DISPLAYCAL SETTINGS FOR 4K HDR GAMING FULL
DISPLAYCAL SETTINGS FOR 4K HDR GAMING CODE

Note that the APL (Average Picture Level) remains approximately consistent between the SDR and ST2084 HDR images, with just the contrast range and specular highlight levels increasing. The following histogram is a simplified view of the difference between a SDR (Standard Dynamic Range) image, and its PQ HDR equivalent. So the reality is that HDR should mainly add to the existing brightness range of SDR displays, so more detail can be seen in the brighter areas of the image, where existing SDR images simply clip, or at least roll-off, the image detail. This is consistent with the existing SDR standards, where running peak white at higher peak luma levels for daytime viewing, as is the case in most home lounges, is common practice.Īlthough the nominal nits value for HLG diffuse white will vary with the peak brightness of the display, a 1000 nit display will place diffuse white around 200 nits, similar to PQ based HDR, while a 5000 nits HLG display will have diffuse white around 550 nits, depending on system gamma (see later for info on HLG system gamma).

DISPLAYCAL SETTINGS FOR 4K HDR GAMING CODE

The BBC's HLG HDR standard uses 75% of the signal (input code values) range as nominal diffuse white, which is obviously an 'output nit variable' value, as the HLG standard is a 'relative' standard, not 'absolute' as with PQ.

DISPLAYCAL SETTINGS FOR 4K HDR GAMING FULL

This has since been adopted by the ITU's BT.2408 specification (actually 203 nits), which is 58% of the full PQ signal (input) level. However, subsequent evaluation of PQ based HDR imagery showed a better relative image was attained with a diffuse white around 200 nits. This meant that the Average Picture Level (APL) of a PQ HDR display would not be significantly different to a SDR display for most imagery. With PQ HDR, brightness above 100 nits was expected to be used for spectral highlight detail only. The PQ based ST2084 HDR specification originally defined expected reference white (nominal diffuse white) as being around 100 nits, which is basically the same as for SDR (Standard Dynamic Range) displays, as specified for mastering (grading) grade-1 applications. The Eizo CG3145 Prominence is one of the few HDR displays that can maintain a linear output brightness response to input signal brightness, due to the use of what is effectively a backlight per pixel. Only a small percentage of screen area can be HDR bright.

It has to be remembered that many HDR displays cannot maintain a linear output brightness response to input signal brightness changes, if the average area of the picture that is bright is high.

But, moving away from the expected application of maintaining the average picture level consistent with SDR will generate unexpected results, and what will be assessed by the final viewer as being of poor image quality. Obviously, during the grading process the colourist/DoP, and any other hanger-on that has input into the look of the final image, is at liberty to use the extended brightness range as they see fit. The biggest confusion with regard to HDR is that it is not attempting to make the whole image brighter, which unfortunately seems a common misconception, but aims to provide additional brightness headroom for spectral highlight detail - such as chrome reflections, sun illuminated clouds, fire, explosions, lamp bulb filaments, etc. Consequently, calibration for all is basically identical. Note: PQ HDR defines HDR10, HDR10+, and Dolby Vision, as all use the same target colour space - Rec2020 Gamut, with the same PQ EOTF. PQ based HDR - Dolby Vision, HDR10, & HDR10+.Some of the issues this page addresses are: While the Philips/Technicolor and EclairColor HDR formats are included as standard HDR format options within ColourSpace, they are as yet not widely in use, so have been omitted within this tech. This page focusses specifically on PQ & HLG HDR and what they mean for display calibration, image workflows and the end image viewing experience. This page highlights a number of such issues, and attempts to explain their associated potential benefits and problems. The problem with HDR is a general lack of understanding as to what the technical aspects of HDR really are, and what they actually mean to the end viewed image. For example, there is nothing to stop a standard gamut display (Rec709), with standard HD or even SD resolution, working with an HDR EOTF with high contrast range. In response, the UHD Alliance has released what is calls a definitive (for now) Ultra HD specification called Ultra HD Premium, while Eurofins have launched their 4K HDR Ultra HD Logo scheme, and yet more certifications standards abound, with more promised.Īdditionally, the individual aspects of the HDR specifications can, and often are, used in isolation. HDR has had something of a difficult birth, with different display manufacturers effectively defining their own HDR, specifications, based on HDR10, HDR10+, Dolby Vision, and HLG.

Displaycal settings for 4k hdr gaming