SX IO is a native Mac capture app with support for almost all SX cameras and filter wheels. You can get the latest version from here.

Screen Shot 2015-09-22 at 11.03.31

  • Support for almost all SX cameras and filter wheels
  • Integration with PHD2 for dithering
  • Integration with local installations for plate solving
  • Ability to make QuickTime movies from image sequences
  • AppleScript support allowing for automation via Script Editor, Automator, osascript, etc

SX IO 1.0.8

The latest version of SX IO is now 1.0.8. This is mainly a bug-fix release but there are a couple of small new features.

  • Fixed M25C decoding.
    • There was a bug in the reconstruction code for the M25C  which meant un-binned images had a slight residual matrix pattern. This release fixes that bug and adds a tool to fix un-binned full frame images from previous releases.
  • Support for Maxi filter wheel with up to 11 filter slots
    • I haven’t been able to test this on an actual device so if you have one and notice a problem please let me know.
  • Fixed crash when showing equalised RGB images
  • View menu and capture settings are now remembered when you quit the app
  • You can now set your location by dragging a pin on a map view in Preferences…
  • Fixed a progressive slowdown in continuous capture mode
  • Fixed various bugs relating to selection behaviour
  • Added cancel capture AppleScript command
  • Raised exposure count limit to 10000

As always, bug reports and feature requests are welcome. You can use the Send Feedback menu item in the app or the Contact form on the right.


SX IO supports the locally installed tools to plate solve your images.

There’s currently no Mac installer for these tools that I’m aware of but they’re simple enough to install from the command line using homebrew. To do this you’ll have to use the Terminal app which you’ll find in /Applications/Utilities, a user account with administrator privileges and an internet connection.

You can simply copy and paste each one of the lines below into the Terminal window and press return after each one. Let each one run to completion before entering the next. Some will require that you enter your admin password.

Depending on the speed of your computer and internet connection each command should run fairly quickly. The last one which installs itself may take a bit longer.

The first time you run any of these commands you may see the following alert.


Press Install and allow it to complete. This will install the developer tools required to build and its dependencies.

ruby -e "$(curl -fsSL"
brew install Caskroom/cask/xquartz
sudo easy_install pip
sudo pip install pyfits
brew tap homebrew/science
brew install astrometry-net

Now that the tools are installed you need to get some indexes for them to work with. The wide-field indexes are usually sufficient and only take up about 340MB of disk space as opposed to the full resolution ones which occupy 10GB.

To install the wide-field indexes type in the following commands. This creates a folder called in your Documents folder and downloads the index files to there.

mkdir -p ~/Documents/
cd ~/Documents/
curl -O[107-119].fits

Once they’re downloaded you can point SX IO to them using the file chooser in the Preferences… window.

That’s it, you should now be able to use the Tools-> Plate Solve command to solve your images.