View Full Version : CF and Calabration


Bruce Gruber
October 2nd, 2010, 04:36 AM
question..

What is the best way to calabrate, the monitor to FL and Adobe PP? Does anyone have a process they use and or tools?

When I tweek color,exposure in FL it does not look the same in PP and then when I burn it looks different on the tv. Now I realize the TV settings effect the color ect. But I need FL and PP to look the same?

David Newman
October 2nd, 2010, 09:39 AM
If you use the OpenGL option in both FirstLight and PPro, the outputs will much. The problem occurs with the default YUV surface which some graphics card get wrong, the OpenGL surface is RGB.

Ben Hickson
October 3rd, 2010, 12:02 PM
How do I select the open GL surface? Can I select it in Vegas? What is my best option for accurate color in Vegas? I find the videos look much different on my roommate's macbook pro.

David Newman
October 3rd, 2010, 03:18 PM
Vegas has it own unique set up problem for color correction (nothing to do with CineForm). It uses a non-standard display black level of 16. Research studioRGB and Vegas.

Bruce Gruber
October 6th, 2010, 02:57 AM
Hi Dave not to sound stupid.. But where do you set openGL? I am using PP? Also is there a setting for the video card?

David Newman
October 6th, 2010, 08:24 AM
In the playback settings for the CineForm editing mode.

Alex Raskin
October 8th, 2010, 09:46 PM
Speaking of calibration.

FL needs to have a setting for Color Space.

For instance, I use a full gamut display. It is calibrated. However if the *application* does not enforce color space that matches the source being displayed (video, images' color space..) then the colors on the monitor will be off.

For instance, when I use Photoshop, I set it to sRGB color space, and all is good. If I don't, default colors are way off. This is a standard issue with full gamut displays.

Just like image editing applications (Photoshop), NLEs also have color space settings.

Whatever the application used on full gamut display, the application needs to tell the system how to interpret its display.

FirstLight should too.

Currently I am forced to only use it on my 2nd monitor (which is NOT full gamut.)

If a choice of color spaces is not possible, then FL should at least default to Rec 709 or sRGB. This way both regular and full gamut displays will show the video colors correctly.

Any chance to have that done in the upcoming releases?..

David Newman
October 9th, 2010, 10:54 AM
Alex, that doesn't make sense to me. Your monitor should have a control to match it input, not the other way around. Can't you set sRGB/Rec.709 etc. in the monitor? I'm not should that there is anything we can change on our end.

Alex Raskin
October 9th, 2010, 11:19 AM
Setting sRGB in display will negate the advantage of wide gamut to begin with.

This is a known intricacy with wide gamut displays, they need color managed applications to correctly tell them what color space is used.

For example:

WIDE GAMUT ADOBE RGB LCD Monitors Screens Troubleshooting Over Saturated sRGB Color Reviews on the Web Tutorial (http://www.gballard.net/photoshop/srgb_wide_gamut.html)

Adobe image processing software supports color management just fine (in CS5 anyway.)

We need same in FL please.

David Newman
October 9th, 2010, 11:55 AM
FirstLight decodes the image without any color space assumptions, it is up to you how to choose to interpret it. Running through a colorspace transforming LUT, would like break the workflow for other tools. I could see adding a switch to studio RGB for the output OpenGL and dual link HDSDI displays, this is a wider gamut, but everything else would break the WYSIWYG that FirstLight does so well.

Alex Raskin
October 9th, 2010, 12:58 PM
>> I could see adding a switch to studio RGB for the output OpenGL

I think that'd take care of things. Both standard and wide gamut displays will then show the same picture of FL monitor window.

Right now wide gamut display shows oversaturated reds in FL, of course, as it is always the case with WG displays when the application does not tell tell system explicitly what is the source's color space. (And WG display then assumes the source is also wide gamut, which leads to incorrect picture shown. The same occurs, for example, with other image display applications - such as web browsers - that do not support color profiles. The ones that do support color profiles - Safari - show images correctly on the wide gamut displays.)

Steve Kalle
October 11th, 2010, 09:10 PM
Alex,

I think you have a misconception of how displays work. A LCD with 110% of NTSC (aka 'Wide Gamut') does not automatically reproduce 'accurate' colors nor does it automatically produce 'better' colors than a LCD with 100% NTSC (or lower).

For proper and accurate color correction & color grading, the MONITOR must be hardware calibrated to the specific color space, ie 601, 709, DCI, of the destination.

"Both standard and wide gamut displays will then show the same picture of FL monitor window"
The only possible way for 2 different monitors to produce similar images is by using very expensive profiling & calibration software.

Alex Raskin
October 12th, 2010, 06:23 AM
Steve, I own both standard and wide gamut monitors, and they are calibrated, so my remarks come from real life experience, not theory. However I did provide a link to the theoretical coverage of the issue, as well - did you read it?

This is how wide gamut displays work, whether you like it or not, so the software needs to indicate what color space to use or the colors will be off (way too saturated, mainly with Red.) End of story.

Steve Kalle
October 12th, 2010, 12:05 PM
Basically, what you are saying is that NO ONE needs a professional broadcast monitor hardware calibrated for PROPER color correction & grading - all one needs is to apply a color profile.

Believe what you want but you can't dispute what I stated, which is also from experience. I have an Eizo CG243W ($2300) that is HARDWARE calibrated to Rec 709 for HD, Rec 601 for SD and DCI for Film. I also have several Dell Ultrasharp LCDs calibrated to D65 that are 'Wide Gamut' and NONE look anywhere close to the Eizo with color space profiles applied.

The ONLY time I need to apply any color profiles is when I use my Panasonic BT-LH1710W ($2900) for grading which is connected via HD-SDI to a BlackMagic Decklink Extreme 3D.

Go here and tell me if your monitors get a perfect score LCD monitor test images (http://www.lagom.nl/lcd-test/) (My Eizo does)

David: for FL, wouldn't applying a Rec 709 LUT work just fine because that is the 'native' color space of HD video, which would work fine in an HD workflow?

Alex Raskin
October 12th, 2010, 12:28 PM
Steve Kalle: Basically, what you are saying is that NO ONE needs a professional broadcast monitor hardware calibrated for PROPER color correction & grading - all one needs is to apply a color profile.

Nonsense - don't know where did you read me saying that.

Calibration provides accurate color representation, and my monitors are calibrated.

Wide gamut monitors (yes, after calibration...) do require color-managed applications to display images/video correctly. This includes anything from web browsers to NLEs, FirstLight included.

Without color management, colors will always appear oversaturated, especially red.

Thus a need for FL to provide color management - like a sRGB or Rec 709 option David Newman proposed.

Since there appears to be quite a confusion, here's the quote from the best practical article I have found, to date, on wide gamut displays calibration and profiling. Author, Johan Steen, says it better than I ever could, here:

"# Wide Gamut
Starting with the oversaturated colors on wide gamut displays. In the past displays were showing colors that were pretty close and limited to what we know as the sRGB color space, with newer displays we have a much larger color range to work with – closer to the Adobe RGB color space. When an application wants to display a pure red pixel (RGB 255,0,0) it sends a signal to the screen that the brightest red should be displayed.
A non color aware application (we’ll go deeper into this further in the article) just dumbly assumes that the display is within the sRGB range and blindly sends the raw pixel data where in the case of a wide gamut screen, which can display much brighter colors, receives the signal of displaying the brightest red, do just that, displays the brightest red that it’s capable of, which then leads to the extremely oversaturated image.
# Calibration
When calibrating a LCD display with a hardware device like the Spyder 3 from Datacolor, most people understandably assumes that the display will be calibrated to correctly display colors in the sRGB space.
That is an incorrect assumption.
A more correct label is that the display device get profiled, that means that the display’s color performance and characteristics get measured and saved in an ICC profile that color aware applications will use to display colors correctly within selected color spaces. Some calibration do also occur but non in the same sense as in the CRT era where displays where within the sRGB range. LCD displays doesn’t get truly calibrated at all towards a specific color space, they get their Gamma and White Point values calibrated. This is an important concept to understand and as soon as I got it, it all started to make sense to me.
Profiling is the keyword here.
# Non Color Managed Applications
Even though the display now has been calibrated and profiled, non color managed applications will still display colors incorrectly, this is especially true on wide gamut displays. And there is simply nothing that can be done about that except using color managed applications. Wide gamut displays are great and the future, but software developers need to catch up with the new hardware and stop assuming all displays are within the sRGB range."

Source and full article here. (http://www.artstorm.net/journal/2009/07/color-management-wide-gamut-dell-2408/#concepts)

David - you see why FL should manage colors?

I think the number of people using wide gamut displays will only increase over time, so it makes sense to accommodate us ;)

Steve Kalle
October 12th, 2010, 12:53 PM
"Calibration provides accurate color representation, and my monitors are calibrated."

This is not correct. You are using SOFTWARE calibration which only gets the monitor set on the correct gamma and white point by adjusting the video card's output.

Hardware calibration, on the other hand, is setting everything from gamma and white point to color primaries for each color space WITHIN the monitor itself.