View Full Version : Differences in color from XDCAM Transfer to FCP to QT


Simon Frances
February 14th, 2008, 07:47 PM
Hi,

Can someone tell me why I’m getting two different images from the same clip?

Screen grab of clip in XDCAM Transfer Here (http://www.inspiredsolution.co.uk/differences_in_color_from_xdcam_to_fcp_qt/xdcam_transfer.jpg)

Screen grab of same clip exported from XDCAM Transfer, imported into FCP and displayed on the canvas. (The viewer shows the same as the canvas) Here (http://www.inspiredsolution.co.uk/differences_in_color_from_xdcam_to_fcp_qt/fcp_canvas.jpg)

Screen grab of same clip in QuickTime exported from FCP Here (http://www.inspiredsolution.co.uk/differences_in_color_from_xdcam_to_fcp_qt/qt_from_fcp.jpg)

I’ve not made any adjustments to the clip at all, hence the screen grab of the QuickTime window is the same as the XDCAM Transfer screen grab.

Any help would be most appreciated.

Regards,
Simon

Alexander Ibrahim
February 15th, 2008, 04:07 AM
Hi,

Can someone tell me why I’m getting two different images from the same clip?

...

I’ve not made any adjustments to the clip at all, hence the screen grab of the QuickTime window is the same as the XDCAM Transfer screen grab.


You should really read those nice manuals Apple included with your software.

The thing is that you are mistaken- you are adjusting the image which is the cause of your problem.

Here are the relevant sections:

Volume 1, Part 3, Page 219

Volume 3, Part 4, page 668

You are having a gamma matching issue. I don't know which application is causing the snafu (probably Final Cut), but you can correct it in Final Cut.

Here are the instructions from Volume 3, Part 4, page 671- but I SERIOUSLY advise you to read the sections above before fooling with the settings.

1 Choose Final Cut Pro > User Preferences, then click the Editing tab.
2 Choose one of the following options from the Gamma Level pop-up menu:

* Source: If you have already adjusted the gamma of your media to work with previous
versions of Final Cut Pro, choose this option to ensure that clips appear the same as in
previous versions. This option uses QuickTime to interpret the gamma of imported
media files.

* 1.8: Choose this option when importing media files created with the Mac OS or
created by an application in which you specified a gamma value of 1.8.

* 2.2: Choose this option when importing media files created with non–Mac OS
systems or created by an application in which you specified a gamma value of 2.2.

* Custom: Choose this option to enter any gamma value you wish in the Custom
number field.

I guess that you should be using the "Source" option... but you may have to experiment.

I should also note that you really ought to be using external monitoring.

Simon Frances
February 15th, 2008, 02:31 PM
Tried various gamma setting as suggested but made no difference :( I'm stumped as to what it could be.

Any other suggestion anyone?

Thanks,
Simon

Alexander Ibrahim
February 15th, 2008, 05:26 PM
Tried various gamma setting as suggested but made no difference :( I'm stumped as to what it could be.

Any other suggestion anyone?

Thanks,
Simon

And you read the relevant manual sections? Cause that's important too... and the manual mentions other potential solutions.

Simon Frances
February 15th, 2008, 08:47 PM
Hi Alexander,

Although after changing the Gamma Correction to "Approximate", there is still no real difference. But as you mentioned, I really need to get an external monitor. However I would still like to get this to work.

Thanks
Simon

Mark OConnell
February 15th, 2008, 10:33 PM
Did you try going into your QT Player preferences and checking the "Enable Final Cut Studio color compatibility" check box?

George Kroonder
February 16th, 2008, 12:06 PM
You may be experiencing luminance translation 'issues' with regard to ITU-R 601 specification vs. 'computer' RGB. A good start may be this atricle on PVC (http://provideocoalition.com/index.php/cmg_keyframes/story/luminance_ranges/).

George/

Alexander Ibrahim
February 16th, 2008, 11:13 PM
You may be experiencing luminance translation 'issues' with regard to ITU-R 601 specification vs. 'computer' RGB. A good start may be this atricle on PVC (http://provideocoalition.com/index.php/cmg_keyframes/story/luminance_ranges/).

George/

On this note it may be worth checking your sequence settings and making sure you are rendering in YUV, or even YUV high precision.

(i.e. you may be rendering in RGB)