Dept of Color Color Correction Suite Bias Light

How Viewing Environment Conditions Can Corrupt Or Enhance Your Monitor Calibration- Updated​

Fundamentally, all of motion imaging technology is based upon human visual perception. The world’s most perfect calibration instrument cannot fully duplicate or measure how our brain interprets what our eyes see. Certain attempts have been made to emulate how humans perceive light but science has yet to produce an instrument which tells the whole story.

The Society of Motion Picture and Television Engineers (SMPTE) human factors work resulted in their recommended practices document RP166-1995: “Critical Viewing Conditions For Evaluation Of Color Television Pictures.” This is the report from which D65 bias lighting has been derived. The document actually devotes much more attention to color perception than eyestrain.

SMPTE updated this research after 22 years and published a revised standards and recommended practices document, SMPTE ST2080-3:2017, titled: “Reference Viewing Environment for Evaluation of HDTV Images.” Its introduction reads:

“The creation of television images that are intended to follow a standard of consistency in reproduction requires definition of a reference display, of a controlled viewing environment, and of a set of measurement procedures to enable consistent calibration of both display and environment. This document specifies a controlled viewing environment referred to as the Reference Viewing Environment.”

In other words, video program producers value image fidelity in order for their intended audience to enjoy a faithful reproduction of their workmanship. They adhere to industry standards and best practices to preserve the motion images they produce for display. It is acknowledged that both video monitors and viewing room conditions must be calibrated in order to provide an authentic viewing experience. SMPTE’s research validated that room surface colors and ambient lighting characteristics affect the viewer’s perception of the video display’s image.

Here are some links that dramatically demonstrate how ambient lighting and surrounding surface colors in the room can cause us to think we see black levels, contrast, and/or colors a certain way.

https://www.echalk.co.uk/amusements/OpticalIllusions/colourPerception/colourPerception.html

https://www.echalk.co.uk/amusements/OpticalIllusions/colourPerception2/colourPerception2.html

Professional monitor environments (where critical image analysis is conducted for mastering video programs) use tightly controlled lighting and neutral colored surfaces surrounding the display. The demonstrations above make very clear the importance of incorporating similar room conditions, if image fidelity is desired. This material also makes abundantly clear how destructive to image fidelity the Philips ‘Ambilight’ colored light features and interior decorating choices can be.

The Ideal-Lume Pro Desk Lamp is the most recent product that CinemaQuest has developed for professionals to use on their control console area to preserve a CIE D65 ambient environment in compliance with the new SMPTE standard.  It is a collaboration between Cinemaquest and the folks at MediaLight.

Human visual perception is seldom sufficiently understood when consumer display systems (and even many professional ones) are designed and implemented. Since our human vision is so adaptive, we can think we perceive a “natural looking” image but actually don’t, if viewing environment conditions are incorrect. The demonstration material at the links above should provide considerable practical reinforcement for folks who have a hard time being persuaded by imaging science theory alone, or even the decades of proven imaging industry professional practice.

If you think there is some electronic trick being used in the online images, try printing out the colored demonstration patterns and making your own paper masks. You will see that the only “trick” involved is being provided by your own brain. This is why even a perfectly aligned display device can indeed look different than a calibration report might indicate. Conflicting viewing environment conditions, such as the wrong lighting or colored room surfaces within the observer’s field of view, will ALWAYS distort how a video image appears to the viewer. No calibration instrument can measure this function of the brain. It’s simply a perceptual issue.

Best regards and beautiful pictures,
Alan Brown, President
CinemaQuest, Inc.
SMPTE, ICA, PVA, THX, ISF, Lion AV Consultants

“Advancing the art and science of electronic imaging”

###

Enjoying the news? Sign up now for the Creative COW Newsletter!

Sign up for the Creative COW newsletter and get weekly updates on industry news, forum highlights, inspirational tutorials, tips, burning questions, and more! Receive bulletins from the largest, longest-running community dedicated to supporting professionals working in film, video, and audio.

Enter your email address, a first and last name, and let us know what you’d like to see more of in the message!

Responses

We use anonymous cookies to give you the best experience we can.
Our Privacy policy | GDPR Policy