How to automate capturing a total Lunar eclipse? [Solar System] Acquisition techniques · Tomás Andonie · ... · 2 · 78 · 1

Good afternoon,

Tomorrow, Friday the 14th, at dawn, there will be a total lunar eclipse, and of course I'm going to photograph it. I'm planning to do a timelapse, so I need to photograph the eclipse from start to finish. The problem is that I have to get up at 6 a.m. that same day to go to the university, and skipping is not an option.

So the idea of spending all night photographing the eclipse awake, doesn't appeal to me. (I will do this only as a last resort).

That's why I want to try to automate the session of that night, as much as possible. My gear basically consists of:
• Nikon D3300
• Nikkor 55-300mm
• SkyWatcher StarAdventurer 2i
• AsiAir Mini

So, tracking the Moon during the eclipse isn't a big deal, as it's easy to do with the Startracker mount and the AsiAir. But I'm struggling with how to configure the camera. Since it's a lunar eclipse, the light variation changes drastically during the eclipse. So, a single configuration won't work for me; I have to keep changing it.

The only thing I can think of is to use semi-automatic mode (Mode A), with aperture priority. This is where the camera will automatically adjust the exposure. And this, combined with spot metering, so that it only evaluates the brightness of the moon and not the background, I think it could work. But there are so many things that I think could go wrong.

For example, as the moon is eclipsed, the exposure changes dramatically from one moment to the next. Or, in that same section, I expose for the shadows, while the bright light is blown out, etc.

I'm open to any advice you might have. Ideas on how to do this. If anyone plans to do the same with similar equipment, I'd love to hear your ideas.

Thank you all very much in advance,
Cheers from Chile!
Tomas.

Rule n.1 of Lunar Eclispes: none can predict their magnitude

Rule n.2: always bracket your exposures

Rule n.3: something won't work (that really applies to almost anything that is crtical and scarce)

Having said that I just want to ease your mind about one thing: there won't be a drastic change from penumbra to first contact to centrality, just a slow diminishing of light. All the time in the world to adjust exposure timing.

One thing though; whether the Moon will be in focus (are you planning to focus manually, I do hope?) and 2nd whether you want to capture the stars behind or not. The last bit relates to the maximum exposure length  you can take before star trailing if you use lunar rate (which will be still drfiting in the Dec anyway).

Good luck!