This article covers tests on AstroDMx Capture using some advanced functionality, but it also covers the testing of Two SVBONY cameras. The first that we shall report on is the SV705C OSC CMOS camera; a prototype of which Nicola has implemented in AstroDMx Capture and support for which will be in the next release of the software. The second is the SV405CC cooled camera that we have been exploring since its implementation in AstroDMx Capture, and which has featured in a number of previous articles over the past several months.
Testing our implementation of the SV705C as an uncooled Deep Sky Imager
Testing an SV705C prototype uncooled camera fitted with an Optalong LeNhance narrowband filter, using an 80mm, f/5, Apochromatic refractor with no field-flattener. The camera has a Sony IMX585 sensor with 2.9μm square pixels and displays no significant amp glow. The sensor has a deep well depth of 38.8ke- which allows for a good dynamic range.
AstroDMx Capture was used to acquire the objects and position them, capturing 2 min FITS exposures of the Crescent nebula and the Eastern Veil nebula. Auto-guiding was with PHD2; all using an INDI server. One hour's worth of 2 minute exposures were captured of the Crescent nebula and 20 minute's worth of 2 minute exposures were captured of the Eastern Veil nebula.
Matching dark-frames were captured, but were not subsequently used in this experiment.. The data were registered and stacked in Siril and post processed in the Gimp 2.10 and Fitswork 4.
Screenshot of AstroDMx Capture capturing FITS data on the Crescent nebula
The Crescent nebula and surrounding nebulosity
Screenshot of AstroDMx Capture capturing FITS data on the Eastern Veil nebula
The Eastern veil nebula
No field flattener was used because we wished to test whether one is needed with this camera. It is concluded that future use of this camera with the same scope will benefit from the use of the field flattener, as the sensor is quite large (11.18mm x 6.32mm), affording a wide angle of view.
These tests revealed no problems with the SV705C, which proved to be quite a capable uncooled deep sky imager. There are many more tests to perform, with different scopes.
In future sessions we shall field-test with the f/5, 80mm apochromatic refractor using a field flattener and an f/5, 130mm Newtonian using a coma corrector. We shall also test the camera for Lunar and planetary imaging using a Skymax 127 Maksutov + barlows.
The total absence of amp glow puts the SV705C in a class of cameras that, due to the sensitivity, 90% QE and 38.8ke well depth of the sensor used, are suitable for use as uncooled deep sky imagers, apart from their more obvious use as planetary, solar and lunar imagers.
Another factor to be considered is the relative sizes of the sensors in the various SVBONY cameras and, with a given scope, the field of view captured.
First of all we shall consider the fields of view captured by these cameras and shall use the SV305, the first proper SVBONY astronomical camera capable of doing both planetary and long exposure imaging, as our yardstick.
With a given telescope, the SV405CC captures 14.32 times the field of view of the SV305, 7.12 times the field of view of the SV505C and 3.35 times the field of view of the SV705C.
This means that below the SV405CC, the SV705C captures a very significant field of view which is suitable for deep sky imaging as shown above.
For completeness we can record that the SV705C captures 2.13 times the field of view of the SV505C and 4.28 times the field of view of the SV305. Lastly, the SV505C captures 2.01 times the field of view of the SV305.
The SV405CC cooled camera uses a SONY IMX294 backlit CMOS sensor with a well depth of 63ke-, a quantum efficiency of 75% and a 14bit ADC.
The North American nebula with an SV405CC OSC camera
A 2-pane mosaic of the North American and Pelican nebulae was captured. Each pane is a one hour stack of 90s exposures acquired, positioned and captured by AstroDMx Capture, whilst testing advanced functionality; Using an f/5, 80mm apochromatic refractor with a field-flattener and an SV405CC OSC camera with an Optalong L-eNhance narrowband filter.
Screenshot of AstroDMC capture capturing FITS data of the North American Nebula
