View Full Version : calibration question


James Klatt
July 10th, 2005, 04:36 PM
I use a Panasonic DVX100a, G5, Viewsonic A75f CRT, and Final Cut for shooting and editing wedding videos. I know it's ghetto, but I have been using a 14-inch consumer Panansonic television(through a Sony Digital/Audio converter)for a second monitor to see what the image might look like on a TV(I know this is probably a TERRIBLY unstable process to gauge what my product will look like when my customers pop in their finished DVDs and watch it on their TV's or computers).
I know it might now seem like it, but my image ouput is really dear to me and would love to find an economical way to help myself(and customers) out in getting the best product I can deliver. This has become more crucial since my photography skills are moving to more nuanced levels!
Is my ghetto monitor hurting me more than helping me? Am I ridiculous in that I calibrate with the color bar technique? Are there solutions/tips that would be in the ballpark of a "few' hundred dollars or LESS that would translate to any image stabilization?
It just breaks my heart to know that I spend so much time properly exposing clips and sometimes color-grading to see it get some nasty orange tint or super contrast on some TV set. Thanks!

Glenn Chan
July 10th, 2005, 10:19 PM
James, here's a few things you can do.
#1- Match color temperature of all light sources in your room- that would be windows, lights, monitors, etc.
Killing light sources can help (i.e. get curtains).
On your monitors, hopefully they have color temperature controls. Your Viewsonic may have RGB controls, which are a better way of setting color temperature.

Display white on your monitors and put something white on the table. If you like to work in light, get light fixtures that match your TV. Not sure if this is possible. Ideally, your TV will have a color temp setting for 6500k. If so, get 6500k fixtures.
Or... just work in darkness.
Match everything else to your TV. Whites won't look exactly the same on all monitors because the phosphors for R, G, and B have components in the other colors.

This is probably the #1 thing you can do, and it's possible to do.

Your eye kind of has an automatic white balance control. Look at something long enough and it'll appear white. If there's multiple light sources in a scene, you can see that they aren't all white at the same time.

#2- Try the calibration instructions at www.videouniversity.com/tvbars2.htm

You kind of really need the right blue gel (wratten something something) or blue gun. If you don't have the gel, just put the controls in their middle position- it'll actually be pretty close. That calibration only calibrates the analog components in the monitor... the phosphors may still be messed.

However, do calibrate to the PLUGE bars. Your TV image may be too dark if you're using a consumer camcorder as a bridge (because of the 7.5IRE setup issue).

*You do need to let the monitor warm up. Colors will change as the monitor warms up.

#3- Run test patterns through your monitor to check for accuracy.
Throw up a properly exposed image and desaturate it to black and white. Note any color casts- I suppose you'll have to mentally compensate for this.
Pay attention to the dark colors- these are typically the colors with color casts.

Also put up a black to white gradient on your monitor. Check that the transitions are smooth. Note that illegal colors won't display right on your TV monitor. Throw the broadcast safe filter on, or do a gradient from 16 16 16 to 235 235 235 (RGB values). In FCP, "256" sometimes gives 235 235 235 (RGB).

#4- Turn off cheats on your monitor. The one I know of is flesh tone correction, called "auto color" on the TV I own.

#5- $600+shipping will buy you a CRT-based broadcast monitor that would work for field use too. Buying demo and b stock units can be ok, but be very wary about used monitors (monitors are prone to problems as they age).

Broadcast monitors are easier to calibrate. The more expensive ones will autocalibrate themselves to color bars.


At the end of the day though:
A- Your setup probably won't be too color accurate to what things are supposed to be.
B- Your setup probably doesn't need to be super accurate. Aim for good enough. Your time to better spent making your footage look better, and consistent in color/exposure.
C- Even broadcast monitors may not give you a good idea of what the average viewer sees. The average TV set is overly bright, saturated, contrasty, and the color temperature is way too high (everything looks a little blue) to make things look brighter. You may wish to tone things down in anticipation of this.