Gamma shift. That old chestnut at DVinfo.net

Simon Wyndham · November 23rd, 2009, 11:07 AM

Like many I am sick of the gamma shift problem with FCP and Compressor. Snow Leopard doesn't appear to have cured the problem. Can any FCP7 users comment on their experiences? Is there any workable work around for FCP6 other than rendering out huge Animation codec based files first before going into Compressor. Does FCP7 solve the gamma shift issue?

Perrone Ford · November 23rd, 2009, 11:15 AM

I used to have this issue when I would get files from FCP users. I am on a PC. Having them use Avid's DNxHD codec solved the problem cross-platform. Maybe it will solve this issue for you as well. It's free, so couldn't hurt to try it. Download it from Avid's webpage.

Robert Lane · November 23rd, 2009, 11:42 AM

Great idea but unfortunately that won't work. This problem is at the core of how FCP deals with displaying color.

Here's everything you need to know - the short version: There's no fix and it's a long-time bug that Apple hasn't yet addressed.

http://www.dvinfo.net/forum/non-line...n-exports.html

Barry Goyette · November 23rd, 2009, 08:35 PM

A music video I shot recently has just been picked up for broadcast. In the past I've worked through all the gamma shift issues between FCP and QT player, so I get that...but now that I need to submit for broadcast, I'm not sure what I should do. Adjust the gamma so it looks good on my monitor.....or leave it alone cuz FCP really does know what it's doing relative to broadcast (which makes sense to me). In the past it's always seemed like things I've burned to DVD look fine on my TV set.

Anybody?

Simon Wyndham · November 24th, 2009, 03:42 AM

The Avid DNxHD codec is no good for FCP. What happens is that FCP applies an additional gamma shift to it as it does for the Canvas window. So if I view an Avid DNxHD timeline through the MXO, the view on the MXO ends up with two 2.2 gamma applications, so it looks just as dark as the canvas window!

Robert Lane · November 24th, 2009, 08:11 AM

Quote:

Originally Posted by Barry Goyette

A music video I shot recently has just been picked up for broadcast. In the past I've worked through all the gamma shift issues between FCP and QT player, so I get that...but now that I need to submit for broadcast, I'm not sure what I should do. Adjust the gamma so it looks good on my monitor.....or leave it alone cuz FCP really does know what it's doing relative to broadcast (which makes sense to me). In the past it's always seemed like things I've burned to DVD look fine on my TV set.

Anybody?

If indeed you're going out to broadcast then you need a "broadcast monitor" or another balanced NTSC 601/701 monitor. There's a wealth of data here on the forum about choosing and setting up external monitors for broadcast color balancing.

You also have a very good reference and walk-through about these setups right in your built-in users manual in FCP.

Barry Goyette · November 24th, 2009, 12:21 PM

Thanks robert...I've been stuck on the web for far too long. As a mostly still photographer, It's been a long time since I had a broadcast monitor hooked up to my system...I just figured we'd moved past that by now....guess not. thanks for reminding me how it's done. I'll go dust off the old Sony.

Barry

Ryan McBride · November 24th, 2009, 04:35 PM

I read a while back that QT files encoded as H264 automatically adjusted for the computer gamma (mac or PC). I think it was an article on Ken Stone's site. Does this sound familiar to anyone? I will see if I can dig it up? I guess this still doesn't address the different look between the quick time player and the Final Cut viewer.

Robert Lane · November 25th, 2009, 02:11 PM

Quote:

Originally Posted by Barry Goyette

Thanks robert...I've been stuck on the web for far too long. As a mostly still photographer, It's been a long time since I had a broadcast monitor hooked up to my system...I just figured we'd moved past that by now....guess not. thanks for reminding me how it's done. I'll go dust off the old Sony.

Barry

If you're final output was to web only then viewing it on your computer LCD would be perfect. But in fact any TV set whether it's SD or HD has a completely different gamma space and much more limited dynamic range than a computer screen, so for broadcast you really have to see things on a broadcast monitor to know exactly what you're getting.

That's also why all pro NLE's have a built-in "broadcast safe" color filter to help you compress color/gamma and keep things closer to a proper IRE value.

Maybe at some point the NTSC and PAL signals will support a broader color spectrum but that's probably another 15-20 years out when fiber and satellite has less compression in the signals for network push.

Barry Goyette · November 25th, 2009, 05:58 PM

Hey Robert,

So I got thinking about this, and I have follow-up question. So, say I get my broadcast monitor up and running this weekend, and I adjust my final cut pro project just so...and then I go to export the video thru compressor...aren't I really still in the same boat...won't the exported clip have a different gamma than what I'm viewing in FCP (or is it the other way around...the clip is the same gamma, but FCP views it differently than QT...PC's whatever...in which case I just trust what I see on the sony monitor, export away...and it will look fine on some cable channel in Buffalo that I'll never see here in californiyay?)

Barry

Robert Lane · November 25th, 2009, 06:27 PM

Assuming your monitor is properly setup and you make your adjustments based on that montior then that's what the final product will look like when broadcast.

The color disparity issue is specific to viewing on your Mac monitor, not the final broadcast result.

November 23rd, 2009, 11:07 AM	#1
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	Gamma shift. That old chestnut Like many I am sick of the gamma shift problem with FCP and Compressor. Snow Leopard doesn't appear to have cured the problem. Can any FCP7 users comment on their experiences? Is there any workable work around for FCP6 other than rendering out huge Animation codec based files first before going into Compressor. Does FCP7 solve the gamma shift issue?

November 23rd, 2009, 11:15 AM	#2
Perrone Ford Inner Circle Join Date: Nov 2006 Location: Tallahassee, FL Posts: 4,100	I used to have this issue when I would get files from FCP users. I am on a PC. Having them use Avid's DNxHD codec solved the problem cross-platform. Maybe it will solve this issue for you as well. It's free, so couldn't hurt to try it. Download it from Avid's webpage. __________________ DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.

November 23rd, 2009, 08:35 PM	#4
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	but how about for broadcast? A music video I shot recently has just been picked up for broadcast. In the past I've worked through all the gamma shift issues between FCP and QT player, so I get that...but now that I need to submit for broadcast, I'm not sure what I should do. Adjust the gamma so it looks good on my monitor.....or leave it alone cuz FCP really does know what it's doing relative to broadcast (which makes sense to me). In the past it's always seemed like things I've burned to DVD look fine on my TV set. Anybody?

November 23rd, 2009, 11:42 AM	#3
Robert Lane Go Go Godzilla Join Date: Nov 2004 Location: Scottsdale, AZ USA Posts: 2,825 Images: 15	Great idea but unfortunately that won't work. This problem is at the core of how FCP deals with displaying color. Here's everything you need to know - the short version: There's no fix and it's a long-time bug that Apple hasn't yet addressed. http://www.dvinfo.net/forum/non-line...n-exports.html

November 24th, 2009, 03:42 AM	#5
Simon Wyndham Trustee Join Date: Dec 2003 Location: Malvern UK Posts: 1,931	The Avid DNxHD codec is no good for FCP. What happens is that FCP applies an additional gamma shift to it as it does for the Canvas window. So if I view an Avid DNxHD timeline through the MXO, the view on the MXO ends up with two 2.2 gamma applications, so it looks just as dark as the canvas window!

November 24th, 2009, 12:21 PM	#7
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	Thanks robert...I've been stuck on the web for far too long. As a mostly still photographer, It's been a long time since I had a broadcast monitor hooked up to my system...I just figured we'd moved past that by now....guess not. thanks for reminding me how it's done. I'll go dust off the old Sony. Barry

November 24th, 2009, 04:35 PM	#8
Ryan McBride Regular Crew Join Date: Feb 2004 Location: Seattle WA Posts: 28	I read a while back that QT files encoded as H264 automatically adjusted for the computer gamma (mac or PC). I think it was an article on Ken Stone's site. Does this sound familiar to anyone? I will see if I can dig it up? I guess this still doesn't address the different look between the quick time player and the Final Cut viewer.

November 25th, 2009, 05:58 PM	#10
Barry Goyette Trustee Join Date: Oct 2001 Location: San Luis Obispo CA Posts: 1,195	Hey Robert, So I got thinking about this, and I have follow-up question. So, say I get my broadcast monitor up and running this weekend, and I adjust my final cut pro project just so...and then I go to export the video thru compressor...aren't I really still in the same boat...won't the exported clip have a different gamma than what I'm viewing in FCP (or is it the other way around...the clip is the same gamma, but FCP views it differently than QT...PC's whatever...in which case I just trust what I see on the sony monitor, export away...and it will look fine on some cable channel in Buffalo that I'll never see here in californiyay?) Barry

November 25th, 2009, 06:27 PM	#11
Robert Lane Go Go Godzilla Join Date: Nov 2004 Location: Scottsdale, AZ USA Posts: 2,825 Images: 15	Assuming your monitor is properly setup and you make your adjustments based on that montior then that's what the final product will look like when broadcast. The color disparity issue is specific to viewing on your Mac monitor, not the final broadcast result.