What does hlg on Sony camera mean?

The full name of HLG is Hybrid Log Gamma, which is a high dynamic range HDR standard jointly developed by British BBC and Japanese NHK TV. Professionals from both countries work together to provide a simpler way to capture and make images with high dynamic range.

In camera shooting, HLG and HDR 10 are two commonly used standards of HDR. But HDR 10 standard is based on PQ rule. It uses the method of absolute brightness to display. While HLG is based on relative brightness.

HLG does not need metadata and can be backward compatible with SDR. Compared with HDR 10, its screen can be more beautiful even on the existing SDR display equipment, while HDR 10 is grayed out when it is displayed directly on SDR.

HLG can decode the high-light and low-light parts contained in HDR signal in two different ways, in which the low-light part uses standard gamma curve and the high-light part uses logarithmic curve. Although the image of HLG may look slightly different from the HDR image of non-HLG, it can indeed present the HDR effect. I.e. a signal processing method.

Extended data:

Sony's convenient HLG process:

Among many processes of HDR, Sony's convenient HLG process has obvious advantages in the production of HDR. Its advantage is that its ability to restore dark details is similar to that of BT.709, but because it is compressed, more details can be captured in high-light parts.

For Sony PXW-FS5 and PXW-Z 150, they can be upgraded to four new HLG modes, including HLG, HLG 1, HLG2 and HLG3.

HLG is an international standard, while HLG 1, HLG2 and HLG3 are optimized versions of Sony. Among these curves, HLG 1 has the best noise reduction performance, but the overall dynamic range is narrow, while HLG3 has a wide dynamic range, but the noise is large. HLG2 is in the middle and its performance is relatively balanced.

When shooting HDR with HLG curve, you can use a camera that supports this function, such as PXW-FS5 (firmware version 4.02) or PXW-Z150 (firmware version 2.02), to record high dynamic range images into a memory card. Achieve efficient and convenient operation from the beginning of shooting.

Then, you can edit with the same process as before, and import the HLG video directly into the existing non-editing system, such as the latest version of non-editing software such as Edius or Final Cut Pro. You don't need to adjust the gamma and color gamut, but simply edit it to generate the output. HDR images can be obtained directly without color matching, which greatly saves the time for later editing.

Moreover, Sony Z9D or A 1 series LCD TV can be used to monitor HLG images during editing, which can ensure the quality and improve the cost performance.

Looking at the overall situation, using Sony HLG to shoot and later, the whole process does not need complicated settings, so you can easily get started and get HDR images quickly.