adjust gamma for windows pc

Posted by Jamie Kelley 
adjust gamma for windows pc
September 27, 2006 11:42PM
A couple of years ago, some one wrote a short white paper on adjusting gamma settings in FCP to compensate for darker PC monitors. I can't find any reference to that article either in the LAFCPUG or Ken Stone archives.

Does anyone remember this, moreover, any advice on gamma compensations?

Thanks,

Jamie
Re: adjust gamma for windows pc
September 28, 2006 04:13AM
mac gamma is 1.8
pc gamma is 2.2 I think.

You could set your own monitor to 2.2.
Re: adjust gamma for windows pc
September 28, 2006 01:24PM
Not so simple. In addition to the difference between PC and Mac monitors, there is the gamma distortion that Final Cut insists on adding. It's 1.2 one direction and 0.8 the other.

There is a much more complicated series of numbers if you're particular about your video levels, but that will get you in the ballpark quickly.

Koz
Re: adjust gamma for windows pc
September 28, 2006 02:14PM
Thanks guys.

My clients are particular about the video levels so I'd appreciate the complicated series of numbers if I can apply them.

I threw in a gamma filter at 0.86 and changed my monitor to a PC calibration. Worked for me however the client still sees it as too dark.

Should I crank down the gamma filter even more? Or I am better adjusting in a color correction filter?

[www.webfilms.ca]

Jamie
Re: adjust gamma for windows pc
September 28, 2006 03:42PM
Jamie, are you trying to judge timeline color, brightness etc. on your computer monitor? You should be using an external video monitor for that. Or are you meaning that your exported quicktime, window's media (whatever format) is playing back darker?

Steve
Re: adjust gamma for windows pc
September 28, 2006 03:47PM
What is he actually complaining about? The graphics look fine on a PC to me. Maybe he needs to turn the brightness on his monitor up.

On the other hand the conference room scenes are shot too dark in my view, too much contrast for this type of delivery. Might look great on film, but on the web it's not going to work. You might be able to improve it some in CC but it's going to get noisy.

All the best,

Tom
Re: adjust gamma for windows pc
September 28, 2006 04:22PM
Thanks Tom. That was my conclusion too. I started color correcting and it got funky fast especially when eyedropping the blacks and mids. Anymore gamma filter correction makes it too noisy as well.

I used stock for the conference room. The client previewed the clips and gave his approval. I may try a slight cc to lesson the contrast.

Normally I do use my external video monitor, however this piece is strictly for the web so I thought it unnecessary.

Thanks to all for the feedback.

Jamie
Re: adjust gamma for windows pc
September 29, 2006 05:04AM
Just as a swerve ball has your client had his monitor calibrated?

Derek

If your using Shake come and post some questions on the LAFCPUG Shake forum cheers Derek
Re: adjust gamma for windows pc
September 29, 2006 05:17AM
I think this is the paper you were thinking of. It's a bit old now..

[www.kenstone.net]

Re: adjust gamma for windows pc
September 29, 2006 09:50AM
Bingo. That's the one Jude, thanks.

And Derek, I did mention to the client that his monitor might need recalibration, but it's difficult to drive home the point when he has no idea of what that means.

I performed one last tweak of the highlights slider and came up with something that satisified him.

[www.webfilms.ca]

Thanks again to everyone.
Re: adjust gamma for windows pc
September 29, 2006 03:12PM
On PCs at least, you can go here:

[www.kozco.com]

...and see if you can see all the steps of the gray pattern including the zebra stripes in the middle. Display it in your browser; Netscape, Internet Explorer, FireFox, etc. There are instructions underneath that I probabley need to rewrite.

That will get you in the ball park in a big hurry. This also works with Macs set to a monitor value of 2.2 for video, not 1.8 for print.

There is another item Stone wrote about gamma problems. Scroll way down toward the end:

[www.kenstone.net]

We are currently stuggling with this problem because one of our productions is all FCP all the time. The problem is we are *not* all FCP all the time. We have hundreds of Other Machines and we can't transfer graphics between the groups without damage.

Further, nobody wants to hear that we need to go through Extra Steps to make them match. Extra Steps translates to Extra Money. You want to get a producer's attention in a big hurry, use any of those Magic Words.

Even further yet, we not only have the "straight" monitor gamma of 2.2 and the oddball Mac 1.8 plus the 1.2 distortion, we also have our Film Lookup Tables which distort the picture to make the monitors look just like film.

Yes, it is too late to call in sick. I thought of that.

Koz
DM
Re: adjust gamma for windows pc
September 29, 2006 09:17PM
Interesting observation. I've been doing video's at work that make there way to a web download. They look good on a monitor or projected but are very dark when viewing on the computer monitor after download.
Is there anything to this? Something I don't realize to be sure.

regards
dm
Re: adjust gamma for windows pc
September 30, 2006 12:42PM
<<<Something I don't realize to be sure.>>>

Most, is not all, PC monitors are misadjusted. In the very early versons of this:

[www.kozco.com]

I went around the company, some 350 monitors at the time, and I didn't find any of them even remotely close--except the brand new ones. Most users were only watching the top 80% of the brightness levels. Everything else was buried in blackness.

LCD monitors help because they don't have that age-drift thing, but they have the problem of not being able to get to black at all without crushing and distorting the picture at dark gray.

PC monitors, uncompensated Mac (2.2) monitors and television systems should be able to match. They all have about 2.2 Gamma from the characteristics of the tube.

We know this from actually doing it with our G5s, a moderately large television system, and a Minolta Color analyzer.

Koz
DM
Re: adjust gamma for windows pc
September 30, 2006 06:41PM
Well, I guess I better check my own again. Viewsonic Pro 21" LCD series. I still suspect the encoder however. It's a Pro unit made by some company that I can't recall at the moment. I think it's Digital Rapids. As usual, there's an IT geek behind it stroking his Blackberry.
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