ZWO ASI120MM-S as an AllSky camera (Updated 12/20/17)

The ZWO ASI120MM-S camera is a good, reasonably priced guiding/planetary imaging camera.  The camera comes with a 150 degree fish eye lens that allows the camera to be used as an All Sky camera for capturing the night sky in conjunction with free programs like Fire Capture and Sharp Cap which can be downloaded right from the ZWO web site. This article will deal with that application for now and will be updated to talk about the guiding/planetary imaging later.  Therefore the title of the tab might change in the future.

The camera was attached to a sturdy Celestron tripod I had lying around and was placed on my deck between two of my telescopes.  I connected it to a Dell 2 in 1 computer that is only an 11.6 inch screen and decided to use Fire Capture since I was familiar with the program. My friend and fellow astronomer, Pete Detterline, helped with figuring out the settings in Fire Capture and with the setup.  See picture below for setup.

The computer was inside a plastic strorage container bought from the local dollar store and I cut a hole in the back to pass the wires from the camera and the AC adapter through.  A 1 TB Dell external drive was use to store the images.  The fan was a smaller version of the DDS 3000 dew elimination system which is demonstrated by Uncle Ronnie Shawley in another tab on this blog.  Don't works!  After the settings were done we started the capture program at 10:12 PM and let it run for 4 hours.  The next morning I closed down everything and downloaded the 880 images to my regular computer and made a time lapse using Cyberlink's Power Director(good program).  I then uploaded the time lapse to my YouTube channel.  I only captured one small meteor which is pictured below.

The settings can now be refined as we have a baseline to refer to the next nice, clear, calm night we set the camera up.  The link to the time lapse is below.

This is a poor man's Oculus All Sky camera.  It doesn't rival it, but it doesn't cost anywhere near as much either.  This is just another idea to use the camera for if you haven't tried it.  As I said early the guiding/imaging results will be added at a later date.  Clear skies to all readers.

Update 4/10/17

Latest version of my ZWO All Sky camera.  Added a heavy duty U.S. Pro tripod and then added a 3/8 to 1/4 inch screw adapter to attach the camera.  The adapter has  a 5/8 inch base so a fellow amateur astronomer drilled two holes in some scrap plexiglass and 1/4 inch plywood and I put that over the adapter to act as a base to allow a shield to be put on top.

Since I already have a BloomSky for daytime sky images the shield ends up being protection from bird bombers when I set up the camera during the daylight hours and I take it off at night.  Dew and frost is taken care of by the Dave's Dew System 2000(see another's a tongue in cheek presentation by Uncle Ron Shawley, but don't laugh, it really does work.  I have used variations on it for several years and have never had a problem).

The sky last night was horrible.  High cirrus clouds covered the sky and the nearly full moon really knocked down the seeing.  Below is a link to a short time lapse from last night.  The weather was too good to pass up testing the new setup, but the sky did not help.  Next good night I will try again.  Stay tuned for updates.

Link to ZWO All Sky 2nd try.

Update 4/18/17

The reason for the long version is because I thought I had all my settings ready in Sharp Cap and just pushed Start and away it went.  Next morning I discovered I had over 11,000 images for 6 hours of imaging.  I was planning on 720 images­čśÇ.  Needless to say I wondered what I did.  Well, I forgot to set the exposure length to 30 secs and instead got the default of 50ms.  Bit of a difference.  I had to do 6 short timelapses and combine them into one since my program "Cyberlink Power Director" can only handle so many at one time.  After making the long one(which came out really smooth) and shortened it up for those with little time to watch.  Hopefully will have all settings correct on  4/21/17 for the Lyrid meteor shower.

ZWO All Sky 4/18/17 Long Version

ZWO All Sky 4/18/17 Short Version and no music

Update 6/21/17

Getting better with the settings on SharpCap with the ZWO, but not quite there yet.  Still working on exposure limits.

ZWO ASI120MM-S 6/20/17

Update 6/28/17

Best one yet.  Sky was the best it's been in awhile.  Settings are close to perfect for my area.  If tonight is clear I will set up in a little different area for a somewhat different view.

Picked up a ZWO ASI224MC camera for guiding, imaging and EAA, but first decided to try it as an all sky.  The 224 has a CMOS chip with high sensitivity and so decided to use it as a comparison piece to the 120.  The price difference for the two cameras is about $50.  The link below will take you to the ASI224MC time lapse on my YouTube channel.

ZWO ASI224MC All Sky Camera

Planes, clouds, IRs, meteors and the Summer Milky Way in the beginning.

10/6/17 Update

I took a 12 hour movie of last night's sky and because of the SharpCap program frame rate it automatically condensed it down to 1:02 with title and ending.  Link is below.


  1. Very nice 12h video in just over 1 minute! What settings did you use? I have a ASI120MC-S and would like to try the same.

  2. The settings were Raw 8, Exposure was set to Auto. Under start capture I set it for 12 hours, 1 sequence and 1 sec in between although that last one is unnecessary. I do it from force of habit when I do PNGs. I'm doing one tonight although the sky is iffy. If it turns out good I'll post it. I'm using an ASI224MC-S tonight. All my time lapses are on my YouTube channel if interested.

    1. Thanks. Sky has been terrible here the last week.

  3. Great stuff. I have a ZWO ASI224MC. Struggling to get it going as an All-sky. Curious, why did you switch from FireCapture to SharpCap? Specifically, are there features in SharpCap that are advantageous for All-Sky? Thanks!

  4. Fire Capture has always been a struggle for me. Sharp Cap was easier. I'll give you hand if you want. Email me at to set it up.

  5. I too picked up a ZWO ASI120MC, have had interesting results with SharpCap, but have not given FireCapture much more than a cursory look over. Please Help! with settings. These are very sensitive pieces of equipment. I would love to have your results. If you would be so kind as to share your capture settings.. I believe SharpCap actually saves all the settings in a file in the capture folder root for each cap. I will have to take some pics during the daytime to show you what I came up with rigging wise.. I live in PRIME dark territory, backside of the Mountains from Albuquerque. It does get quite dark here, & at 7600ft Altitude. I knew I needed an AllSkyCam asap. I very much look forward to hearing from you.. Please feel free to email me at
    Thank you Friends