| categories:Astrophotography

M33 - A very faint Triangulum Galaxy
Agenda

I’m agonizing over a telescope purchase at the moment, so in the mean time, I’m working on automating my setup and using a telephoto lens. I dabbled in astrophotography some last year, but the bitter winter cold kept me from using my mount much.

So this time around, I’m trying it with Ekos and a raspberry pi. The RPi sits outside with the scope and runs the indi server, while I sit inside toasty and warm running the client. At least…in theory. I spent half the night battling the system.

Few problems:

  • Indi downloads the RAW file and does a conversion to FITS locally on the RPi, which is tremendously slow (1-2 minutes for a 1s exposure). There is an option to send the native RAW and convert to FITS client-side, but I couldn’t get it to work (seg faults)
  • I quit using the indi server and am instead “sharing” the USB ports over my network, which tricks Ekos into thinking the camera/mount is local to the machine
  • Ekos doesn’t seem to like bulb mode on my canon; it locks up the mirror and never comes back. In manual mode, exposures cut off at 30s and Indi gets confused, corrupting the file.
  • So I ended up aligning/plate solving in Ekos, and capturing in Nebulosity. It worked, but clunky work-flow
  • Couldn’t get focus to work…in autofocus mode the canon refuses to open the mirror. So I used manual focus and tried to focus by viewfinder as best as possible.

I wasted most of the night fiddling with software, and by time I started imaging a fog was rolling in. Took three hours of exposures: one hour was worthless and another was dodgy at best.

  • North country New York (Adirondack region)
  • Canon 7D + 400mm Canon f/5.6 telephoto
  • 53x60s exposures at 800 ISO @ f/5.6
  • 43x60s exposures at 1600 ISO @ f/5.6 (much of these had a thin fog covering the image, and I threw away another hour’s worth of exposures after that)
  • 10x60s darks at 800 and 1600 ISO
  • Nebulosity for normalization, demosaic, align, stack
  • Pixinsight for attempting to salvage the super noisy, low-signal images. Essentially followed this tutorial

Basically everything that could go wrong…did. Poor polar alignment leading to bad tracking, bad focus, terrible DSLR noise, questionable goto syncing, fog. Oh well…at least I worked some kinks out and got to practice pixinsight :)

My janky setup:

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