Astrophotography

There isn’t really any current place here to just talk about what is, IMO, one of the most amazing things to talk about. So I’m making it. Astrophotography is taking pictures of stuff in the sky. No idea tbh if there are many people here that also do it.

I figure that this thread can be a place to talk about it, give advice, and discuss the images that we produce. So I guess I will start it off by explaining my setup and some of the images I have taken.

I have been doing astrophotography for a few months now, though only deep sky for a month. I use a pretty generic 130/650 newt, with a Uranus-C camera, and I am untracked currently, and in B6 light pollution.

My first DSO was of course, the Orion Nebula. It’s a star forming region with very bright hydrogen emissions, making it an easy target.


Since it was my first try, the data sucked. I wasn’t collimated, didn’t get as much data as I would have liked to, etc. I look forward to revisiting the Orion Nebula with better gear, like an OSC triband filter

One of my more recent (and better) images that I took is a mosaic of the Whale and Hockey Stick Galaxies. These are interacting galaxies that have caused the hockey stick like formation.


This is much better data, and you can even see slight coloration in the core of the whale galaxy, which is more visible with increased saturation.

Anyways that’s about all for me, what about you?

10 Likes

Those looks very nice! I’ve always wanted to do astrophotography, it seems awesome but I don’t have the necessary equipment to do so. Are you using software to refine the images? I once saw somebody on YouTube using some kind of assisting app, it can even remove the light pollution and lets you do astrophotography in the city!

1 Like

Yeah Ill explain the steps.

I capture images using Fire capture, but it doesn’t matter what you use they all act basically the same.

So first I stack images in Deep Sky Stacker. I use KS clipping method of stacking. Stacking is a way of combining many (2-10k since I’m not tracked) exposures to remove the noise caused in the sensor in each exposure. It is pretty much required to image anything untracked, because each sub-exposure has to be so short (<.5s) to avoid star trails.

I import the stacked image to Siril and do a few steps.

Color calibrate background and a star with a B-V of around .5 to .6, this helps remove skyglow by neutralizing the background color (typically green) and helps negate the uneven sensitivity of the sensor across specifically the blue wavelengths, which otherwise produces overwhelmingly orange star colors.

I will then typically do a background extraction, which removes any gradients and helps light pollution as well.

The final step is then stretching, which makes the DSO actually visible, because in an unstretched image it is very dim. Its similar to increasing exposure on an image, but a bit more complicated as it isnt typically a linear transformation.

After Siril I sometimes use gimp to finish editing

2 Likes

Here is one of my latest results.


NGC 2403 & 2404 are a galaxy and the top left largest Nebula.

This is 70min integration time which is inconveniently the limit if I want a full-size image, now I can crop like I did in post here, but it’s super annoying, because I wouldn’t get background galaxies like these (just the biggest and brightest, there are others)

image
image

On the lonesome background galaxy there we can barely see a slight spiral, better visible when desaturated and brightened up. (Red reference drawing for help noticing the spiral)

image

So yeah, hopefully this weekend will be slightly clear, and I can image something, probably m101 or m51.

Monday update!
The weekend has past, and while I didn’t really image much I was trying out live stacking, which is when images are stacked straight off the camera.


The main galaxies here are ngc 3227 and 3226, off to the right is ngc 3222. There are dozens of other galaxies in this image though, see if you can spot the fuzzy dots and lines, quite a few of the “stars” arent stars at all!
I also did some more niche imaging…

Every streak in this image is a cosmic ray that hit my sensor over about an hour! Pretty neat huh?

5 Likes