Wednesday, 27 February 2019

Deep Sky results from DSLR tethering in AstroDMx Capture for Linux

Gaynor Thomas has kindly loaned us a Canon EOS 1000D DSLR with which to implement Canon DSLR tethering in AstroDMx Capture for Linux.
The Canon EOS 1000D DSLR fitted with a 2" nose-piece and a light pollution filter was placed at the Newtonian focus of an f/5, 130mm Newtonian and tethered to a Fedora Linux laptop. The rig was mounted on a Celestron AVX, EQ GOTO mount. 70 x 30s exposures (ISO 800) of M42 were captured automatically by Nicola's AstroDMx Capture For Linux along with 20 matching dark-frames. The best 66 frames were registered and stacked in Deep Sky Stacker running in Wine and the final image was post-processed in the Gimp 2.10, Neat Image and FastStone running in Wine.

The tethered camera at the Newtonian focus

Screenshot of AstroDMx Capture for Linux capturing data from the tethered camera

The Orion nebulae showing M42/43 and the Running Man nebula

Full size

The same data processed as a monochrome image in Darktable, to reveal more nebulosity

Full size

There is still a way to go, but Nicola is making progress in the implementation of USB DSLR tethering in AstroDMx Capture for Linux

Saturday, 16 February 2019

More tethered DSLR testing with AstroDMx Capture for Linux with stacking in AstroCrop for Linux

We again tested the DSLR USB tethering function that Nicola has put into AstroDMx Capture for Linux (pre release). The ability to zoom a captured image makes focusing a dream. 50 images of the Moon were automatically captured with an f/5, 130mm Newtonian and a Nikon D5100 mounted on an AZ GOTO mount. The images were then precisely cropped and stacked in our stacking prototype of AstroCrop for Linux. The stacked image was wavelet processed in Registax 5.1 running in Wine and post processed in the Gimp 2.10

 Screenshot of AstroDMx Capture for Linux
with the display zoomed to facilitate focusing

Stacked, processed image of the Moon

Screenshot of a 30s exposure of the Orion Nebula being captured by a tethered Nikon D5100 DSLR camera and AstroDMx Capture for Linux

Not all camera manufacturers have properly implemented tethered capturing in all of their models. Moreover, many of them have neglected bulb capture. Nevertheless, Nicola is implementing the functions that have been made available by the manufacturers. A version with tethered capturing capabilities will be released when it is stable

Sunday, 10 February 2019

Tethered DSLR image capture in AstroDMx Capture for Linux

Nicola is working on the next phase of the AstroDMx Capture for Linux project, that is, implementing DSLR control and image capture with USB tethered cameras.
So far, Nikon cameras are being implemented, but Canon and maybe others will follow shortly. All of the functions have yet to be implemented but at twilight this evening, we had first light as a demonstrator that things are working.

First light

The tethered camera can be seen attached to the scope, and a captured image displayed in AstroDMx Capture for Linux on the screen.

Screenshot of AstroDMx Capture for Linux and a Nikon DSLR image

When everything is working correctly for Nikon and Canon DSLRs, the program will again be compiled for the ARM processor and the Raspberry Pi.