Saturday, 13 September 2014

ZWO ASI120MC Planetary Camera - A quick review

I've been looking around for an affordable telescope camera that can do some basic Deep Sky imaging,  as well as the usual lunar and planetary work.

I have a Pentax DSLR,  but it maxes out at 30 second time exposure,  and the picture gets very "noisy"  if you push it past about ISO 1600, so it is only capable of capturing the very brightest DSOs.  Added  to that,  it doesn't have any video or "live view"  mode,  and the back screen can only be used for reviewing shots after they are taken,  it doesn't work as a viewfinder.  (Have you ever tried to compose a night-sky view and check focus on a star through the optical viewfinder of a DSLR body which is mounted on your telescope? It ain't easy!)

I also have a Future Optics 3 Mp TVV3000 digital telescope camera: This works fine for its intended use (terrestrial and planetary imaging),  but it only has "typical"  webcam sensitivity,  and has no long exposure capability,  so DSO work is pretty much ruled out.

The ZWO range of CMOS telescope cameras has been getting some pretty good reviews recently,  and the price seems almost too good to be true. These cameras use the cheaper CMOS "webcam" sensor technology as seen in planetary cameras,  rather than the more expensive CCD sensors usually seen on Deep Sky cameras,  which explains their lower price,  but they have the sensitivity and long time exposure capability to also be used for basic deep sky work.

I opted for the 1.2 Mp colour ASI120MC camera -  key specs for this camera are:

Sensor: 1/3" CMOS AR0130CS
Resolution: 1.2Mega Pixels 1280x960
Pixel Size: 3.75µm
Exposure Rage: 64µs-1000s (That's 1,000 seconds,  or more than ten minutes - more than adequate for my humble telescopes!)

A really nice feature is the solid anodised aluminium body (red for this model -  MUCH nicer than the standard plastic body you normally get with a low price camera!), which is 2" outside diameter (to fit straight into a 2" focuser),  with a standard M42 T2 thread on the inside to screw onto common camera adapters.  And of course,  it also has a 1 1/2" eyepiece adapter -  you shouldn't have any trouble fitting this to your optical train!

Something which really sets it apart from the competition is that it also ships with a 150° super-wide-angle lens for doing "all-sky"  imaging,  without using your telescope -  brilliant for capturing meteors or satellite fly-overs! The wide-angle lens screws into an adapter which fits into the T2 thread,  so I imagine you could fit other CCTV camera lenses if you want. The back of the camera body has a standard camera thread,  so you can mount the camera straight onto a tripod for use with a lens fitted -  a nice touch!

And one more thing (as Steve Jobs used to say)  - it also has a built-in auto-guider port,  so it can also be used for auto-guiding as well as imaging.

The asking price is US$279 (+ US$20 for express delivery) - I don't know of any other camera that comes close in performance and features for that sort of money.  I ordered it direct from  the Chinese factory last Saturday, and received it in Brisbane Australia yesterday (Friday) - 6 days from order to delivery, a really excellent delivery service!

I unpacked it, plugged it in, and turned it on - and it worked perfectly, straight out of the box! (The wide angle lens comes pre-installed,  so the first thing I saw was myself,  and the ceiling of the room where I was sitting.) I have tried it on two computers - an older Dell Windows 7 laptop,  and a new Toshiba Encore 8" Windows 8 tablet -  and it works perfectly with both.

The supplied software is excellent - the Windows drivers installed without incident,  and the recommended FireCapture imaging software and AutoStakkert stacking software are both powerful and easy to use.  (I've used RegiStax previously,  but AutoStakkert seems to me to be much simpler and more intuitive,  and gives excellent results with this camera.) The camera seems to be recognised as a standard Windows device,  so it will probably work with any other software of your choice,  but I'll stick with FireCapture and AutoStakkert for now.

After a bit of playing indoors to check out the functionality and the software, I took it outside, and was immediately getting better video and images than I have managed to date with my other equipment.

For my first night-time capture,  I set up the camera with the wide angle lens looking straight up from a tripod,  and got some all-day videos.  While I still have to learn a bit about optimal exposure settings,  I'm pretty pleased with the results I was getting within 5 minutes of taking it outside!

I then attached it to my 90 mm Mak,  and grabbed a few quick star shots - nothing to compare with the Hubble Space Telescope,  but still very gratifying to me,  and much better than anything I've managed before.

It's not often that things work so easily, and so well. This camera is a superb product, and unbelievable value for the selling price. It really does do everything that is claimed.

I'm going to have a lot of fun with this! (Stay tuned for more images and videos.)