Tag Archives: ASCOM

QHY183M Review – Part 1

After much waiting (due to delays on Sony Sensors) I have finally received my QHY183M ColdMOS camera from QHYCCD which I collected from ModernAstronomy last weekend, so I apologise for the really bad weather we’ve had.

As you all know, for the past few years I have been using an Atik 383L+ Mono 8.3Mpx CCD Camera, so when QHY announced the QHY183C I immediately asked them if there was going to be a mono version to which they said….Yes!

So firstly you might ask why I chose the QHY183 camera?  Well the simple reason for this is that it offered me a higher pixel resolution for almost the same field of view that my Atik 383L+ offered, however there were other factors that swayed my decission:

  • Back Illuminated Sensor
  • High Quantum Efficiency (QE)
  • Optimal Cooling
  • Lightweight

So let’s first of all talk about the back illumination and what this means to astrophotography.  Typically CMOS sensors are orientated with the light receiving surface and the transistors/wiring facing the light, so when imaging it is possible to get reflections of light bouncing off the circuitry, with a back illuminated sensor, all the circuitry are on the underside of the surface that faces the light, thus elliminating the possibility of reflections bouncing off the transistors, the following image shows this in a bit more detail (Courtesty of QHYCCD):

So obviously the more light we can get to the imaging surface the better it is for our data acquisition, every photon counts right?!

The QHY183M has an extremely high Quantum Efficiency (QE) of 84% which means that more data is absorbed by the chip than my previous imaging camera which had a QE of just over 60% based on the KAF-8300 sensor from Kodak.

One of the first things I tested when I unpacked the camera was the cooling system, I wanted to know how good the cooling system was, QHY stated between 40-45C Delta, so considering the outside temperature was +5C I managed to get the camera down to -41.6C which was a delta slightly above the 45C promised by QHY, so considering I typically image at -20C this now means I can image when the outside temperature at night is even as high as +25C which typically doesn’t happen in the UK.  I also noticed that the QHY183M uses less current than my 383L+ did to get ot the same temperature, so another bonus of less power requirement.

Weight is always an astrophotographers enemy, so it was much to my delight that the QHY183M weighs a lot less than my ATIK 383L+ did, the 383L+ weighed in around 700g and the QHY183M weighs in around 450g.

Out of the box
My first impression of the camera is that it is well built, a bit more of a compact design in comparison to my previous camera, has a USB3.0 connector (even though I am still using USB 2.0) and has a port to connect a dessicant tube to if required.

Software Installation
Driver installation was relatively straight forward, if you are using a third party imaging program like Sequence Generator Pro, make sure you install the ASCOM drivers so that SGPro can then speak to the camera.  In SGPro there are options for Gain settings, according to QHY the unity gain for the 183M is 11, so I have mine set to this value in SGPro.

Image Download Speed
After completing my dark frames library, I noticed that the download speed from Camera to Observatory PC was much much faster than my Atik was, even though I am using the same USB 2.0 Hub, on the Atik it could take anywhere up to 20 seconds to download the image at 1×1 binning, obviously the QHY183M is a much bigger sensor at 20mpx, however the image download time is circa 5 seconds which reduces image acquisition time greatly for multiple exposures.

Dark Frames
My dark frame library is completed, below are four different exposure times, 90, 180, 300 and 600 seconds, each image consists of 25 frames combined using PixInsight

90 Seconds:

180 Seconds:

300 Seconds:

600 Seconds:

As you can see the darks are really good, if you stretch out the images you will see the AMP glow on the right side of the image, this will be removed in dark frame subtraction and is a common artifact on all CMOS based imagers.

I did have the occasional icing issue on my 383L+, however the QHY183M has a heated optical window, so time will tell on how often I will need to use the dessicant tube.

Conclusion so far…before imaging

Pros:

  • Excellent design.
  • Lightweight.
  • Very predictable cooling system cools to -45C below ambient.
  • Cooling system is much quieter than my previous camera
  • Less current draw versus my previous camera.
  • Easy software installation.
  • Very fast download speed of around 5 seconds per frame at 1×1 Binning.
  • Very high QE of 84%

Cons:

  • AMP glow, I am probably being a bit mean considering all CMOS based cameras are subjected to this.
  • M42 thread on the camera is not long enough for the StarlightXpress EFW, I had to place a piece of card between the camera and the Filterwheel otherwise the camera just keeps spinning round and doesn’t tighten.
  • There’s no electronic shutter like my previous camera, which means for my dark frames it has to be completely dark in the observatory

I hope this review is beneficial to you all, especially if you are considering either the 183C or the 183M.  I will post part 2 of my review when I have actually got it all focused and acquired some photons from the sky.

Atik 383L+ Cooled Mono CCD Imaging Camera

After owning the Atik 383L+ Mono CCD Camera for over three years now, I would say I am definitely qualified to write a review.  I bought my camera back in 2013 when I lived in Ireland it was during the time when I transitioned from imaging with a Cooled and Modified DSLR Camera to Mono CCD Imaging.  At the time I was considering one of two cameras, the QHY8 Mono CCD and the Atik 383L+ Mono CCD, at the time the QHY was slightly cheaper but the Cooling Delta and Readout Noise was better on the Atik despite the fact that they both used the Kodak KAF8300 chip.

When I first received my camera, I was thoroughly impressed with the build quality, the red aluminium casing gave it a really professional feel to the camera and came complete with USB Cable, 12v Cigarette Power Cable and Software Media, all packaged really well, and when taking the camera out of the box, you could tell that Atik had put a lot of effort and consideration into their build quality and finish of the camera.  So far so good!

People quite often ask me how big the camera is, it just so happens that at the time I got my camera, I took a picture of the camera next to a AAA battery, just for comparison you can see that it is a fairly compact camera and at around 700g wasn’t too heavy either.

Because I couldn’t wait until my filterwheel had arrived, I wanted to test the camera functionality, so I installed all of the software onto my desktop PC and plugged the camera in.  At the time I got the camera, I was using Nebulosity to perform my image acquisition, so the first thing to do was build my dark frames at my desired temperature of -20C.  The dark frames showed very little in the way of noise which I was extremely happy with.  The installation of Drivers and  ASCOM Platform drivers all went perfectly without any problems, and Nebulosity worked well using the ASCOM Camera platform driver.

Once my filterwheel had arrived from StarlightXpress it was time to get the camera aquainted with the telescope, and at the time I was using an Astro-Tech 8 Inch Ritchey Chretien telescope on my already 3 Year Old NEQ6-Pro mount. Mating the camera to the filterwheel was relatively easy, I placed a thin cork shim onto the male thread of the filterwheel and screwed the camera on and adjusted the rotation of the filterwheel adapter to make sure the camera was at the right angle, I used the rubber shim to stop the metal to metal binding which makes it difficult to remove later, adding in the cork shim still allows it to be tightened up.

Since I had built my dark frame library, it was time to build my flat frames library, for this I used an EL Panel, one of the things I noticed was that a short exposure time of <1.0 seconds left a dark area to the lower right of the frame, after speaking with Atik they confirmed it was just the mechanical shutter, so I had to reduce the light on the EL Panel in order to increase the exposure time to get around this, other than that my flat frame library was built.

My first light for the camera was going to come from NGC7635 – Bubble Nebula in Narrowband, and whilst I must admit my imaging has come a long way since I took this picture, it is what it is and I was very happy with the results of sensitivity the camera delivered especially as this image is only 3x1800S frames for HA, OIII and SII.  Since I have had the camera, I have produced a substantial number of images to date and continue to do so using my Atik 383L+ Mono CCD Camera.

So how does Atik fair with me as a company, well it just so happens that I had to send my camera away for service due to excessive moisture causing Ice Crystals during cooling, I filed a support ticket with them and within a few days I got my camera back completely moisture free, I do not blame the camera here for the moisture, but more the fact that when I had my observatory located 15 miles away, I used to forget to switch the camera power off which would push a lot of moisture through the camera.  But the service from Atik was simply awesome.

Here’s a picture of the camera still used today attached to my F4 Quattro, I use Sequence Generator Pro for all my target acquisitions today but still using the ASCOM Camera Driver which is extremely stable

Just to recap why I am happy with the camera:

  • Build Quality
  • Size and Weight
  • Software Deployment
  • Sensitivity
  • Quietness of the camera

What could have been better?

  • Power cable – This could have been a stretchable power cable as I did run into a problem recently where the cable became snagged and it ripped the wire out of the jack plug that plugs into the camera, fortunately it didn’t damage the plug in port of the camera
  • Heated chip chamber, most cameras seem to have this now
  • Different colour options – I would have loved the camera in Blue or Green

You can see many of the images I have taken with this camera in my CCD Image Gallery Section here