HDR Video: HLG vs PQ Formats Explained

What HDR transfer functions are

HDR video delivers a wider range of brightness between the darkest shadows and the brightest highlights than standard dynamic range (SDR). The way a camera maps light to a video signal is described by a transfer function, sometimes called an electro-optical transfer function (EOTF). Two transfer functions dominate HDR production: HLG and PQ. They both extend the range you can capture and deliver, but they define brightness in different ways, and that difference drives which one you should pick.

The camera you use already includes one or both formats as recording options. Changing from one to the other affects how the sensor's output is encoded, how much highlight detail is preserved, and how the file looks on different screens. If you have already spent time learning how video log and gamma curves influence exposure, the same mindset applies here. The transfer function is not a look applied on top of the image; it is the foundation of the file.

HLG: Hybrid Log-Gamma

HLG, or Hybrid Log-Gamma, encodes the lower part of the signal using a gamma curve that is compatible with SDR, and the upper part of the signal using a logarithmic curve that records HDR highlight information. That design means a single HLG signal can be viewed on an SDR display as a normal-looking image, or on an HDR display with the extra highlight detail revealed. You do not need to grade a separate SDR version for broadcast or live streaming.

That backwards compatibility is the reason HLG is the format most commonly associated with broadcast, live sports, and event work. In settings where you do not know which displays your audience will watch on, HLG is the safest choice. It also produces a file that is usable on a standard, non-HDR monitor while you are working on location, which makes exposure and framing checks easier. If you are shooting a live event with a 4K camera, HLG will give you an HDR signal that you can hand to a production switcher or a streaming encoder without building a separate SDR master.

There is a tradeoff. Because HLG is designed to be viewable on both SDR and HDR displays, it does not push the absolute brightness of a scene as hard as PQ can. The peak brightness is intentionally more conservative, since the same signal has to satisfy two very different display standards.

• Good for live production, event coverage, and broadcast
• No need to create a separate SDR master
• Easier to monitor on a regular non-HDR screen
• Milder peak brightness than PQ

PQ: Perceptual Quantizer

PQ, or Perceptual Quantizer, is an absolute luminance encoding system. Instead of a compromise curve, PQ maps signal values directly to specific brightness levels, measured in nits, up to a defined ceiling. The format was designed to match the way human vision perceives brightness differences, which allows it to maintain visible detail in both shadows and highlights without banding.

Because PQ is tied to an absolute luminance value, the display that shows it must be a true HDR display. A standard SDR screen cannot render a PQ signal correctly. It will look dark, washed out, or both. That is not a flaw in the format; it is a specification. PQ is built for streaming platforms that know the display will be HDR and can color-manage the output, and for film and television masters that are destined for an HDR grade.

When you record in PQ, you commit to a grading and delivery pipeline that is HDR-only. That suits short-form content published directly to streaming platforms, as well as archival masters where the goal is a definitive version of the image. It also suits scenes you want to be seen at a very high brightness, since PQ can reproduce much brighter highlights than HLG. If you are working on a video camera with a high-end dynamic range, PQ will let you put that range to use.

• Absolute brightness values, ideal for known-output platforms
• Wider usefulness in cinema and streaming masters
• Requires an HDR display for correct monitoring
• Brightest possible highlights

Which format should you record?

The choice starts with the output display. If the deliverable goes to a specific streaming service with known HDR requirements, PQ is the direct path. If you are delivering to a broadcast channel, a venue, or a client that does not specify HDR, HLG is more forgiving because it will degrade gracefully on older SDR sets.

There is no downside to choosing one format consistently across an entire project. Mixing HLG and PQ clips in a single timeline can lead to inconsistent highlights and makes the grading session more complicated. Choose one for the whole shoot, then lock it for post. If you are producing short content for social media, PQ gives you the brightest pop and matches what platforms expect from HDR uploads. For long-form or documentary work where you need a robust file that will look good on the most displays, HLG is the practical choice.

When you are not sure what the final output will be, recording with a camera that logs a wide dynamic range can give you flexibility in post. But for most producers, the easier path is to pick HLG or PQ at the time of recording and monitor in that format. As explained in the dynamic range article, the sensor's latitude matters more than the format you choose. The format preserves what the sensor captures; it does not extend it.

Monitoring and exposure in HLG and PQ

The way you expose in HLG differs from PQ because the two formats interpret the highlight region differently. HLG keeps more mid-tone brightness close to a normal video look, so a zebra set to just below the peak works well. PQ has a wider space between mid-tones and the peak, and the highlight region is where detail is preserved, so exposing for a protected highlight is safer.

An HDR monitor is not required for HLG; an SDR screen will show a usable image. For PQ, you need a true HDR display to judge the image at all. If your monitor does not show the format correctly, use the camera's histogram and waveform, because a mis-set PQ exposure on an SDR screen may look dark and you will be tempted to increase exposure, which pushes highlights into clipped and unnatural territory. Learn to read the histogram for the HDR format you record and trust the numbers over the preview.

Bit depth and wide color

HDR is usually paired with a wide color gamut, such as Rec.2020 or DCI-P3. The transfer function handles brightness, while the color gamut handles the range of colors. They are separate choices, but they work together in the camera's menu. Some cameras link the two by default, so choosing an HDR format also selects a wider color space.

To avoid banding in gradients, record HDR at the highest bit depth your camera supports. The relationship between bit depth and color precision is covered in depth in the bit depth guide. A 10-bit image is the minimum for clean HDR video; 8-bit HDR often shows visible contouring in skies and shadows. If your camera records in 10-bit over HDMI, the same clarity applies when you record externally. For more on the HDMI side, see the HDMI output guide.

Choosing a camera for HDR work

The camera body you choose matters less than its dynamic range and bit depth. Look for a camera that records 10-bit video internally in both HLG and PQ, or that supports one format cleanly in 4K and leaves headroom in the highlights. Many modern mirrorless and cinema cameras from Canon, Sony, Nikon, and Panasonic ship with an HDR menu. If your camera already has both options, you do not need to switch bodies to work in HDR.

You should confirm that the camera's HDR option actually changes the transfer function of the recorded file rather than just applying a picture profile. This is explained in the picture profile for video guide. When a camera offers a true HLG or PQ recording mode, the file contains the full dynamic range the sensor captured, and the option is documented in the specifications. A picture profile with a contrast curve named "HDR" is not the same thing.

If you are shopping for a new camera, compare the specifications of 8K cameras and 5K or 6K cameras to find which ones list HLG and PQ in the video section. You can also read the 4K video explained article to confirm that your resolution choice matches the delivery format.

What to pick for your use

Questions

Is HLG better than PQ for YouTube?

YouTube recommends HDR uploads in PQ because the platform converts or distributes in PQ for HDR playback. HLG files may be accepted but you will not get the intended brightness. For YouTube, record in PQ.

Can you convert HLG to PQ in post?

Yes, with a color management tool. But the conversion will not add brightness that HLG did not capture. The highlight range of HLG is lower, so a converted file may look less bright than a native PQ file.

Do you need an HDR monitor to work with HLG?

No, HLG is viewable on a standard SDR monitor. It is meant to be compatible with both. PQ, however, requires an HDR display to judge correctly.

Which HDR format gives more dynamic range?

PQ has a higher luminance ceiling and is designed to preserve bright highlights up to a fixed value. HLG preserves more mid-tone accuracy but is less aggressive at the top. Both provide more dynamic range than SDR.