Horsehead and Flame Nebula with my Dobsonian

[Smiller]

Hi Folks,

I’ve owned an Orion XT12G Goto Dobsonian for viewing, which I like.  Over the last 9 months or so, I decided to try a little deep sky with it.  It turns out it’s worked pretty well as long as I take short exposures (like 6-8 seconds).

Here’s an example shot over 3 hours with 8 second exposures.  I shot 1.5 hours with no filter and then 1.5 hours with a Dual Narrowband filter (IDAS NBZ) for better H-alpha clarity as I’m shooting from my light polluted suburban backyard.

Scope: Orion XT12G with Nexus 0.75x Reducer, Camera: ASI2400MC

Cheers!

 

Edited March 3, 2023 by Smiller

[dave34]

Very nice indeed.

[rl]

Excellent result.

Assuming an exposure can be made and read out in 10 seconds, that's over 1000 subs to stack and align over the 3 hours!

[Smiller]

5 hours ago, rl said:

Excellent result.

Assuming an exposure can be made and read out in 10 seconds, that's over 1000 subs to stack and align over the 3 hours!

It was actually about 1300-1400 I believe.  It took my laptop most of the next day to stack them.  That’s really the one big downside of short subs required by my Dob.

But once you understand it, you just get it stacking in the morning, check it a couple of times to make sure it’s going good, and come back later when it’s done.

 

Edited March 3, 2023 by Smiller

[Elp]

Excellent, just goes to show super long single exposures aren't really all that necessary as long as you make it up via the total stack.