Will stacking more images produce more detail in this galaxy photo?

Question

I've just started doing a bit of astrophotography and finally after the third night of trying I found my target, the Whirlpool galaxy. I'm pleased I've managed to capture it but I'm looking into how I can further the image, and the detail captured. This is the image I've captured:

The setup for this is:

Camera: Sony A77ii (APS-C)

Lens: Sigma 18 - 300mm f/3.5 - f/6.3

Light Frames: 103 exposures at 300mm f/6.3 ISO 3200 and exposed for 1 minute each. The camera was placed on a Move Shoot Move star tracker on a tripod

Dark Frames: 30

Bias Frames: 31

This was then stacked using DeepSkyStacker and processed slightly in Lightroom.

My question is would stacking another say 100 exposures on top of this bring out much more detail/reduce more noise? I realise my setup isn't exactly ideal for this sort of astrophotography but I'm interested to see if there's a way I can improve the image quality further, or if this is the sort of limit I can reach with what I currently have.

Answer 1

Stacking more images reduces noise to signal ratio, but don't add resolution or details.

In order to enhance resolution, my advice is to use a prime lense, instead of a zoom one. Even if it has less focal length.

In my personal experience, I get more details with a 80mm prime than with a 55-250mm at 200mm

Answer 2

Yes, but No.

Your question is will it produce more detail, and yes stacking more images will reduce noise which will let you see more detail. And at least as important, you are taking calibration frames. But this is all post processing.

Post processing will get you from to

Or from

But, it will never get you from to (Each first image is an unprocessed raw image. The latter are processed including stacking and calibration. The last image is from astrobin and is not mine.)

For that you will need a longer focal length. Image taking a photograph of the Eiffel tower from a mile away and expecting to stack a couple and crop it until you have a postcard perfect 8x10.

You either need to get a focal length appropriate for your target, or get a target appropriate for your focal length.

M31 is a great place to start with a 300mm if you want a galaxy. M42 is not only colorful but bright and as also a great target with 3oo and a DSLR.

Also, I can't tell for sure looking only at post processing, but your stars look big and I wonder if you are a little out of focus. Find focus is extremely hard with a DSLR - and harder to keep. Your stars a a little football shaped and your exposure might be a little longer than your tracking allows.

Answer 3

In my limited experience (back when Astrostack was the hot item, and using video captured at 640x480 with a webcam -- call it 1998 or so), stacking more frames will decrease the appearance of noise by averaging it away, but won't increase detail beyond about double the actual pixel resolution of the image (you only get that much because the image wanders a little over the pixel field, and the stacking software does sub-pixel alignment).

What you need in the above image to see more detail in the galaxy is probably higher magnification. If you can add a tele-converter to that lens without degrading the image quality, you may see some improvement, but otherwise, you'll just have to either invest in a telescope and polar tracking mount of some kind, or get a longer lens for your current setup. A high quality lens longer than 300 mm is likely to cost as much or more than a small refractor, so it's probably a toss-up -- ideally, you'd have the ability to test the telescope before buying, as some will have the resolution you need, and some won't.

As noted in another answer, the lens you're using is also part of the problem. Zoom lenses aren't the preferred kind for astrophotography; a super-zoom like your 18-300 probably has more than twenty elements, and every interface subtracts a little resolution and adds a little flare (reducing contrast, even with subjects like this).

It's likely that an inexpensive long prime such as a Tamron 500 mm with the right adapter to fit your camera would do at least as well. You'd get a larger image, have only (at most) five or six elements in the lens, and likely have better total light gathering (though partly offset by the higher magnification). You don't need the lens to support autofocus (you'll be at infinity at all times) or even auto aperture (you'll set it and forget it anyway). Lenses in that class can sometimes be had for less than the adapter to fit your camera's mount.

Answer 4

I tried DSS many times over the course of a year. I was delaying on getting APP. I finally took the dive and got APP and it's game changing. If you want to stack your photos and actually see results, I would recommend renting/buying APP. It makes all the difference.

I know this is an old post, but if you haven't found APP, I would try your stacking by using the 30 day trial and see the difference. When I did the trial I was too new to understand it all, so I wasted my trial. Don't wait years like me to see what APP can do.