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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Red Color Bars

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Michael Althaus

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Can somebody give me a tutorial on how to calibrate a monitor by using the red color bars? I can find tutorials on calibrating with color bars all over the internet, but they all use color bars different from the Red ones. Is there even a point in calibrating it with the color bars? Appreciate your help...
 
Nils Ruinet said:
Good question. Would it be possible to add SMPTE color bars to the Red One ?
Click to expand...

I believe you can already do this, and feed the HD-SDI signal to your monitor. The only caveat is that the signal coming from the Red is an internal debayered image and does not necessarily reflect the best you can get from the Raw.
 
If it is an HD video calibration reference on an external monitor you want, you should calibrate with an external SMPTE bar or test pattern generator. Forget the camera as a monitor calibration source. RAW doesn't provide a reference. Calibrate your camera LUT to the monitor, not the other way round.
 
David Rasberry said:
If it is an HD video calibration reference on an external monitor you want, you should calibrate with an external SMPTE bar or test pattern generator. Forget the camera as a monitor calibration source. RAW doesn't provide a reference. Calibrate your camera LUT to the monitor, not the other way round.
Click to expand...

See the IF at the beginning of the statement.

If what you want is just to see what the camera is doing, then you can calibrate the monitor to the camera.

If you are trying to deliver for broadcast then calibrating the camera to the monitor via LUT using external bars makes more sense.

If there is a post step in the middle (i.e. not live to air or somesuch) then calibrating the monitor to the camera is easier and makes more sense as a guide for what post will get to start working with.

RAW does provide a reference... but not to broadcast. Just to the RAW itself.

At least for me I am interested in what the camera is doing on set, not compliance with broadcast standards.
 
I just want to see what the camera is doing, so I would like to calibrate the monitor to the camera. Can somebody point me to a step by step explanation on how to calibrate the monitor using the type of color bars the Red One generates? The color bars the Red One generates are different from the "usual" bars, so I'm a little lost....
 
Alexander Ibrahim said:
If there is a post step in the middle (i.e. not live to air or somesuch) then calibrating the monitor to the camera is easier and makes more sense as a guide for what post will get to start working with.

At least for me I am interested in what the camera is doing on set, not compliance with broadcast standards.
Click to expand...

If you to want to see on set what the post guys will see when you hand the footage over either as proxies or with a LUT in the metadata, then you need to calibrate your external reference monitor using an external generator to the same standards the post facility uses. Otherwise you don't have a constant reference point between systems. Of course this doesn't apply to the Red EVF and LCD but I would try to match these with a properly calibrated external monitor for reference too using the internal camera bars as a guide.
 
Doesn't the camera send SMPTE bars when you put it in test signal mode_SMPTE? this is feeding to an external HD-SDI monitor... Or am I missing something about this - i.e. the red's smpte bars are inaccurate...or not the right bars... or what?
 
Red shoots raw, but that raw image data is always reinterpreted later into something else for viewing/distribution right?

A "calibrated" monitor should be something that can be used to "estimate" what an image will look like later.

We all know that the red "Tap" is only 720p, and you can view a downscaled, color-matrixed version of what the sensor sees - either with RedColor, Red Raw, or a user defined look. - Compared to what you see on the monitor you will end up with different (generally better) results later - however - to start with a calibrated monitor will let you get in the ballpark instead of the parking lot...more on this later.
 
Sorry - actually at work so I had to do something for a minute.

In any case - my theory is this:

You are on set with your Red MX.
You have a Panasonic BTLH-1760 "calibrated" to SMPTE bars
You are viewing in RedColor (default)
You shoot something.

You output it to (for the sake of argument here) 1280x720 Apple Prores 4444, no gamma correction, no curve adjustment, nothing.
It goes to the post house.
They open the ProRes file and view it on _their_ BTLH-1760 which is also calibrated to the same SMPTE bars.
They should be able to see (nearly) what you saw on your BTLH-1760 while present on set...

That would presume that having a SMPTE calibrated HD monitor as a baseline reference point between production and post-production could work - which is what I believe the original poster is hoping to achieve.

We all know that the power of a Raw Workflow allows us to treat the digital medium as a negative film stock instead of a reversal stock - and not just an HD video camera - and I am a firm believer in this imaging philosophy - however - people like to have a scientific reference point.

And - it is for this reason exactly that I personally believe the use of a chip chart/color chart or Red Cambook is an indispensable tool for imaging professionals working with Digital Cinematography systems. (more valuable than a calibrated monitor)
 
Dan Kanes is right on, this is exactly what I want. I just want to get a very rough estimate of what the picture can look like. So far, I just couldn't find any info on how to calibrate the monitor to the Red color bars. They are different from the ones I'm used to. Any help on this? I'm going to be working with Red again this weekend, and it would just be nice to have a monitor for the director that doesn't look washed out or has overly crushed black. I'm not using it to judge exposure or anything (that's what my light meter and the histogram is for).
 
Your best bet is to get a SMPTE test generator and calibrate the monitor based on that signal. At least then you would be Rec709 compliant. "What the picture can look like" can only be approximated.

As far as getting an idea of what the look can be like post-DI, that's what tests are for.
 
SMPTE Bars

SMPTE Bars

Yes, RED ONE has a SMPTE Color Bars test signal generator. The point is to make sure your monitor is calibrated to SMPTE / REC709, and then you can judge whatever you are outputting from the camera with the certainty the monitor is not mis-aligned and therefore creating a color cast.
 
Stuart English said:
Yes, RED ONE has a SMPTE Color Bars test signal generator. The point is to make sure your monitor is calibrated to SMPTE / REC709, and then you can judge whatever you are outputting from the camera with the certainty the monitor is not mis-aligned and therefore creating a color cast.
Click to expand...

How do I calibrate to the Red One SMPTE color bars? I just don't know the specific steps because the Red Color bars have a different layout from what I'm used to.
 
Bars

Bars

The RED test signal follows the SMPTE HD style rather than the standard "NTSC" bars... but the steps are the same as you would normally use. You can also use Luma Ramp to make sure the grey scale rendition is good.. i.e no crushing at low end or clipping at high end... and the Chip Chart to check skin tone patches are represented well on your monitor.
 
You go to blue only, and adjust your hue or phase adjustment so that all blue (or black and white) areas match in intensity. You adjust your chroma level, so that the thin stripe that seperates the top color bars from the YIQ stuff on the bottom - the colors in the stripe match in intensity - so they look the same.

Get out of blue only, and look at the bars in color. If you turn up the brightness, you will see in the blacks on the lower right, two different levels of black. This is called PLUGE. You adjust your brightness by eye, so you can just barely see the "brighter" black signal, but not enough so that is disappears. This is called "blacker than black" - which you don't want - you dont' want to crush your details in the black.

The Contrast adjustment (which are the white levels) are purely subjective - the old rule was to increase the contrast while looking at the 100% white bar, until the "old CRT" would "smear" - of course, modern CRT's, and of course LCD's don't smear, so you turn it to whatever looks correct to you - this will be the brightest your monitor will get (where you set the contrast).


check out this thread from a long long time ago.

Quoting Lyndel Crosley, SOC

http://reduser.net/forum/showthread.php?t=15007
 
being on reduser makes me realize how much I actaully don't know about cameras...
 
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