Questions about HDR / SDR.

[kris.smith]

Lightroom Version Number

15.1

Operating System

1. macOS 26 Tahoe

Hi everyone, I hope you're all well and thanks for having me here!

I edit photos on LRC using a preset LUT. I like the look of it but it caps the maximum brightness which can't be overrided. In other words, if I increase exposure, highlights etc. I can't get full exposure from the image.

If I press the HDR button on my SDR monitor, the resulting image is exactly as I'd like it to be. However, I can't seem to find a way to export this resulting image to an SDR format that maintains the exposure I see on screen. As soon as I export, I either get an SDR image with exposure capped, or an HDR image (depending on export settings). I basically want the exact same result as if I grabbed part of the screen (when the HDR button is pressed) and saved this to an image.

Is there any way round this within LRC, or any tools I could use to get the result I want.

 

[clee01l]

HDR images are different from SDR images. A JPEG in JPG format will always be SDR. If you want to save in HDR format you need to use the newer JXL or AVIF format. An HDR image saved is actually two images files in one. An SDR image for that apps that can not handle HDR and an HDR format for those that can. For HDR processing in Lightroom Develop, you can process in HDR and compare what you have by looking at it in SDR .

Monitors that claim HDR may not be true HDR. Only monitors that can produce 600 nits brightness or higher can display HDR with a noticable luminance range. "SDR formats are able to represent a maximum luminance level of around 100 nits. For HDR, this number increases to around 1,000–10,000 nits". Since you and your monitor may not be the only viewer of your image, you need to produce an image that other viewers and other monitors can handle. HDTVs produced after ~2020 usually can display HDR. These will have specs that list HDR10, HDR10+ or Dolby Vision. However the App used to display may not support JXL or AVIF format.

FWIW, I have two 32"HDR monitors by ASUS ProArt. One is 1000 nits and one is 1600nits. My third monitor is a 27" SDR monitor of 400nits. The same image viewed on each have a striking difference.

 

[Jim Wilde]

HDR images are different from SDR images. A JPEG in JPG format will always be SDR. If you want to save in HDR format you need to use the newer JXL or AVIF format.

That's recently changed, Jpeg does now support HDR. I can't remember exactly when that change was made, but it definitely can now display HDR images. We just need to ensure that the "HDR Output" option is checked in the Export dialog's File Settings panel.

 

[jrobnz]

That's recently changed, Jpeg does now support HDR. I can't remember exactly when that change was made, but it definitely can now display HDR images. We just need to ensure that the "HDR Output" option is checked in the Export dialog's File Settings panel.

That's correct and nearly all browsers will display JPG, or in most cases AVIF, in HDR if the monitor supports it. It works by storing a "gain map" along with the normal SDR image within the JPG or AVIF. The gain map is used to produce the HDR image and the browser will tone map it correctly to match the luminance range of the monitor.

But it's not possible to get what you see in HDR to be the same in an SDR image. SDR doesn't have the dynamic range and anything beyond will be clipped to pure white. Similarly, anHDR image cannot be printed to look the same because you can't be brighter than the paper's white.

When you are editing an HDR image (with the HDR button enabled) you control the maximum luminance with the range slider which recently was changed to default to 2 stops. Increase that to 3 or 4 depending on your monitor. You also have a section of controls activated with you choose "Visualize SDR" and these sliders control what the image will look like on an SDR monitor or a browser, website or app that doesn't support HDR.

I think Greg Benz probably has the best website for learning about HDR development and how to display them at https://gregbenzphotography.com/hdr/

 

[kris.smith]

Thanks for the replies everyone. I was possibly unclear in what I was hoping to achieve. I just want an export that looks the same as it does on my non-HDR monitor when the HDR button is pressed. In other words, everything over the SDR clipping point is clipped in the final exported image. I have been messing about with the visualise SDR controls the past day and that does seem to get me very close to what I want although not identical.

Cheers!

 

[jrobnz]

HDR isn't all or nothing. It's anything brighter than SDR clipping point. Perhaps your monitor isn't full HDR (eg. +4 stops above SDR) but does have some ability above SDR. But I would think you would need to enable HDR in the MacOS display settings to achieve this or else MacOS will clip it

Post a screen shot of the histogram when you are in HDR mode and have the image the way you want it

 

[Gnits]

Lots of useful information here.

To help me further... how do common devices now rate in terms of HDR display ability. Eg Mobile Phones, iPads, current versions of laptops, etc. I know there is a huge population of legacy devices .. but if current popular devices have degrees of HDR compatibility / capability then I can form a view myself on relevance of HDR to my workflow.

 

[clee01l]

That's recently changed, Jpeg does now support HDR. I can't remember exactly when that change was made, but it definitely can now display HDR images. We just need to ensure that the "HDR Output" option is checked in the Export dialog's File Settings panel.

Thanks, Good to know. Now will apps that read JPEG files (such as those on a Smart TV) automatically use the HDR or will they need some revision to add that capability?

 

[clee01l]

Lots of useful information here.

To help me further... how do common devices now rate in terms of HDR display ability. Eg Mobile Phones, iPads, current versions of laptops, etc. I know there is a huge population of legacy devices .. but if current popular devices have degrees of HDR compatibility / capability then I can form a view myself on relevance of HDR to my workflow.

Newer Apple iPhones, iPads and Apple laptops are HDR capable out of the box.
Specs for current models are:
1000 nits max brightness (typical)
1600 nits peak brightness (HDR)

While the device has the capability, I am concerned about the image JPEG format that Jim says can now export with "HDR Output". How is the JPG standard (with "HDR Output") different from the JXL filetype? Does the App used to display the image need to differentiate SDR and HDR data in the JPG filetype? After experimenting with the HDR processing in Lightroom (and buying first one then a second HDR monitor), I discovered that my HDR efforts only seemed work in my Lightroom app. Other apps did not recognise JXL formated images and my HDR10+ HDTV could not recognize the JXL file type in a slideshow. At that point I abandoned HDR processing in Lightroom because it did not buy me any advantage outside of Lightroom. Now that I know JPG files types can be exported with "HDR Output", I'll have to revisit my workflow to slideshows on my HDTV experiment.

 

[Gnits]

Thank you.. so very much evolving…. I will watch that space… I suspect Adobe are laying the groundwork and a WIP situation.

 

[Jim Wilde]

While the device has the capability, I am concerned about the image JPEG format that Jim says can now export with "HDR Output". How is the JPG standard (with "HDR Output") different from the JXL filetype? Does the App used to display the image need to differentiate SDR and HDR data in the JPG filetype?

As a quick and dirty experiment, I just exported the same HDR image in JPG, JXL & AVIF formats, using the same settings. The JPG was twice the size of the AVIF, with the JXL in between. In terms of compatibility: using Preview, both the JPG and AVIF display as HDR (with no discernible difference), but the JXL was only displayed in SDR mode. Using the Chrome browser, both the JPG and AVIF were displayed in HDR (again, no visual difference), but the JXL would not open. So for me, that indicates that JXL is not yet suitable, but of the other two formats AVIF is much more efficient.

 

[jrobnz]

Newer Apple iPhones, iPads and Apple laptops are HDR capable out of the box.
Specs for current models are:
1000 nits max brightness (typical)
1600 nits peak brightness (HDR)

While the device has the capability, I am concerned about the image JPEG format that Jim says can now export with "HDR Output". How is the JPG standard (with "HDR Output") different from the JXL filetype? Does the App used to display the image need to differentiate SDR and HDR data in the JPG filetype? After experimenting with the HDR processing in Lightroom (and buying first one then a second HDR monitor), I discovered that my HDR efforts only seemed work in my Lightroom app. Other apps did not recognise JXL formated images and my HDR10+ HDTV could not recognize the JXL file type in a slideshow. At that point I abandoned HDR processing in Lightroom because it did not buy me any advantage outside of Lightroom. Now that I know JPG files types can be exported with "HDR Output", I'll have to revisit my workflow to slideshows on my HDTV experiment.

HDR is supported on all Apple XDR displays on every current Mac computer and iPhone. It works right out of the box on Apple. On Windows it works too but isn't quite right out of the box but displays vary of course. It is in many monitors at various levels especially gaming monitors and Asus ProArt. For software support it is in all mainstream browsers as well as Instagram, Wordpress (with some exceptions) and many others.

The JPEG HDR format is implemented through a secondary image containing a gain map. The primary image is the SDR as usual so any software that doesn't understand HDR still displays the SDR image as normal. To produce the HDR the gain map is used as a multiplier against the SDR image and is then tone mapped to match the monitor's capabilities. What this means is a JPG with an HDR image can be viewed anywhere today at whatever level the hardware supports. AVIF works the same way. All mainstream browsers support JPG HDR. Most also support AVIF. Only legacy or special-purpose browsers don't. This means a large majority of devices and browsers currently have support and it automatically falls back to SDR if they don't. But JXL isn't widely supported by browsers and probably won't be.

The only trick is to make sure that the HDR gain map doesn't get stripped by any software strips EXIF data such as cloud app uploads. Otherwise it just works.

To lean more about this and download a very handy gain map display application check out https://helpx.adobe.com/camera-raw/using/gain-map.html The gain map demo app lets you view JPG's and see the actual base image, adaptive image (based on your display and it's current brightness) as well as the gain map itself.

 

[jrobnz]

Thank you.. so very much evolving…. I will watch that space… I suspect Adobe are laying the groundwork and a WIP situation.

It's not really a WIP for Adobe as they've already done it. There is full support in LrC, Lr and PS. The only WIP is for certain cloud apps to stop stripping the EXIF info for the gain map

 

[clee01l]

It's not really a WIP for Adobe as they've already done it. There is full support in LrC, Lr and PS. The only WIP is for certain cloud apps to stop stripping the EXIF info for the gain map

Thanks for reminding me about the gain map. I read and absorbed this concept when I first delved into HDR when first introduced to the concept by Lightroom. My brain search engine is not what it used to be...

 

[Gnits]

I agree… the gain map concept is very useful to know and the demo SDR /HDR links will be very useful. Thanks.

 

[Gnits]

I just posted this on a different discussion.

This is just posted by Greg Benz (from CES) and is a good primer for what is coming down the tracks re HDR..

Also amazing that monitors / TVs are likely to exceed AdobeRGB and P3 gamuts.

https://youtu.be/6v-Bk7nq5Vo?si=2-9lzxSewYbjhmz2

 

[John Forgan]

HDR is supported on all Apple XDR displays on every current Mac computer and iPhone. It works right out of the box on Apple. On Windows it works too but isn't quite right out of the box but displays vary of course. It is in many monitors at various levels especially gaming monitors and Asus ProArt. For software support it is in all mainstream browsers as well as Instagram, Wordpress (with some exceptions) and many others.

The JPEG HDR format is implemented through a secondary image containing a gain map. The primary image is the SDR as usual so any software that doesn't understand HDR still displays the SDR image as normal. To produce the HDR the gain map is used as a multiplier against the SDR image and is then tone mapped to match the monitor's capabilities. What this means is a JPG with an HDR image can be viewed anywhere today at whatever level the hardware supports. AVIF works the same way. All mainstream browsers support JPG HDR. Most also support AVIF. Only legacy or special-purpose browsers don't. This means a large majority of devices and browsers currently have support and it automatically falls back to SDR if they don't. But JXL isn't widely supported by browsers and probably won't be.

The only trick is to make sure that the HDR gain map doesn't get stripped by any software strips EXIF data such as cloud app uploads. Otherwise it just works.

To lean more about this and download a very handy gain map display application check out https://helpx.adobe.com/camera-raw/using/gain-map.html The gain map demo app lets you view JPG's and see the actual base image, adaptive image (based on your display and it's current brightness) as well as the gain map itself.

Thank you very much for the explanation and link to the Demo App. For the first time I'm beginning to understand how the HDR settings in LR work!

 

[clee01l]

Also amazing that monitors / TVs are likely to exceed AdobeRGB and P3 gamuts.
QUOTE]

DCI-P3 (Digital Cinema Initiative was developed for Transmissive Projected media (movies) and AdobeRGB is a generic CMYK Print standard for reflective media. It is nearly 30 years old.

Both standards exceed the capabilities of CRT monitors. And today’s crop of Monitors are still less (99%) than AdobeRGB and DCI-P3


Sent from my iPad using Tapatalk

 

[Gnits]

The focus of the short clip was the evolution and availability of HDR.

As an aside, I am glad to see more AdobeRGB screens (or wider than AdobeRGB) available, especially as I have a pending high quality hand made, hand printed, hand bound book project looming.

 

[clee01l]

The focus of the short clip was the evolution and availability of HDR.

As an aside, I am glad to see more AdobeRGB screens (or wider than AdobeRGB) available, especially as I have a pending high quality hand made, hand printed, hand bound book project looming.

I liked the Blogger's comments about using HDTVs for 'picture frames'. I moved into this townhome 7 years ago. Prior to the move, we took a trip to Santa Fe to visit the art colony there. I picked up an alabaster sculpture for the alcove on my landing and two very large oil and acrylic pieces for two walls down stairs. The living room has one other large wall which is suitable for the TV. While we do occasionally watch TV there, its main purpose has been to display my photo art. I have two more large HDTVs upstairs often used for the same purpose to display photos.

I was excited when Adobe introduced the JXL HDR image file type. But I was disappointed to discover that my HDTV slideshow app does not recognise this file type. Recently, I have learned in this thread that JPEGs can be saved with HDR content. I have yet to make a comparison test like Jim Wilde to see if my HDR 10+ HDTV can display HDR JPEG images.

 

[Gnits]

I agree… A lot of people are still vague on the whole HDR/SDR topic. The clip above may clarify where this stuff is now going (and rapidly).

Your example of using framed TVs for artwork is good.

Rec2020 as an achievable real world standard includes both P3 and AdobeRGB…

A lot of people are either moving from Win to Mac or iMac to Mac Studio … so there are a lot of people out there trying to figure out what screen to get. The Asus ProArt range gets a favourable mention in the clip… and while I am not looking for a new monitor or TV right now, been aware of Rec2020 standard will improve my understanding of products on offer.