In the six short years since 4K UHD TVs started appearing with high dynamic range (HDR) capabilities, HDR TVs have become the displays of choice for watching the latest HDR movie blockbusters and streaming series. It helps that prices have also plummeted in the last year, with a few 85″ HDR TVs now selling for under $1,000, and many 55″ models available for under $500!
By now, the idea of showing off your best photos and videos in a more compelling and realistic manner on a large HDR TV has probably crossed your mind. But that’s not as easy as it sounds, or as easy as it currently is with any Standard Dynamic Range (SDR) TV. The reason? In order to reap the benefits of the wider color gamut, higher contrast ratio and improved shadow and highlight details you can get from HDR TVs, the content you send to it must be specifically color-graded, tone-mapped and formatted according to basic HDR10 standards.
Otherwise, an HDR-capable display will default to one of its SDR modes, and even if you manually turn on its HDR mode, improperly formatted photos and videos will look significantly under-exposed.
it’s possible – and relatively easy – to create photo slideshows and videos that take advantage of HDR TVs’ stunning image quality
Now for the good news. Despite a few reports to the contrary, it’s actually possible – and relatively easy – to create photo slideshows and videos that automatically turn on a TV’s HDR abilities and take advantage of its stunning image quality. This step-by-step tutorial will show you how to go about it using a fairly recent Mac computer and Apple’s Final Cut Pro.
Note that the tutorial focuses on videos, and movie slideshows of still images. Adobe is currently previewing HDR support and editing tools for photos in Adobe Camera Raw, but the still-image formats it can output aren’t yet well supported, making distribution and viewing of HDR photographs tricky. Because HDR technology originated in the video industry, support for HDR video files is much more robust, meaning that HDR-capable tablets, smartphones, laptops and TVs can often replay HDR10 video content, and YouTube’s support for HDR makes online sharing of slideshows simple and reliable.
Step by step guide
Step 1: Setting up your workstation
Since the final destination for your creations will be an HDR-capable display, a dual monitor setup – with one screen being a 4K UHD HDR TV of any size – is the ideal editing setup. This allows you to use an SDR computer monitor to display the controls, library, and timeline of Final Cut Pro, while the attached TV lets you view the image preview window with as much detail as possible – even in a room with moderate light levels. The HDR TV used should have a peak luminance rating of 400nits (cd/m2) or higher, have 10-bit processing and output, and cover approximately 100% of the AdobeRGB or DCI-P3 color gamuts.
How do you determine the peak luminance, bit depth, and color gamut coverage of your HDR mastering display? You can simply rely on the manufacturer’s feature specs (typically found here). Most monitor calibrators can also be used to take a peak luminance reading of a white target on your screen. Note: many HDR TVs can only deliver peak luminance ratings on small target areas, and not at full screen, so make sure to measure a small target.
Activate the TV’s HDR mode either via the remote control or the Mac, but not both.
Since the HDR modes found on most new HDR TVs are pre-calibrated to 6500k and the DCI-P3 color space, they don’t need to be calibrated or profiled to be usable.
If your HDR TV can be set to its HDR mode using its remote control, do so. If not, you should be able to activate it from current Macs – these can determine if an HDR TV display meets HDR10 standards by reading the display’s embedded Extended Display Identification Data (EDID). If it’s compatible, a check box will appear in the Mac’s ‘Display settings’ dialogue that allows you to activate the display’s HDR mode. Activate the TV’s HDR mode either via the remote control or the Mac, but not both.
Step 2: HDR Project Settings in Final Cut Pro
Prior to opening and editing in Final Cut Pro it helps to prepare your photo and video files. For photo slideshows, the best results will be achieved by using original Raw files, or those that have been retouched and saved as 16-bit TIFF or 16-bit DNG files in either the AdobeRGB 1998 or DCI-P3 color spaces. Final Cut Pro recognizes several native Raw file formats, so you might be in luck and not have to convert them. Hopefully, any JPEGs you absolutely need to use were originally saved in-camera using the AdobeRGB profile setting. That could improve results by revealing colors that may have been captured by your camera but aren’t visible in the sRGB (rec.709) color space – just like AdobeRGB JPEGs make better prints than sRGB-profiled JPEGs.
When creating HDR movies, use your original video files or highest-quality conversions. Many cameras can now record video in 10-bit using Log, HLG or PQ curves, while others can record a Raw video stream to external drives that encode the stream as ProRes RAW. All of these record video images with the highest bit-depth available from the camera sensor, enabling wider tonal ranges, wider color gamuts and finer adjustments in FCP. On the down side, these files tend to take up more storage space due to increased bit depth and reduced compression, and in some cases may require conversion to a format recognized by FCP.
The next step is to create a new wide-gamut color library and an HDR project in FCP, using the settings recommended below:
Once your project is created, multiple images and movie files can be dragged to the timeline at once, and will simultaneously appear in the library. Ignore import warnings stating videos might not meet PQ standards or be tagged with Rec.709 profiles. If, at this point, your connected HDR TV has been set to its HDR mode, normally-exposed images should appear fairly dark but visible in FCP’s main view window on it. Otherwise they will appear overexposed until the HDR TV is put into its HDR mode.
If your photos were saved as 16-bit TIFF files using Adobe’s new Camera Raw HDR toolset, they should appear identical in FCP’s HDR monitor window, or only require minor adjustments to achieve your color and tonality intent. The advantage of performing your color and tonality adjustments in FCP is that the original images are not changed, while files adjusted and saved as HDR images using Adobe Camera Raw retain their edits and will not appear normal on SDR monitors.
Tip: To speed up the import process and save space on your hard drive, go to FCP’s Preferences/Import panel and select ‘Leave Files In Place.’ This prevents FCP from copying those files into a separate project folder. (If you’re using files stored on a camera’s memory card, don’t select that option.)
The advantage of performing your color and tonality adjustments in Final Cut is that the original images are not changed, while files adjusted and saved as HDR images using Adobe Camera Raw retain their edits and will not appear normal on SDR monitors.
While not required, you can help ensure compatibility with a variety of HDR TVs, especially those boasting higher peak nit ratings than your HDR TV mastering display, by adding metadata about your monitor’s capabilities. This data remains embedded in the final movie file, and can be read by other HDR TVs and programs like Apple’s QuickTime. Theoretically, brighter HDR TVs can use that data to adjust their tonal curves to improve the image quality of your movies.
To add this metadata, click on your project’s name, then on the Info icon (see below). Select P3 and D65 from the drop down menus, and fill in the luminance fields with the manufacturer’s information or with measured values of your specific HDR monitor. MaxCLL (maximum brightness of any part of the content) should be set to your display’s peak luminance value, while MaxFALL (highest average frame brightness that occurs in the content) should be set to a generic 100 (unless you’re advanced enough to figure out your project’s MaxFALL rating. There’s not space enough to explain how to do that here.)
Step 3: Adjusting exposure and color in Final Cut Pro
You can now use all of the color, contrast, saturation and exposure correction tools available in FCP to adjust your darkened photos and video clips until they have the brightness, color saturation and contrast that meets your vision and intent. Begin by adjusting exposure using FCP’s Color Board, as shown below.
In addition to the Color Board, FCP also includes several color and tonality adjustment tools for fine-tuning and maximizing the impact of your photos and videos in HDR. The RGB Color Curves tool, familiar to most photographers, allows you to add adjustment points throughout the tonal range for Global and RGB color fine-tuning beyond the capabilities of the Color Board. Videographers may be more familiar with the Color Wheel adjustment tool (see below), which also allows for finer adjustments of both still photos and videos.
Exporting from FCP: When your editing is done, select Render All and wait for the rendering to finish before exporting the movie. The quickest way to process and export you movie is to select File > Share > Apple Devices 4K, then select the HEVC 10-bit Video Codec in the settings panel (see screenshot below). After hitting Next, you can save the processed file to the location of your choice. For sharing options, see Step 5.
|Fastest export option: Click File > Share > Apple Devices 4K and select the ‘HEVC 10-bit’ Video Codec option under settings.|
Step 4: Optional compressor settings
As an option for those who have it, Apple’s Compressor software allows you to process multiple HDR slide shows and videos at once in the background, as well as use other Macs on your network to share that processing load. It also allows you to adjust HEVC compression and quality settings to a greater degree than when using FCP’s export preset. You can send unprocessed files directly from FCP to Compressor by selecting File > Send To Compressor > New Batch. Compressor will open. FCP can then be closed to free up RAM, or you can continue to work in FCP while Compressor processes and stores your video.
In Compressor, drag the ‘Apple Devices 4K (HEVC 10-bit)’ preset from the left Settings column onto your project name. A new export file name will appear in the box under your project with ‘Apple Device 4K-HEVC’ added to the name, and that name can be modified in the General Properties window along with the project description, as shown below.
Since the default HEVC data rate that Compressor chooses is usually a bit higher than required, consider reducing it a bit to create smaller files. You can also chose ‘Faster (Standard Quality)’ setting in the Encoder Type and the Bit Rate settings to save a ton of processing time (this setting is similar to the one used by FCP). There may be subtle differences in the final results between these choices, with finer tonal gradations, slightly higher color accuracy, and slightly smaller file sizes produced by the Slower (Higher Quality) default. However, the time saved in the Faster mode may be well worth it, especially when creating a draft or a project you plan to upload to YouTube and other streaming services.
When you select ‘Start Batch,’ another window will open showing the progress of the project’s encoding as well as info on any other projects you’ve previously processed.
Step 5: Sharing your files
Both FCP and Compressor save your processed slide shows and movies with the name you’ve chosen followed by an .m4v extension. Unfortunately, the majority of non-Apple playback devices, including many HDR TVs, do not recognize that extension, so you can’t just load the movie file onto a USB drive and insert it into your HDR TV for playback. There’s no way to modify that .m4v extension in either program (as far as I know) before you process and store it. However, once the file is saved, you can simply select the .m4v extension part of the file name, change it to .mp4, and hit Enter. A warning will pop up asking if you want to change the extension to .mp4; go ahead and confirm it.
These files can also be uploaded to YouTube and other streaming video services that accept HDR10 compatible files. Note, however, that most streaming sites will convert and re-compress those files to increase playback speeds, and some fine details in shadow areas, saturated colors, and highlights may suffer as a result. They’ll still look better than SDR movies on an HDR TV, but the highest overall image quality will come from playing back the original files from a USB drive inserted into either an HDR TV or a 4K UHD BluRay player attached to the TV.
Also, if you have the VLC app on your phone or PC, it will play back the .mp4 extension files after applying an HDR-to-SDR tone curve adjustment, so they’ll appear fairly normal on those SDR displays. Quicktime also does that when you open the HDR files on a Mac (whether you change the extension or not), but in both cases there will be visible banding issues due to posterization as each 8-bit program clumsily tries to display a 10-bit image on an SDR screen.
Step 6: Fine-tuning in and for your playback devices
You’ve now learned how to color-grade, adjust, export and store your photos and videos so they will appear with wider color gamuts and image quality on any HDR TV or compatible device. However, the individual controls found on most HDR TVs also allow you to further adjust color saturation, color temperature, contrast, and sharpness when playing HDR videos.
Most HDR TVs are calibrated at their default settings, so if your slideshows look a bit off on another HDR TV, consider resetting that TV’s saturation or color temperature parameters. If that doesn’t help – and your projects also look off (bad color, lousy contrast, etc.) on the majority of HDR TVs and displays – then look at your files using Quicktime’s Movie Inspector and make sure your movies have been stored with the right bit depth and metadata (see the screenshot above) to turn on the HDR modes of HDR TVs.
If your highlights are washing out or your shadow areas show little detail on most HDR displays, you can also try using FCP’s Waveform Monitor tool while adjusting each image. When FCP is set to wide color gamut and the Rec.2020 PQ workspace, the Waveform monitor scale is shown in nits, not in IRE units as with SDR. That means you can limit the peak whites (specular highlights) to 1000 nits or below so they look good on the majority of HDR TVs, and also ensure that your shadow areas are not clipped, limiting important shadow details.
As mentioned earlier, editing programs such as Adobe Camera Raw now allow you to adjust individual photos so they will look great on your HDR TV. However, in order to view HDR-graded photos using that program or others that include an HDR Tone Mapping option, you’ll have to manually turn on the HDR mode on your display (via its remote or Apple’s Display Control Panel).
As yet, there’s no standard way to embed the metadata in still photo files that will automatically turn on a display’s HDR mode. If your goal is to showcase your photos and videos in glorious HDR on a wide array of devices with minimal fuss, then creating an HDR movie file with all the key ingredients is your best, most sharable option.
Michael J McNamara