AstroDMx Capture - Technical Help for macOS

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Any procedures suggested on this website should be used carefully and will be at the users risk. Performing these procedures implies acceptance that the responsibility is with the user and the author of this website will not be held
responsible for any problems arising from the use of these procedures.

The information and procedures on this page are specific to Apple Mac computers.

ZWO USB2 Cameras

The Problem

When ZWO released their range of USB2 cameras (for example, ASI120MC), they were primarily designed to be used on Microsoft Windows. By default, these cameras use a non-standard macPacket size of 1024 instead of 512, while this
works on Windows, it is a problem for other operating systems.

In order to fix this problem, ZWO released a compatibility firmware which changed the macPacket size back to 512. However, the compatibility firmware appears to introduce other problems that may render ZWO USB2 cameras unusable on

Observed Effect

During our tests, the ASI120MC with the compatible firmware shows frequent split frames and, in the default configuration, is not usable to collect astronomical data. The problem of split frames can be reduced by increasing the USB
Bandwidth slider to the maximum value.

The firmware can be changed by visiting the ZWO website and downloading the firmware flashing tool. Unfortunately, this tool is a Windows only application so, in order to flash the firmware, you will need access to a Windows
machine. The author of the website does not recommend running this tool in Wine or via a virtualisation system.

ZWO USB3 cameras are not affected by this problem and should work perfectly with AstroDMx Capture for macOS.

SVBONY SV305 and SV305PRO on macOS

The SVBONY SV305 and SV305PRO are now natively supported on macOS. The SDK is very new and, as a result, there could be problems. If any problems are observed then please contact Nicola Mackin with details.

AstroDMx Capture can still be visualised if needed. For more information please see Dr Steve Wanwright's blog post located here. (opens a new browser session).

Known Issues | All Platforms


There are some issues with the macOS build of AstroDMx Capture. If a Mac has a high resolution screen (greater than 1920 x 1080) and has display scaling active then the preview display does not render correctly. I am investigating this issue and will release a new version once I have a fix. For now, if using a Mac computer with a high resolution display, display scaling should be disabled.

All Versions: ZWO USB2 Cameras

There are various issues with the ZWO USB2 cameras running under Linux and macOS. These issues are not caused by AstroDMx Capture but are due to these cameras having an invalid max packet size. These issues do not affect ZWO USB3 cameras.

For more information about these issues, please see Technical help for Linux or Technical help for macOS page

USB2 ZWO cameras can also be problematic under Microsoft Windows if the hardware is relatively new. For more information about these issues, please see Technical help for Windows

Show Previous Versions

Hide Previous Versions

Version 0.90.2

Due to a possible issue with the QHY SDK, AstroDMx Capture occasionally crashes when changing resolution or pixel format. Although this problem was confirmed in 0.88.2, it has not been observed in 0.90.2. This issue is mentioned here just in case it still exists.

Version 0.88.2

Raspberry PI 32bit (armhf) Due to a recent update to the 32bit Raspberry Pi OS distribution (Buster), it is not currently possible to use AstroDMx Capture in hardware acceleration mode. If you are using the 32bit Raspberry PI OS then you should switch to software acceleration by clicking on Options and then making sure that hardware acceleration is disabled.

Fedora 34: On some installations of Fedora 34, AstroDMx Capture fails to start. In order to fix this, simply remove from /usr/local/AstroDMx_Capture/lib . I will make a maintenance release to fix this problem in due course.

Version 0.84.7

If a DSLR is set to anything other than Manual then changing the exposure causes a segmentation fault and so AstroDMx Capture crashes. Make sure that the DSLR is set to Manual.

Version 0.78.5: x86-64 Linux

Some ZWO cameras show multiple error messages during the connection routine. This issue will be fixed in the next release but for now, it is safe to dismiss the messages.

Version 0.78.3: x86-64 Linux

Version 0.78.3 requires a CPU with the AVX instruction set. All CPUs manufactured from 2009 should have this support. If you have a CPU manufactured before 2006 then you should not upgrade to 0.78.3.

Version 0.68.1: Ubuntu 20.04 Problems

Problem 1: Ubuntu 20.04 introduces an incompatibility with the version of distributed with version 0.68.1. If AstroDMx Capture does not start on Ubuntu 20.04 then remove which
is located in /usr/local/AstroDMx_Capture/lib

Problem 2: New builds of Ubuntu 20.04 cause AstroDMx Capture to take about 20 seconds to start. Systems upgraded from previous versions of Ubuntu are not affected.

Version 0.66.x: Raspberry PI QHY Cameras

Due to an issue in the QHY SDK, long exposures sometimes take longer than expected. Depending upon your timeout settings, the connection monitor might reset the camera. The timeouts can be changed or the connection monitor can be
disabled from the options drop-down menu.

Versions 0.50.x and below

If multiple camera controls are changed during a long exposure then the last control will take effect, all others will be cancelled. For example, if the user changes the exposure to one minute and then immediately changes the gain,
then the exposure control will be cancelled. To avoid this issue, change one control and wait for the exposure to complete.