HDR: Seeing is believing
High Dynamic Range (HDR), refers to high brightness display technology that utilises the progresses made in camera technology – allowing video to be captured with rich colours in both dark and light areas: producing video with higher contrast than ever possible before.
HDR can produce startling images. Images of such high quality and solidity, that you feel as if you are seeing the scene with your naked eye. With HDR seeing truly is believing.
Sony developed this technology both in response to filmmakers – whose strong desire to express themselves through this new technology is increasing rapidly: and, also, because there was, until recently, no master monitor on the market that could provide an accurate HDR display.
The master monitor – a standard device that always produces the same image, wherever you are and measures final quality control – is, therefore, an indispensable item for filmmakers.
For almost 40 years, Sony’s master monitors have been highly regarded among filmmakers as the go-to product. From Trinitron CRT to OLED – and, now, through creating standard devices compatible with High Dynamic Range – we have constantly evolved our technology, to meet the high standards customers have come to expect from Sony.
Developing the new BVM-X300 Monitor: "A monitor like a mirror"
The first of the TRIMASTER EL monitors arrived back in 2011. The fundamental principles of this award-winning series have always been accurate colours, precise picture and extraordinary reliability.
With a technology philosophy based on these 3 key principles, Sony began its development of its OLED display Panel Super Top Emission.
Feedback from customers is always a principal driver for new developments at Sony. The development of the BVM-X300 was no different, and the wish-list from our customers of an HD OLED master monitor included, “recreate perfectly the real image”, and, “a monitor like a mirror.”
The goal was to perfect a display that, “added nothing, took nothing away, showed the input signal exactly.” There were a mountain of challenges to overcome: from enlarging the OLED display to 30 inches, increasing resolution to 4096 x 2160; to making the display drive up to 60Hz and including Digital Cinema-spec Colour Space (DCI-P3). In addition, while aiming to achieve the fullest possible compliance with next generation broadcast and filmmaking regulations such as ITU-R BT.2020, there was also a commitment to realise an HDR display with notable high brightness, through EOTF (Electro-Optical Transfer Function), that would support S-Log 3 and SMPTE ST20842 (supported from ver.1.1).
Sony’s OLED display technology explained
Sony’s OLED displays comprise a TFT (Thin Film Transistor) layer that drives each pixel, a glass layer and an electrode/light emitting layer, sandwiched, between the two. The main difference to a liquid crystal display is that no backlight is needed since the device itself can produce light.
Due to this key difference with liquid crystal displays, when a ‘black’ signal is sent, a ‘true black’ can be shown and accurate reproduction of even dark colours is possible. Moreover, the reaction speed when the input signal level changes is far quicker and moving images are comparable with conventional CRT displays.
Display construction cross section
Reproduction of brightness versus input signal
Response speed diagram and video feature image
Range of colour reproduction versus input signal
Improved colour space and product lifetime
In order to maximise light emission a, ‘top emission’, construction is employed on the TRIMASTER EL – whereby the light emitting layer does not emit light to the TFT layer, but only to the glass layer.
This construction not only reduces energy use, but makes it easier to produce high brightness, lengthens the product’s lifetime and limits the burning phenomenon. Moreover, by employing a micro-cavity construction that achieves both high brightness and a wide colour space, and a colour filter (CF) with the glass layer, the OLED display has a remarkably improved colour space.
Utilising this wide colour space technology, the green OLED in the HD display was improved and the design target contained in the DCI-P3 digital cinema standard was met. In addition to addressing the colour space specifications of the next generation broadcasting standard, ( ITU-R BT.2020), the UHD display also supports Sony’s own S-Gamut3 and S-Gamut3 Cine standards which greatly exceed print film colour space and accurately reproduce colours.
The UHD display also complies with the previous ITU-R BT.709, EBU and SMPT-C broadcasting standards and can be used for a range of applications in broadcasting and filmmaking such as monitoring.
Advantages of micro-cavity structure and colour filters
Colour gamuts of BVM-X300
4K OLED Master Monitor
OLEDs are light-emitting devices that can display ‘true black’, and because the brightness of each pixel can be controlled, they give extremely high contrast – and are an excellent match for High Dynamic Range.
Achieving HDR on OLED was a technological challenge with many obstacles to be overcome, one by one, by Sony’s Scientific and Technical Academy Award® winning Research and Development engineers. Thanks to their work and our customers input, it is now possible to express new creative content more richly than ever before, with a display that can show light and dark images with no crushed shadows or clipped whites in a way that previous monitors could not achieve.
However, the creative content industry does not stand still – and neither does Sony. Continuing to work alongside our customers, we to look forward to the new challenges in the world of filmmaking.