Field Of View Dreams … Why it does not matter or we are hosed.

Now if we move the meter even further back, it will start to look like this.  It is overshooting the edge of the test pattern that we want to take readings of.  This is bad since any readings would be comprised of the white part as well as the black parts.  The readings are polluted so we cannot do something like this.  Have to move the meter closer again.

FOV_too_large
FOV of meter too large now

Now back to the ideal about how the meters should perform.  As long as we don’t go too far back and pollute the FOV with different elements, our meter readings should be effectively the same. They won’t ever be exactly the same given the nature of our instruments and of course the room reflections might add a bit of variation here as well.

FOV Comparison
FOV Comparison

So this is our expectation on how things should work out in real life on a meter.  Let’s see how this plays out on my Jeti 1211 spectro (My previous CS 200 behaved the same way).  This portion is from the original article about my experiment on a formerly new Samsung E8000 series LED/LCD set.

I had a chance to play with one of the new Samsung E8000 series LED sets.  I first placed the C6 up to the set and calibrated the display with that device and the calibration tables.  The C6 is in contact with the face of the screen.  Next up I took some readings from the Jeti spectro to see how well the C6 did.  The Jeti was tripod mounted and about 22 inches back from the screen.  The laser pointer on the jeti showed it was looking at a similar surface area of the screen.  The following then is a series of images starting with the C6 tables version and then eight readings of the same tv, but spaced about 9 inches further away each time.  (The FOV increases every time the meter is moved back from the TV)  So with the first reading being 22 inches, the second is 31 inches … then 40, 49, 58, 67, 76, 85.

C6 Original Run … TV calibrated based on Tables
Jeti at 22″ … Same FOV as C6
Jeti at 31″
Jeti at 40″
Jeti at 49″
Jeti at 58″
Jeti at 67″
Jeti at 76″
Jeti at 85″

 

Alright, so the behavior here actually matches the expectations from the theory.  Changing the FOV does not matter as long as the device continues to look at the same test pattern.

Michael Chen

Michael Chen is the only THX Video Systems Instructor in Canada, and beyond these borders, is one of just two THX Video Instructors in the entire world.  He has actively consulted with Spectracal and ChromaPure and has created numerous education videos on the calibration process with still more to come.  His Video Calibration Training Series has quickly become the most comprehensive and simple to understand learning tool on the market today.  He has also taught classes for both the ISF and Spectracal as well and is now spearheading his all new TLVEXP calibration training program. Let Michael teach you Video Calibration and add that additional income stream to your installation and integration business

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