prores

- importing prores files  again (I sometimes take Prores 4444, sometimes just ProresHQ)
- color correction
- and now what? On the last node before filmconvert: "Cinelog-C_to_Alexa_Log-C_EI800_with_Film_Matrix" or "Cinelog-C_to_Cinelog-C_Film_Matrix_RGB" to get the color matrix to filmconvert? And as a camera what do I choose? Arri and LogC / LogCFilm for the first instance,  Default and sRGB for the second instance?
- What do I get from filmconvert? Is this still Cinelog-C after the filmconvert node? Is this dependant on the Camera I chose? In this case LogC for the first one and sRGB for the second? Do I have to put a Cinelog-C to REC709 on the output?


And one last question:
The difference between "Cinelog-C to REC709 Full" and "Cinelog-C to REC709 Legal" is quite clear, but how does "Cinelog-C to Cinelog REC709" come into the game? I thought Cinelog and Rec709 are quite different colorspaces?

As I have to stay in bed, I have time to think and get confused...

I hope I don't step on anybodies nerves....
Regards



Andy600

Yes, you pretty much have the procedure right but you would add the "Cinelog-C_to_Alexa_Log-C_EI800_with_Film_Matrix" or "Cinelog-C_to_Cinelog-C_Film_Matrix_RGB" before your color correction i.e. the node chain to add to your imported ProRes log masters would be:

1. Cinelog-C_to_Alexa_Log-C_EI800_with_Film_Matrix or Cinelog-C_to_Cinelog-C_Film_Matrix_RGB (this transforms Cinelog-C to Alexa Log-C with either Alexa Wide gamut or Alexa Film Matrix primaries)

2. node(s) for color correction/grading - (leave untouched for now)

3. Film Convert - select Alexa Log-C or Alexa Log-C Film Matrix (depending on which profile you used in step 1 above)

4. Use the Film Convert curve control to adjust contrast and sat control for saturation

5. make changes to color using the node(s) added in step 2 or just use the Film Convert controls

6. check levels on scopes and export your graded video.

Alternatively, select any other Cinelog-C to 'other colorspace' lut and use the relevant Film Convert input profile. i.e. Cinelog-C to sRGB lut and Film Convert's default sRGB input profile.

Film Convert is emulating what the image will look like if it were to be printed to film using an ARRI laser http://www.arri.com/archive_technologies/arrilaser/ or similar. The one step I am not sure about with Film Convert is what (if any) Color Print Stock or color reversal film they emulate!?

In a real film workflow the image would be captured on film negative, the negative would be developed and this would then be printed to a color reversal film, color timed (i.e. a primary grade using printer lights) and printed to a color print film master (i.e. Kodak Vision 2383 etc). This is then duplicated for distribution.

If Film Convert does not include the last step (i.e. the Color Print Film) you will need to add a good PFE lut (Print Film Emulation) and set Film Convert's Film Curve to zero (i.e. so you only get the color and not the contrast).

Depending on the Film stock emulation selected and print emulation lut you may get very thick or sometimes out-of-gamut color that will require color correction in nodes before the Print Emulation lut. This is exactly the reason PFE luts exist i.e. so you can avoid any nasty surprises when your digitally captured video is printed to real film - it allows you to see color errors and correct them before committing to expensive printing.

The Cinelog-C Film Look luts do everything in a single lut  ;) - we have added corrections to adjust for possible color errors, added saturation and other color tweaks for the 'look' and use the gamma/tone curve of the print stock for contrast - but because we added saturation and color tweaks/fixes we don't call them PFE luts.

re: your last question: yes, Cinelog-C and REC709 are very different. Cinelog-C is a scene referred colorspace and REC709 is a display referred colorspace. The Cinelog-C to Cinelog REC709 (legal and full range) luts are based on the REC709 transfer function and all Cinelog-C to rec709 luts transform from Cinelog-C primaries to REC709/sRGB primaries AND the include our s-curve to fit the DR of the image into a REC709 display space.

The Cinelog-C to REC709 lut is the same but does not have an s-curve (i.e. it's just the rec709 transfer function) and highlights will clip. The rec709 transfer function will allow for highlights above 1.0 (floating point) up to ~2.2 (on a scale of 0.0 - 1.0) but any values above 1 will be clipped when rendered - this is what an s-curve is for  ;)

Get well soon!!  :)
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

kontrakatze

Andy, what shall I say, you are damn great!

Thank you very much, I think I got it know. This IS complicated and there are quite a lot of big stones on the way.
While coffing like a wulf I had some good time reading  ;D , but I'm getting better day by day.

Kind regards,
kontrakatze

kontrakatze

@Andy600: i talked to the people at filmconvert. They told me whatever you put into filmconvert the output is sRGB. What would you recommend to do to get a Rec709 in the end? What can I do to transform sRGB back to Cinelog or directly to Rec709? Any ideas? 


Regards

Andy600

@kontrakatze - sRGB and Rec709 use the same RGB primaries. The only difference is that sRGB is a 2.2 gamma power law curve and Rec709 has a small linear part to help suppress sensor noise. Rec709 shadows are subsequently a little darker but the color will not change and gamma is ~2.4. I'll upload an sRGB to Rec709 lut for you (check PMs in a min).

There is no need to transform to Cinelog-C again. If you want to add a PFE lut just set Film Convert's curve to zero - your image will have the film preset's color but still be print density. Print Density is required for PFE luts ;)
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

kontrakatze

Andy, thank you very much! This was a big help!


Have a nice day,
kontrakatze

TrueIndigo

Andy I was wondering what your recommendations are for output format? I was reading up about the ProRes codecs, which seem like a good choice to master from the ML DNGs, but since I use Windows/Adobe, I assume I can't export from After Effects/Cinelog to ProRes because there is no ProRes encoding on Windows? I have used DNxHD in the past, but I was wondering how to set non-16:9 frame ratios (such as 2.39:1) or frames bigger than 1080. And it seemed a bit strange to use as if there was a bug (for example, the dialogue box appears slightly off the top of the screen and the field box in it dips below the dialogue boundary itself). I see there's now NDxHDR which perhaps is better?

Andy600

@kontrakatze - You're welcome! :)

@TrueIndigo - You can get 3rd party ProRes codecs like http://www.miraizon.com/products/codecsoverview.html for Windows but they are not identical to Apple ProRes and have been known to fail broadcast standards tests.

I personally stick to (and recommend) DNxHD for most things on a Windows system.

I haven't experimented enough with the DNxHR codec in Resolve. AFAIK it can only be used if wrapped in an MFX container - some NLE's don't support MXF. It's nice to have UHD output and there are variants that seem a like-for-like match of ProRes (i.e. hq, xq, 4444 etc) but I can't recommend using it with Cinelog unless you are sure your NLE can read MXF and DNxHR.

DNxHD and DNxHR output in fixed 16:9 or 4:3 frame ratios. You will always get black bars if your footage is not the same. Most domestic displays use those ratios and AVID decided to go with the standard. I also think it's a bit inflexible for an intermediate codec, but it's not a bug. You can always re-frame/crop the final video dimensions when rendering your deliverable (i.e. H.264, DCP etc) but remember, any grading you do to your Cinelog-C log master will also affect the appearance of the black bars. You can get around this using Resolve's Output Blanking.

There are several other codec options you could try such as Cineform 10bit/16bit, Grass Valley HQ/HQX or plain old .DPX image sequences (still a favorite among colorists) but the main thing to remember when rendering a Cinelog-C log master is to always render to 10bit or higher bit depth codec.
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

Lars Steenhoff

Hi Andy will you put the conversion puts from srgb to rec709 to the LUT bank?

Andy600

@Lars - Yes, I'll add that one now plus there are a few other REC709 and Film luts to add today/tomorrow. I'm preparing a update mailout with a few more transforms - ACES 2065-1, ACEScc, ACEScg and updated ACES Proxy plus 'beta' transforms for Cinestyle, ProTune Flat, Protune Rec709, ProLost Flat. There is also a transform specifically for Canon C100 and C300 cameras (shooting Canon Log in CP Lock mode), built using ACES - this is so we can test a specific camera IDT outside of an ACES environment.
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

beauchampy

Fantastic! Cannot wait to try the ProLost and Cinestyle transforms!

Danne

@Andy600! Massive thanks for you,re awesome cr2hdr dualiso log lut. I just published the latest update for cr2hdr-r. The results are beautiful.
http://www.magiclantern.fm/forum/index.php?topic=13512.msg140964#msg140964

DeafEyeJedi

*drooling* like a dog in here... Quit teasin' me @Danne!

Looking forward to your new LUTS in the bank @Andy600!

P.s. I shoot often with CineStyle On 5D3 for work (when MLV/RAW isn't permitted) shame on my bosses! [emoji6]
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

baldavenger

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

ruber

Hi @Andy600 and guys

I followed your tips and I am converting in Resolve my dng clips into DNxHD.
But I have a gamma shift issue during one of the steps of my workflow.

My workflow:
- convert MLV to Dng with raw2cdng
- open my clips in resolve in a timeline
- white balance
- in the first node, apply the transform lut "bmd to cinelog" (I did not do it in the input panel and now I have too many clips already done... )
- render as individual DNxHD 1080p 444 clips

now, I have my clips ready to edit in Premiere:
- import DNxHD 1080p 444 clips in premiere
- edit
- send to resolve with fcp xml
- apply in the last node cinelog to rec709 legal LUT (as above, I should have put the LUT in the output voice in the panel)
- Color correct in the nodes before the lut


Now, it comes the issue:
Since I need to apply lower thirds and graphics to my final Color graded clip, I want to send it back to Premiere, so:
- render as unique DNxHD 1080p 444 graded clip
- import into premiere
- apply graphics etc
- render as h264

And the problems are:
- When importing in premiere, the grade is slightly washed (comparing with the result I see in resolve), like there is some gamma issue.
- When I render as h264 from Premiere, the clip is even more washed than what I see in premiere.

I checked rendering directly in resolve a h264 clip and the result is perfect, exactly what I see in resolve as well.
But this way I cannot have my lower thirds, nor my preffered transition effects I apply in Premiere...

I don't know if this is the right place, but since you reccomended to render our clips in DNxHD and keep them and discard MLV, maybe you already know how to handle this.

Thank you. Regards.

Andy600

@ruber - this is related to the way premier handles full range levels with some codecs/wrappers.

On your second pass (the graded, edited footage) try exporting a DNxHD 444 shot with Video levels instead of Data levels (in the render job settings panel of Resolve).

I'll also add a couple of technical luts to the LUT Bank for 'data_to_video' and 'video_to_data' corrections.
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