Hasselblad released Phocus 4.2.3 for Mac overnight. The read-me is dated October 14, the installer went up on Hasselblad's CDN early on October 15, and my release monitor picked it up from the downloads API just after midnight Eastern.
- Direct download: Phocus_4.2.3_Mac.dmg (748 MB)
- Release notes: Phocus-Mac-read-me.pdf
The changelog is one line long. "Fix crash during adaptive chromatic aberration correction." That is the crash I wrote up in Four Clicks to a Crash on October 10. I retested it this morning: Phocus 4.2.2 still crashes on the first try, and 4.2.3 ran Adaptive CA seven times without a crash.
Key finding: Phocus 4.2.3 for Mac (dated October 14, 2026) has a one-line changelog: a fix for the crash when Chromatic Aberration is set to Adaptive. In my retest, 4.2.2 crashed first time; 4.2.3 ran seven Adaptive CA calculations on six X2D II files without crashing. If you use Adaptive CA, update.
What Phocus 4.2.3 changes, according to Hasselblad
The read-me that ships with 4.2.3 is the 4.2.2 read-me with a new heading, a new date (October 14 instead of August 20), and one block added at the top of the changelog. It went from 1,546 words to 1,554. Here is the block, verbatim:
Fix crash during adaptive chromatic aberration correction
That is all of it. Both 4.2.1 and 4.2.2 closed their changelogs with a catch-all "fix other known issues" line. For once the read-me names a specific bug, and it is the one from my October post.
The "New features in 4.2" section above the changelog is untouched, so the PDF still opens with June's feature list. 4.2.3 arrives 55 days after 4.2.2. I track every 4.x read-me against what testing shows on the release notes ledger.
One line is still a claim about what changed, so I compared the two application bundles file by file. The claim holds, and the details are further down.
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Phocus 4.2.3 fixes the Adaptive CA crash: the retest
On the evidence I have, it does. I ran the test on a second Mac, a Mac mini (M4, macOS 27.0), with 4.2.2 first as the control.
Phocus 4.2.2. I opened an X2D II 100C .3FR, waited for the preview to render, expanded Lens Corrections and set Chromatic Aberration to Adaptive. Phocus quit about two seconds later.
Phocus 4.2.3. Same steps, seven times, on six different X2D II files, across three launches of the app. No crash.
What the bundle diff shows: one code change
I compared the 4.2.3 application bundle against 4.2.2 before installing it. Of 1,275 files, 1,133 are identical and 142 changed. Nothing was added or removed.
The code change is a single topic. In the main Phocus binary, every changed instruction sits in the viewer's Adaptive CA callback or in the code that runs when a viewer is torn down. None of Hasselblad's eleven frameworks changed any code; the differences there are build identifiers and version strings. No string, method or class was added or removed anywhere. The one-line changelog is accurate, which is not a sentence I get to write about Phocus very often.
The rest of the changed files are resources and build churn. All 85 encrypted lens-correction and colour files differ at the byte level, in the pattern you would expect from re-encrypting the same data, though I can't see whether anything underneath changed. Seventeen interface layout files and the app icon changed in small ways I haven't decoded. The signing identity, entitlements and notarization are the same as 4.2.2.
For engineers: in 4.2.2, the block posted to the main queue held references to a flag and to the viewer, and those references pointed into a copy that lived on a worker thread's stack. That is the mechanism the October post described. In 4.2.3 the posted block carries its own copy of the flag and a weak reference to the viewer, which it checks for nil before use, and the viewer now clears its Adaptive CA callback when it is deallocated. That matches the fix the October post described: copy the flag, hold a proper reference to the viewer.
Have you seen the guide? I've published Essential Phocus 4.x for Mac - 85 topics across 8 sections and 251 pages covering everything from HNCS color science to HDR workflows. It's the reference manual Hasselblad hasn't updated since 3.8. It's $49, and updates are included.
Should you update to Phocus 4.2.3?
If you use Adaptive CA, yes, today. 4.2.2 crashes when you switch it on and 4.2.3 does not. If you don't use it, 4.2.3 is 4.2.2 plus one fix, so what I said in the 4.2.2 post carries over. On 4.2.2, the update dialog offers it the next time you launch Phocus.
Going back works the same way as always. Download the older installer and install it over the new version. Every 4.x build is still on Hasselblad's CDN, and the version history has the links.