# Standard-dynamic-range video

Standard-dynamic-range video describes images/rendering/video using a conventional gamma curve, and therefore presenting a dynamic range that is considered standard, as opposed to high-dynamic-range video.[1] The conventional gamma curve was based on the limits of the cathode ray tube (CRT) which allows for a maximum luminance of 100 cd/m2.[2][3] The first CRT television sets were manufactured in 1934 and the first color CRT television sets were manufactured in 1954.[4][5]

## Technical details

The dynamic range that can be perceived by the human eye in a single image is around 14 stops.[1] SDR video with a conventional gamma curve and a bit depth of 8-bits per sample has a dynamic range of about 6 stops.[1] Professional SDR video with a bit depth of 10-bits per sample has a dynamic range of about 10 stops.[1] Conventional gamma curves include Rec. 601 and Rec. 709.[6] The linear part of the conventional gamma curve was used to limit camera noise in low light video but is no longer needed with high dynamic range (HDR) cameras.[6] An example of a conventional gamma curve would be Rec. 601:

${\displaystyle E={\begin{cases}4.500L&L<0.018\\1.099L^{0.45}-0.099&L\geq 0.018\end{cases}}}$

## Limitations

While conventional gamma curves are useful for low light video and are compatible with CRT displays they have a limited dynamic range.[1][2] A transfer function that is closer to Weber's law allows for a larger dynamic range, at the same bit depth, than a conventional gamma curve.[1] HDR standards such as Hybrid Log-Gamma (HLG) and SMPTE ST 2084 allow for a larger dynamic range by using a different transfer function.[1][2] HLG is compatible with SDR displays.[7]