Saturday, 14 September 2019

M13 in a bright, moonlit sky with a Bresser Messier AR 102xs f/4.5 refractor and an SVBONY SV305 camera

A motor-focuser adapted Bresser Messier AR 102xs f/4.5 refractor (see previous blog post) was placed on an HEQ5 GOTO mount, and an SV305 camera was placed at the prime focus.
30 x 15s exposures were captured of M13 with matching dark-frames. The best 27 frames were dark-frame corrected and stacked in Autostakkert!3. The resulting image was post-processed in the Gimp 2.10.

Click on the image to get closer views.

M13 with an SV305

Notwithstanding the 99.7% Moon in the sky, the SV305 performed well, as did the motor focuser.

Wednesday, 11 September 2019

Motor focusing the Bresser Messier AR 102xs f/4.5 refractor

The Bresser Messier AR 102xs f/4.5 refractor is a fast, ED, short tube refractor with a novel zero image shift hex-focus system with a helical gear rack, reducing backlash in the focuser. The focusing system is very good for visual observing but falls short for imaging. Whilst turning the focusing knobs the image rapidly goes through focus and it takes a long time to achieve a satisfactory focus. There is an optional slow motion focuser that can be retrofitted. However, I was unable to get it to work properly and after many attempts, plus speaking to the distributor, it was decided to return the slow motion system. I do not know what the problem was, maybe with my scope or with the focuser. I decided that if this scope is to be used for imaging, the purpose for which it was intended, I would have to attempt to fit a motor focuser, although it was not immediately obvious how this could be done, as the underside of the focuser is by no means standard.
I decided to use a Skywatcher auto-focuser and to modify the bracket with which it attaches to the scope. The modification involved drilling a hole in the bracket large enough to accommodate the large, black locking knob on the base of the scope and to use a large washer to distribute the force. This worked fine and the two photographs below show the motor focuser attached to the scope. Two strips of double-sided tape were used either side of the black knob between the bracket and the scope before the black knob was tightened down, to help resist turning of the assembly during focusing.
With the motor focuser in place, there is no need to lock the focuser once focus is achieved as this is done by the friction of the motor.

The system works, and now it remains to be seen how easily focus can be achieved with a camera attached. The advantage of this system is that the modification is to the motor focuser bracket and not to the scope. The first tests will probably be done with the SVBONY SV305 camera.

Sunday, 8 September 2019

First deep-sky with the SVBONY SV305 camera

Although there was a 63% waxing Moon in the sky, the Moon was quite low during this lunation. A globular cluster was considered to be the best class of deep-sky objects on which to make the test.
Until Nicola is given the Linux and macOS SDKs with which to implement the SV305 in Linux and macOS, we have used SharpCap in a fresh build of Windows 10 with which to capture data.
An ED f/5.5, 80mm refractor was mounted on a Celestron AVX GOTO mount and the SV305 camera was placed at the prime focus.
80 x 20.3s exposures of the globular cluster M2 were captured in RAW12 as 16 bit Tiffs along with 30 matching dark-frames at maximum resolution of 1920 x 1080.
The best 72 frames were dark-frame corrected and stacked in Autostakkert!3 to debayer the Tiffs, giving a total exposure time of just 24.36 minutes. The final image was back-cropped to 1920 x 1080 and post processed in the Gimp 2.10.

Click on the image to get a closer view


Notwithstanding the bright sky due to moon sky-glow, the SV305 performed well and produced a pleasing image of M2, demonstrating that this camera has the capability of capturing deep sky images.

Saturday, 7 September 2019

First tests on the SVBONY SV305 astronomy camera

SV305 a new Astronomy camera

We were supplied with a SVBONY SV305 camera by the company and have started testing this astronomy camera, prior to implementing it in AstroDMx Capture for Linux and macOS
This is a home grown, full-fledged, one shot colour astronomy camera from SVBONY. It uses the back-illuminated Sony IMX290 6.5mm (diagonal) CMOS sensor with 2.9┬Ám square pixels. Like a number of astronomy cameras available at the moment, it features 128MB of DDR ll RAM as an image buffer. It has a USB2.0 computer interface. It is a 2Mp camera giving a maximum resolution of 1920 x 1080. It supports arbitraty size ROI and has a 12bit ADC. The camera outputs 8 bit and 12 bit RAW data. The exposure range is from 1 ms to a respectable 30 minutes.

Unboxing the SV305

The SV305 arrived in a sturdy box containing the camera, a 1.25" , filter-threaded adapter with a dust cap, a C/CS adapter that allows the attachment of a C/CS lens if required, a 1.5m USB 2.0 lead with a short flyout lead with a USB connector for extra power if required.

The camera housing

The SV305 is housed in a well built, aluminium case of familiar design, reminiscent of earlier SVBONY electronic eyepiece cameras distinguishing this camera at a glance, from similar cameras from other manufacturers. The camera is uncooled, but the metal case should facilitate excess heat dissipation.
The IMX290 CMOS protector is protected behind an optical glass window. The overall look and feel is of a well built, sturdy camera.

First Light

The first tests were made with a freshly built Windows 10 laptop running SharpCap capture software. Linux and macOS implementation will be completed for AstroDMx Capture as soon as we are provided with SDKs.
The SV305 was placed at the Cassegrain focus of a Skymax 127 Maksutov telescope mounted on a Celestron AVX GOTO mount.
Four overlapping regions of the 46.7% waxing, crescent Moon were imaged at maximum resolution 1920 x 1080. Four, 5000-frame SER files were captured. The best 50% of the frames in the SER files were stacked in Autostakkert! 3. The resulting images were wavelet processed in Registax 5.1, cropped back to exactly 1920 x 1080 in the Gimp 2.10, stitched together into a 4-pane mosaic in Microsoft ICE and post processed in the Gimp 2.10.

4-Pane Mosaic lunar image

Full size

First impressions of the SVBONY SV305 are very favourable. The camera behaved perfectly during the imaging session and was a pleasure to use. Further testing will involve planetary imaging, and, when the Moon is out of the way, Deep-Sky Imaging. The results will be posted here when they are obtained and news of implementation in Linux and macOS will be posted as soon as it is done.

Sunday, 25 August 2019

Saturn with a DFK 21AU04.AS camera, Skymax 127 and some Python code

I have been writing Python code using OpenCV3 to capture images and AVIs from a DFK 21AU04.AS camera.
Using a Skymax 127 and a 2.5 x Barlow, an AVI of Saturn was captured using a Huffman lossless compression fourcc code. there is currently a problem using the uncompressed codec, which used to work but at the moment does not. This is not much of a problem as the compression used is lossless. The AVI produced was imported into VirtualDub running in Wine and saved as an uncompressed AVI which could then be read by Autostakkert!

Screenshot of the program running on an Ubuntu laptop, capturing an AVI of Saturn

Saturn, wavelet processed in Registax 5.1 and post processed in the Gimp 2.10

Thursday, 1 August 2019

Controlling a tethered Canon 4000D DSLR with a Raspberry Pi4B and AstroDMx Capture for the Raspberry Pi

A Raspberry Pi4B was mounted in an open, acrylic case fitted with a fan. The fan was mounted upside down so that it blows air down onto the SOC, RAM and network chips which were all fitted with aluminium heat sinks. The heat sink for the SOC was a CPU heatsink and the heatsink for the 4GB RAM chip was a cut down CPU heat sink, cut to fit the RAM chip exactly. The reported temperatures of the CPU and GPU were only 29 degrees Celsius during the capturing session.

A 120 GB SSD was fitted inside a USB 3.0 caddy and was connected to a USB3.0 port of the Raspberry Pi4B. The SSD case was attached to the Raspberry Pi case with cable ties. Small rubberised plastic feet were stuck to the base of the Pi and the SSD caddy to protect any surface the device is placed on.

The Raspberry Pi

The System was set up to boot and run from the SSD and the SSD was used to store the image results as Tiff files.
The Raspberry Pi was connected via HDMI to a 10.1 inch HD monitor and was controlled by a Raspberry Pi Mouse and keyboard.

The imaging setup

A Canon EOS 4000D DSLR camera was placed at the Newtonian focus of a Skywatcher Explorer 130 PDS 130mm, f/5 Newtonian and tethered to the Raspberry Pi.
AstroDMx Capture for the Raspberry Pi was used to capture 25 x 90s exposures at ISO 3200 of the Omega (Swan) nebula with 5 matching dark-frames.
The data were transferred quickly by USB3.0 to a MacBook Air for processing.
Deep Sky Stacker running in Wine was used to stack the best 24 images. The resulting image was post processed in The Gimp 2.10, Neat Image and FastStone; the latter two running in Wine.

The Omega nebula

This was a quick demonstrator of the system under conditions of poor transparency and without a light-pollution filter. Nevertheless, it can be seen that the Raspberry Pi4B is very suitable for astronomical imaging.
Nicola has built the necessary tool chains and cross compiler so that the software can be run on the Pi. The software will be released about the same time as the next version of AstroDMx For Linux, with DSLR support as well as a version for macOS.

Wednesday, 10 July 2019

Astronomy Linux with AstroDMx Capture

There is a distribution of Linux called 'Astronomy Linux'. It is based on Ubuntu and comes with a number of astronomical packages pre-installed. Our software, AstroDMx Capture for Linux is one of the pre-installed programs. Running AstroDMx Capture in Astronomy Linux still allows you to check for newer versions of AstroDMx Capture and download/install a newer version if required. At the time of writing, the latest version is pre-installed.
Being based on Ubuntu, Gnome 3 is the desktop environment provided with the Astronomy Linux.

Screenshot of Astronomy Linux showing some of the pre-installed software, including AstroDMx Capture for Linux.

Both the standard and debug versions of AstroDMx Capture can be seen on the first page.

Astronomy Linux is being actively maintained and may be the way to move to Linux from another OS and have many astronomy programs immediately available to use.

Monday, 8 July 2019

M27 with a tethered Canon 4000D and AstroDMx Capture for Linux

Nicola has been working on three versions of AstroDMx Capture: the Linux, macOS and Raspberry Pi (Pi versions 3B and 4B). This has involved building new tool-chains to enable the efficient compiling of the software. A test was performed on the night of July 5-6th.

A Canon 400D DSLR (with a 14 bit ADC) was directly mounted to an f/5, 150mm Newtonian and USB-tethered to a Fedora Linux laptop running the latest development version of Nicola's AstroDMx Capture for Linux. The software completely controls the functions of the DSLR. 30 x 60s exposures were captured of M27 along with 5 matching dark-frames.

The best 27 images were stacked in Deep Sky Stacker and the resulting image was post processed in The Gimp 2.10 and Affinity Photo and FastStone.

IR photograph of Nicola Gathering data on M27 with AstroDMx Capture for Linux and a Fedora laptop.

The Dumbbell Nebula, M27

The software is approaching a new release with more features, particularly DSLR support and hardware acceleration.

Tuesday, 14 May 2019

AstroDMx Capture for MacOS, bad seeing and large frame-counts

When the seeing is bad the atmosphere bubbles and the image distorts, coming in and out of focus. However, if you look carefully, there are brief moments of clarity. If a very large number of frames are captured and all but a small percentage of the best quality frames are discarded, it is possible that when the remaining frames are stacked, a worthwhile image will be obtained.
A QHY 5L-ll-M camera fitted with a x2.5 Barlow, was placed at the Cassegrain focus of a Skymax 127 Maksutov, which was mounted on a Celestron AVX EQ, GOTO mount.
AstroDMx Capture for MacOS was used to capture a 20,000 frame SER file of Crater Clavius (70.7% waxing Moon), with a region of interest of 800 x 600; and the following night, a 30,000 frame SER file of Clavius (80.7% waxing Moon) was captured.
The best 5% of frames of the 20,000 frame SER file were stacked in Autostakkert!3 running in Wine, wavelet processed in Registax 5.1 also running in Wine and post processed in the Gimp 2.10. The best 4% of the 30,000 frame SER file were similarly processed.

Screenshot of AstroDMx Capture for MacOS capturing the 20,000 frame SER file of Clavius

Crater Clavius, stack of the best 1000 of 20,000 frames

The following night. Stack of the best 1200 frames of 30,000 frames

Screenshot of AstroDMx Capture for MacOS capturing the 30,000 frame SER file of Clavius

       6 pane mosaic of the terminator of the 89% waxing Moon
Best 10% of 10,000 frame SER files

Monday, 13 May 2019

AstroDMx Capture for MacOS and a 3-pane High resolution lunar mosaic

A QHY 5L-ll-M camera was fitted in a x2.5 Barlow and placed at the Cassegrain focus of a Skymax 127 Maksutov. AstroDMx Capture for MacOS was used to capture three 10,000-frame SER files of overlaping regions of the 59.7% waxing Moon.

Screenshots of AstroDMx Capture for MacOS

Screenshot of AstroDMx Capture for MacOS maximised, and showing the reticle

3-pane mosaic of Montes Alpes, Vallis Alpes, Montes Caucasus, Aristoteles, Eudoxus, Cassini, Aristillus, Autolycus, Archimedes, Montes Apenninus.

Ptolomaeus, Alphonsus & Arzachel.