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How to post HDR photos to Instagram and Threads from your RAW files
To post an HDR photo to Instagram or Threads, export it as a JPEG or HEIC with a gain map, upload it from a phone with an HDR screen, and check the result on that phone. The gain map tells HDR screens to show the bright parts brighter, and every other screen sees an ordinary photo. Platform support is real but has shifted from release to release, so test one post before you rely on it.
RAW files are a good starting point because they hold far more highlight information than an SDR screen can show. An HDR export puts some of that back: sunlit clouds, specular glints and lamps glow instead of sitting at flat white.
What is a gain map?
An HDR photo with a gain map is two pictures in one file:
- The base image, an ordinary SDR photo. Any app, browser or printer can read it.
- The gain map, a small greyscale image plus metadata that says how much to brighten each area, and up to how far, on a screen with HDR headroom.
An HDR screen combines the two and shows highlights brighter than its normal white. An SDR screen ignores the gain map and shows the base image. Apple puts it plainly in its WWDC24 session Use HDR for dynamic image experiences in your app: backward compatibility "is guaranteed because the file contains a SDR baseline fully decodable by older systems or SDR-only applications."
Why ISO 21496-1 matters
For years Apple, Google and Adobe each stored gain maps in their own way, and the three weren't interchangeable. ISO 21496-1 is the standard that unifies them. Greg Benz, who has tracked HDR support closely, explains the background in ISO 21496-1 gain maps: share HDR photos and lists the software that supports it: Apple's operating systems from iOS 18 and macOS Sequoia, Lightroom and Camera Raw, Chrome-based browsers, and Instagram and Threads. Apple calls its implementation Adaptive HDR and says it works in both HEIF and JPEG.
Where do HDR photos show as HDR?
| Shows HDR? | Notes | |
|---|---|---|
| Apple Photos, Messages, Preview | Yes | On an HDR-capable iPhone, iPad or Mac screen. |
| Yes | In the feed and full-size views. Benz reported profile grids on mobile showing SDR until you open a photo. | |
| Threads | Yes | Listed alongside Instagram in Benz's support round-up. |
| Chrome, Edge and other Chromium browsers | Yes | On an HDR display. |
| Safari | Not according to Benz's January 2025 write-up | So the web version of a post may look SDR on iPhone and iPad. |
Even on a supported app, a phone shows less or no HDR in Low Power Mode, at low brightness, or on older displays. That's the screen saving power, not a problem with the file.
How to upload without losing the HDR
This is the part that has changed most. Over 2024 and 2025 the advice moved around:
- In March 2024 Benz's first look at Instagram's HDR support found iPhone uploads lost quality and recommended Android. By December 2024 his how-to for Instagram and Threads recommended a computer browser instead.
- In an Adobe community thread, users reported in October 2025 that uploading from the iPhone app finally kept the HDR, while the iPad app and the website did not.
- Both of Benz's guides say to choose the original aspect ratio in Instagram's crop step, because cropping inside Instagram dropped the HDR in his tests. Crop in your editor first.
We haven't tested every route on every version of the apps, and Meta doesn't publish a specification. The practical approach:
- Export one HDR photo and save it to Photos on the phone you'll post from.
- Open it in Photos. If the highlights glow there, the file is right.
- Post it, keep the original ratio, and look at it in the feed on an HDR phone with Low Power Mode off.
- If it looks SDR, try the other format (JPEG instead of HEIC, or the other way round) or another device before changing your edit.
How to edit a RAW photo for HDR
With a gain map, the SDR photo is the one most people see, so edit that first and treat HDR as a bonus for the highlights.
- Get the SDR edit right. Set exposure, white balance and contrast as you normally would. In Raw Smith the HDR version is built from the finished SDR picture, so masks, the profile and every slider decide what counts as a highlight.
- Leave the bright things bright. Raw Smith's HDR rendition leaves everything below the upper midtones exactly as it is and lifts only the brightest part of the picture, smoothly, by up to four times SDR white (two stops). If you pull Highlights and Whites far down to rescue a sky, there's less left for HDR to lift. Recover what needs detail, and let the sun, its reflections and lit windows stay near the top.
- Turn on HDR Preview. On an HDR screen, the HDR button on the photo (on iPhone, Actions › HDR Preview) shows the highlights above white as you edit. It only appears on screens that can show it.
- Watch skin and white walls. Big bright areas that glow can feel harsh on a phone in a dark room. If a face or a white wall jumps out, bring it down a little with a mask.
How to export an HDR photo from Raw Smith
On iPhone and iPad
- Open the photo and tap Export.
- Set Format to JPEG or HEIC. The HDR row only appears for these two, because TIFF and PNG don't carry a gain map.
- Turn on HDR.
- For social posts, set Size to Web / Social (2048px).
- Tap Save to Photos.
Single exports on iPhone and iPad are written in Display P3, the colour space Apple's screens use, and the one photographers in that Adobe thread recommend for Instagram HDR. Raw Smith remembers the HDR setting for next time.
On a Mac
The editor's quick Export button doesn't have an HDR switch. Use batch export, even for one photo: select it in the grid, choose Export, pick HEIC (10-bit) or JPEG (8-bit), set Color Space to Display P3 and turn on HDR (Gain Map). The built-in HDR for Screens preset does this for you as a 4K HEIC. Then AirDrop or sync the file to the phone you post from.
| Format | HDR gain map | Use it for |
|---|---|---|
| JPEG | Yes | The widest support on social platforms and the web. |
| HEIC | Yes, 10-bit | Smaller files, ideal within Apple devices. |
| TIFF, PNG | No | Print and further editing, in SDR. |
The export guide lists every option.
How Raw Smith fits
Raw Smith edits camera RAW and ProRAW on iPhone, iPad and Mac and exports JPEG or HEIC with a gain map, written by Apple's own image frameworks. The HDR lift is fixed at up to two stops; there's no slider for it, and no HDR editing mode beyond the preview. What it doesn't control is how Instagram or Threads process a file after upload, so a quick test post is still worth it. Raw Smith is a free download with a free tier and a 14-day trial; Pro is a one-time purchase or a yearly plan. It's in public beta on TestFlight now.
Questions
What is a gain map?
A gain map is a small extra image stored inside a JPEG or HEIC that says how much brighter each part of the photo should be on an HDR screen. Screens that can't show HDR ignore it and show the normal photo.
What is ISO 21496-1?
It's the international standard for gain maps. Before it, Apple, Google and Adobe each stored gain maps differently, which is a large part of why HDR photos looked right in one app and flat in another.
Does Instagram support HDR photos?
Yes, Instagram and Threads can show HDR photos that carry a gain map. Which upload routes keep the HDR has changed over time and differs by device, so post a test photo and check it on an HDR phone before relying on it.
Will my HDR photo look wrong on a normal screen?
No, not with a gain map. The file's main image is an ordinary SDR photo, so screens and apps without HDR show exactly the edit you made in SDR.
Can Raw Smith export HDR?
Yes. Turn on HDR in the export sheet on iPhone and iPad, or HDR (Gain Map) in batch export on a Mac, with JPEG or HEIC. The file carries a gain map that lifts the highlights by up to two stops on HDR screens.