Ask the Experts with Dolby

Bob Pank#

Author: Bob Pank#

Published 1st June 2012


Q: Dolby has recently been making waves in imaging with its PRM-4200 Professional Reference Monitor, but isn’t Dolby an audio company?
Dolby has been involved with imaging technology for years, beginning with Dolby® Digital Cinema in 2005, then launching Dolby 3D for the cinema in 2007, and then in 2010 we introduced the Dolby PRM-4200 Professional Reference Monitor. Dolby has a long history of working with professionals in the content creation community, and this relationship allowed the company to understand the changes in display technology that were causing problems for the postproduction community.
When Cathode Ray Tube (CRT) professional monitor production ceased in 2005, it created a real dilemma for users requiring critical viewing who, until then, had relied on the faithful Grade 1 CRT monitors, which were the reference standard.
That’s where Dolby came in. We saw the opportunity to use our considerable expertise and worked closely with the industry to develop a viable replacement product for the CRT. Dolby developed the PRM-4200, a 42 inch (diagonal) LCD/LED flat panel display, to fill the gap left by the CRT. The Dolby Professional Reference Monitor is the first flat-panel monitor that truly betters the CRT’s performance, delivering true blacks, exceptional dark detail, high contrast, and enhanced colour gamut. We believe it is one of the most consistent, accurate reference monitors for creating any type of entertainment content.
That’s why many in the industry are saying it has become the new standard for reference monitors.
Q. One of the most striking things about the PRM-4200 is its size compared with other grading quality monitors. Why did you choose to make it a 42 inch panel?
It’s a matter of the changing needs of professionals and the market. Whilst the old Grade 1 monitors are still being used for critical evaluation of image quality for movie and broadcast applications, the consumer viewing the same content on their TV at home has moved away from the CRT to larger LCD and Plasma TVs with an average size of around 40 inches.
So, working with industry professionals, we looked at flat panel options for professional use and we decided that a 42 inch panel would be the optimum size. This is the size closest to what most consumers are watching TV and movies on at home.
Q. What makes the Dolby Professional Reference Monitor so different?
The thing that makes the PRM-4200 genuinely different is not just the incredible quality, but also the amazing flexibility it has to emulate virtually any other display device, from consumer LCD or plasma TVs, to a Grade 1 CRT, and through to DLP projector in the DCI colour space. This means the Dolby Professional Reference Monitor can be used for DI-colour grading, without the use of a digital projector.
As for standards, it fully supports Rec709 and DCI-P3 colour space, whilst allowing the display of all high-definition formats via HD-SDI, and 2K content, either scaled or pixel-by-pixel. The monitor supports the luminance level required for DCI, from 48 cd/m , through to 120 cd/m for Rec709.
Dolby has further extended the performance of the Grade 1 monitor by being the first monitor to display a full 12-bit input in either RGB or XYZ format via dual link HD-SDI. It of course supports standard 10-bit inputs in component or RGB format via HD-SDI.
And because it can emulate virtually any other display device, the colourist can see for themself any chosen delivery format without leaving their seat. This means the Dolby monitor replaces the need for an array of other monitors to check content.
Q. How does Dolby achieve this level of performance?
This is achieved by Dolby’s combination of an LED backlight with an LCD front display panel. Dolby has a patented dual modulation process that provides unprecedented black levels, along with precise colour accuracy at all luminance levels, and also enables very wide dynamic ranges to be achieved.
Dolby’s LED backlight unit comprises 4,500 LEDs arranged in 1,500 RGB LED triads that directly illuminate the LCD panel. The output of each R, G, and B LED is modulated on a frame-by-frame basis with respect to the image content for each frame. When the image requires that any portion of the screen goes dark, the LEDs are dimmed, which means that no light will pass through the LCD to the viewer. The result is absolute black levels that challenge the limits of most instruments to accurately measure this.

The second element of dual modulation is the LCD panel itself, which is modulated in real time based on a complex algorithm composed of a variety of matrix and 2-D filtering operations. The modulated LCD, together with the modulated backlight unit forms the dual modulation process that is directly responsible for the amazing image quality.
Dolby has extended the maximum luminance range of a professional device from the Rec709 standard of 120 cd/m up to an amazing peak luminance of 600 cd/m . This Dynamic Reference mode not only allows viewing in high ambient environments, but also provides the ability to view the full high dynamic range of the latest high-end digital cameras, like the ARRI Alexa, Red Epic, and Sony F65.
Q. So what about emerging trends and future formats?
The PRM-4200 already displays HDR content from the latest high-end digital cameras like the ARRI Alexa, this allows the user to view all 14 spots of exposure that the Alexa can provide. No other professional display can do this in the market today.
At NAB last month, we also announced that we have added support for content shot at 48 frames per second (fps). The PRM-4200 already supports 50/60 fps, but with the extended support for 48 fps is now set to be part of the move towards high frame rate movies. With Directors like Peter Jackson using 48 fps for his upcoming movie The Hobbit, and James Cameron advocating 60 fps capture and display for digital cinema, this is another future-proof feature that has been built in to the PRM as standard.
The PRM is now well-placed to become the industry standard device for AMPAS® ACES workflow. This new standard from AMPAS has a wide colour gamut and extended high dynamic range. Dolby has developed its own ACES ODT (Output Display Transform) to allow content to be viewed in HDR and P3 colour space.
Q. So who is investing in the Dolby Pro Monitor?
It is really now setting the standard in the postproduction communities globally. In the UK, the likes of MPC, The Mill, Envy, Prime Focus, The Farm, Films@59 and Deluxe are just some of the leading names to have invested in multiple units of the PRM-4200.
The Dolby Professional Reference Monitor has also recently been used on a number of high-profile Hollywood movie projects, including David Fincher’s acclaimed Girl With the Dragon Tattoo, as well as War Horse, Mission Impossible: Ghost Protocol, and most recently Mirror Mirror.

Tags

dolby

Related Listings

Related Articles

Related News

Related Videos

© KitPlus (tv-bay limited). All trademarks recognised. Reproduction of this content is strictly prohibited without written consent.