On April 26, 2021, Apple released Catalina Security Update 2021-002 (19H1030) for macOS 10.15.7.

This security update breaks OpenCL, a framework from Apple used by Observatory for processing images. After installing this update, Observatory will display the error message “An error occurred while initializing OpenCL“ upon launching, and terminates.

The release notes for the security update do not mention OpenCL, and I’m baffled how this got through Apple’s internal QA. Every application using OpenCL directly or indirectly is affected by this, not just Observatory. I’ve immediately filed a bug report with Apple but have not yet received a response.

Big Sur 11.3 (20E232) and Mojave 10.14.6 (Security Update 2021-003, 18G9028) have not been affected by this bug. Older macOS versions didn’t receive a security update so they too have not been affected. The regression exists only in the Security Update for macOS Catalina. Before applying it, OpenCL works correctly, but after applying it, it does not anymore.

I would normally never recommend this, but until this is resolved by Apple, please do not install Catalina Security Update 2021-002.

Update 2021-05-06: Catalina Security Update Developer Beta 2021-003 fixes the issue, so I expect it to be resolved in the upcoming Catalina Security Update 2021-003.

Update 2021-05-24: Today Apple released Catalina Security Update 2021-003 (19H1217) for macOS 10.15.7. Whereas the beta fixed the OpenCL regression, this public release does not. Apple retroactively breaks functionality in macOS, doesn‘t admit it, doesn‘t respond to a detailed bug report (FB9090655) that includes sample code to demonstrate the regression, and most importantly, doesn‘t fix it. What gives?

If you haven‘t installed Catalina Security Update 2021-002 yet, then you can safely install Catalina Security Update 2021-003. It contains all of the 2021-002 changes, but doesn‘t break OpenCL. Apple excluded the fix for the 2021-002 OpenCL regression that was in beta 19H1210 from it though, so applying 2021-003 after 2021-002 still leaves you with broken OpenCL. Interestingly, this also means that macOS 10.15.7 19H1217 on one system now may not be the same as macOS 10.15.7 19H1217 on another system. What a mess.

Update 2021-06-03: If you have already installed the Catalina Security Update, you can solve the issue by restarting your Mac in macOS Recovery (press ⌘R upon restart) and choosing Install macOS. This reinstalls macOS Catalina 10.15.7 (19H15). It will not erase any data, but do make a Time Machine backup beforehand anyway. You could then install Catalina Security Update 2021-003. The OpenCL issue may be hardware specific though, as on a Late 2013 MacBook Pro Catalina Security Update 2021-003 breaks it as well.

Update 2021-08-12: Observatory is supported on macOS version 10.11 (El Capitan) all the way to the latest beta of upcoming macOS 12 (Monterey), but in the latest security updates on Catalina 10.15.7 Apple introduced a regression on some older hardware for which the only workaround is to revert these security updates, or upgrade macOS.

For example, Observatory runs fine on macOS 10.15.7 and the latest Catalina Security Update 2021-004 on a 2019 MacBook Pro and also on a Mid 2012 MacBook Air. But on a Mid 2012 and Late 2013 MacBook Pro it only runs with macOS 10.15.7 up to build 19H524, but not on any 19H1xxx build. It may be a coincidence, but these machines each have a NVIDIA GPU. The GPU shouldn’t matter, and OpenCL should at least be working on the CPU, but it doesn’t anymore since these last few security updates. The above mentioned workaround works well on these machines, and both the CPU and NVIDIA GPU are then supported.

To reiterate, the workaround on this older hardware is:

• Reboot the machine, press and hold ⌘R to get into Recovery mode;
• Choose “Install macOS”.

This returns it to the original Catalina 10.15.7 (19H15), without affecting any data or applications. Of course, do make a Time Machine backup beforehand anyway.

If you are running macOS Catalina 10.15.7 on older hardware, before purchasing Observatory make sure to try the demo. It will show you if your system is affected by this issue.

Today Acorn 7 was released. Acorn has a new interface and is now fully optimized for Apple silicon Macs. We have updated our FITS/XISF/SBIG Acorn image plugin today as well, and like Acorn 7 it now also runs natively on Apple silicon.

After installing the plugin, you can open FITS, XISF and SBIG images with Acorn as easy as a JPEG or TIFF while maintaining the dynamic range in your images. The plugin is free, but you do need Observatory and Acorn to use it. It’s a great addition to Observatory’s Quick Look and Spotlight plugins for the same image formats.

More information about the plugin and the download link can be found in the User Guide. Full release notes are here.

Observatory 1.6.1 is now available on the Mac App Store.

In this update we have fixed a regression in the Library Navigator that was causing its overzealous closing of folders.

When importing images, Observatory now automatically handles the incorrect scale in the WCS solution generated by ASIAIR PRO. Overlays and tags in Observatory will now be correct if you use this device to plate solve your images.

ESO has fixed a regression in their service to access raw observational data. As a result, access to the ESO archive using Observatory‘s Virtual Observatory has been restored. To better serve our needs in Observatory, we took this opportunity to adjust what data is returned. Results are now limited to the following instruments:

• EMMI/LaSilla: A multipurpose instrument for observations in the visible wavelengths at La Silla Observatory in Chile, retired in 2008.
• FORS1/VLT: An instrument at Paranal Observatory in Chile, retired in 2009 to make space for XSHOOTER.
• FORS2/VLT: An instrument mounted on the VLT 8.2m UT1 Antu telescope at Paranal Observatory in Chile.
• OMEGACAM/VST: A camera for the VLT Survey Telescope, a 2.6m telescope designed specifically for wide-field imaging at Paranal Observatory in Chile.
• VIMOS/VLT: A wide field imager mounted on the VLT 8.2m UT3 Melipal telescope at Paranal Observatory in Chile.
• WFI/LaSilla: The Wide Field Imager is permanently mounted on the 2.2m MPG/ESO telescope at La Silla Observatory in Chile.
• XSHOOTER/VLT: An imager mounted on the VLT 8.2m UT2 Kueyen telescope at Paranal Observatory in Chile.

A change in the HST service prevented Observatory‘s Virtual Observatory from searching HST images. This has been resolved.

Release notes.

Apple silicon has arrived, and so did Observatory 1.6! Observatory is now a macOS Universal app, which can run natively on both Apple silicon and Intel-based Mac computers.

Release notes.

Enjoy!

Observatory 1.5.3 has been released to the Mac App Store.

The Calibrate adjustment now tolerates small differences in ISO speed, pedestal, gain and exposure duration for its calibration frame validation. This solves the issue where the calibration frame selections sometimes didn‘t list the expected master calibration frames.

The adjustment also gained the new option to skip most of the validation altogether. So if some of the metadata is incorrect, or you want to calibrate your image with a flat taken at a different sensor temperature, now you can without having to manually edit the metadata.

Release notes.