A field review of the Astrel AST8300M
Let me start this review with a little introduction and some background to what I have been doing in the astrophotography space.
I am Achim, 42 and I am doing astro imaging since the end of 2015, starting with a DSLR (Nikon D5300) and some planetary imaging with an ASI224MC, using different optics ranging from a 10“ f5 newtonian to a widefield 90/600 f6.6 apo.
I am mainly dependent on a mobile setup, which is why I was looking for a camera that best supports my needs. I started to do some research and read several reviews on CCD chips, camera types, how to control and sequence them. My conclusion was that doing mobile imaging with a mono CCD can be leading to a complex setup with a lot of components.
By chance I got some information on the Astrel AST8300M camera and did some research into the camera as well. It is based on the rather „outdated“ KAF8300 sensor, comes with a built in 7 position filter wheel and an onboard Linux based PC system that lets you control all camera functions and some additional AP components. Comparing the features with my needs I was quickly pulling the trigger and got myself a shiny new toy.
At this point some may argue that there are better sensors then the KAF8300, especially when it comes to noise levels. Astrel Instruments has implemented the sensor readout in Software and is able, with multisampling, to reduce overall noise levels to roughly 6-7e.
When the camera arrived it was neatly packaged. As I ordered the entire package it included WIFI dongle, touchscreen, low vaccuum pump and power supply cabling. A camera test report was also included describing readout noise and overall system noise. It promised system noise of roughly 6e.
As I bought the camera from a german Astrel retailer I had to mount the filters into the camera myself, which can be a bit tricky and should have some preparation in order not to have too much dust enter the camera body. In addition you need to fine tune filterwheel calibration as the camera accepts 27mm filters that are very close to the sensor, so vignetting might be an issue if calibration is not correct, but this is well described in the user manual. Alternatively, if you buy it directly from Astrel, they are offering a free of charge filter mounting service.
Booting up the camera and using the apps is pretty self explaining and does not pose too many problems, even for non IT people 😉
One of the pretty smart concepts of the camera is the way how they are handling subzero cooling temperatures and possible frosting. The camera is evacuated and a low vacuum condition is achieved by using a vacuum pump before you start cooling the camera. Usually the vacuum will last for weeks so this procedure is nothing you need to do often.
Lets get to using the camera in the field. As said I am depending on a mobile setup, which consists of my optics, an AZ-EQ6, an MGEN autoguider, my Astrel camera and a small tablet. As always with mobile setups you need to bring enough battery power to keep everything going. The camera itself usually consumes 2A per hour depending on how you set the temperature delta.
As soon as everything is set up you can connect to the camera either by using a WiFi or LAN connection using a VNC client. Using the external touchscreen is something I only did once. The one supplied in version A is not really that useful. The screen that comes with version B of the camera is supposed to be a lot better, although I have not tried that myself, but either using a tablet or my phone to control it more then makes up for it 😉
One of the features I really came to like with the Astrel is the DSLR like preview function, which helps finding, focusing and framing your target a lot.
As soon as this is done you can move to planning your exposure series with the help of an app. You can chose time, number, binning and order of filters you want use. Being it sequential or interleaving. You can save your exposure settings if you like. The pictures that are taken are stored on the cameras internal storage or, if you like, can be saved to an USB stick that can be externally connected.
If you like you can use the integrated autoguiding that is based on the Lin_Guider software. It is a bit tricky finding all the right settings and UI performance in the A version of the camera is not optimal. Again, version B, as it features a more powerful CPU, is remediating this issue. Once you tackled settings and user experience the overall guiding performance is very good.
If, like me, you are using an MGEN you can connect it to the Astrel and have them communicate and control dithering, which is a very nice feature.
So everything set up, configured and ready to go you can hit the „shot“ button and the camera starts exposing while the MGEN is guiding. Usually this the moment when I am starting to watch the sky and relax. You can use the monitoring app to see how the camera and exposure series is doing. You can even check the images that the camera has taken with an app, although the resolution in the A version is not good, again solved in version B.
Rating the imaging performance of the Astrel is simple, it is very good, although I do not have a direct comparison in terms of a CCD, only a DSLR. Noise is very low as promised. I have attached some pictures that have been taken with my setup.
With so many good things usually comes some sort of caveat. This is why I am going to list some things that I not fully like or I think can have some improvement:
- Steep learning curve due to very basic user manual
- Downloading large amounts of images takes a lot of time (solved with external USB or using version B of the camera)
- Internal clock is not buffered, you need to set this every time or use an external GPS dongle offered by Astrel Instruments
- The mechanical shutter makes taking flats a bit tricky. You need to watch timing (at least 5 seconds), so you better bring a dimmable flat field box or something 😉
Let me close with a brief summary and a comment on the service and support.
All in all I found what I was looking for in the Astrel AST8300M. The camera performs very well, is easy to use (once you get it), fully supports my mobile requirements, is upgradeable (they are working on KAF16200 based version) and, as not mentioned before, very lightweight. It is as close to a DSLR experience as you can get with a full astro CCD.
Last but not least I want to mention the service and support provided by Astrel Instruments. As always things can break or you might have questions. So whatever issue I ever face with the camera (had to service it once) was quickly solved. Communication was very timely, advise excellent and to the point and we have an ongoing dialog of possible things to put into the next version of the firmware 😉
I can only recommend the camera and hope that my review has helped answer some questions. I am happy to answer any addtional questions you might have via PM oder my mail.