Author Topic: Gamma Shift in Quicktime 7 Pro Image Sequence  (Read 6814 times)

NitromanX

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Gamma Shift in Quicktime 7 Pro Image Sequence
« on: April 25, 2015, 11:16:18 AM »
I'm trying to create a fast and efficient workflow for my ML raw video.

Atm, I'm using the fabulous MLRawViewer 1.4.3 to convert the raw footage to .dng. I then export my dngs to 16 bit tiffs with VisionLog dcp profile added in Adobe Camera Raw. Finally, i create a ProRes HQ movie using Image Sequence via QTP7 - but it looks slightly lighter due to gamma shift.

Is there any way to stop this gamma shift ? I'm guessing the slight QTP 7 gamma shift is less of a problem since I'm using the VisionLog flat profile ?

I edit footage in FCP X as i don't have After Effects or Premiere and don't want to use Resolve as i'm a photographer and still getting my head around FCPX ! :)

Any advice appreciated.

NitromanX

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Re: Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #1 on: April 26, 2015, 01:37:56 PM »
Alternatively to using Quicktime Pro 7, is it possible to use Photoshop to Render Out video without the gamma shift ?

I know i can simply go File / Open - select the first tiff file and at the bottom of window click "Image Sequence" and hit Open. Set the required frame rate and then this imports all the tiffs into Photoshop's video timeline. You can also add Audio Track in the Timeline window by clicking "Add Audio" next to the music icon. Then just go File / Export / Render Video. This then gives us the options of DPX / H.264 or Quicktime then click Render and it's quickly rendered.

Is this video qulaity good enough to grade as it's not ProRes ?

It's a huge shame that Photoshop doesn't recognise the dng files for the image sequence as it would avoid the need to output all thise big tiffs.

Is there any way round this ?

I'm also guessing you could set up a Photoshop Action to Batch proces lots of files overnight which would be helpful too.

Does this method avoid the dreaded Quicktime Pro 7 gamma shift problems ?

sijak

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Re: Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #2 on: April 29, 2015, 01:01:03 AM »
Try to find out in finder trough inspecting qt to be sure that movie has rec709 gamma. Inspector shoud show hd 1-1-1 profile if so. Automator can be used to attach propper gamma if needed...
Cheers

DeafEyeJedi

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Re: Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #3 on: April 29, 2015, 01:50:03 AM »
@NitromanX:

Are you running PC or Mac?
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NitromanX

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Re: Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #4 on: April 30, 2015, 04:54:13 PM »
@ sijak - I can't see 1-1-1 in the profile file info. The .mov file was output from ACR 16 bit tiff files using QT7 Export to ProRes422HQ. I had applied VisionLog to the raw files in ACR to give a nice flat image.

Working this way, i guess any QT gamma shift is pretty irrelevant as the file will be graded anyway ?

@ DeafEyeJedi - I'm using a Mac and FCP X - so importing individual tiffs into FCPX is a slow process. 

Any better ways known by anyone ? :)

I've just discovered Pomfort Cliphouse but the debayering isn't as good as ACR and it causes my raw clips to show lots more moire / aliasing.

DeafEyeJedi

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Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #5 on: April 30, 2015, 05:59:20 PM »
Okay glad you are on the Mac boat with me otherwise...

Try a newer workflow that may be easier & quicker on your end:

MLVFS > AE (to apply Cinelog-C or VisionLOG) > FCPX

Back in the hey days I used to do the way you do with MLRV & Tiffs in QT7 but problem is if you use ProRes from MLRV ( you will lose the metadata that it needs for proper color grade - learned that the hard way from @Andy600 [emoji2] plus like you said it comes out a bit more contrasty than normal) as well as the strange gamma shift via QT7's tiffs AND plus the time consuming that comes along!
lol

anyway I suggest you to try this workflow if you really want to use FCPX to export final footage.
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

DeafEyeJedi

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Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #6 on: April 30, 2015, 10:51:54 PM »
Okay glad you are on the Mac boat with me otherwise...

Try a newer workflow that may be easier & quicker on your end:

MLVFS > AE (to apply Cinelog-C or VisionLOG) > FCPX (final grade & export)

Back in the hey days I used to do the way you do with MLRV & Tiffs in QT7 but problem is if you use ProRes directly from MLRV (you will lose the metadata that it needs for proper color grade - learned that the hard way from @Andy600 [emoji2] plus like you said it comes out a bit more contrasty than normal) as well as the strange gamma shift with QT7's tiffs AND plus the time consuming that comes along, eh!
lol

anyway I suggest you to try this workflow if you really need to use FCPX to export final grade.

*This is jm2c and it may be even more easier with DaVinci Resolve's workflow but my Mac's don't have the proper video graphic card to run MLV/RAW files on it.
5D3.113 | 5D3.123 | EOSM.203 | 7D.203 | 70D.112 | 100D.101 | EOSM2.* | 50D.109

NitromanX

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Re: Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #7 on: May 01, 2015, 09:35:57 AM »
Thanks again DeafEyeJedi ;) Will see how i get on with After Effects ! :)

sijak

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Re: Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #8 on: May 05, 2015, 12:37:56 AM »
@NitromanX Im on Mac too, so in Finder get Inspector for specific qt file by holding "alt" and pressing "cmd+I" at the same time. You will be able to see if it has or not rec709 by showing "HD (1-1-1)" or not showing one at all in case there is no metadata attached to the file. Remedy is to open Automator app and get in first column under Movies "add color profile", you will be able to assign one HD (Rec. 709) and to be sure that you have right gamma attached to a movie file.
Ivan

NitromanX

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Re: Gamma Shift in Quicktime 7 Pro Image Sequence
« Reply #9 on: May 06, 2015, 08:10:02 AM »
Thanks Ivan ... ;)

So my QT Movie file actually has a colour profile added if it shows "HD (1-1-1)" ? In which case i don't need to worry about any gamma shift ?

It's not too much of a problem atm but i do notice slight colour and gamma changes as I import and export from FCP X but that may just be normal.