M101 (Pinwheel Galaxy)

[vineyard]

Hello,

My first ever galaxy photo!  When I look at some of the other M101s out there, it makes me want to hide but hey you've got to start somewhere.

What would be the first line of attack to improve this image: change the processing, or take longer lights, or have a cooled camera or a camera with a different pixel pitch?

Thank you for any suggestions & stay safe,

Vin

(PS I really should have cropped the top right hand corner out but hey ho)

[wimvb]

Nice!

14 minutes ago, vineyard said:

What would be the first line of attack to improve this image: change the processing, or take longer lights, or have a cooled camera or a camera with a different pixel pitch?

More data. People use all kinds of gear, but what will improve your image most is to increase the amount of data. 

[wimvb]

20 minutes ago, vineyard said:

PS I really should have cropped the top right hand corner out but hey ho

Use pixinsight dbe or abe for that. 

[old_eyes]

4 minutes ago, vineyard said:

Hello,

My first ever galaxy photo!  When I look at some of the other M101s out there, it makes me want to hide but hey you've got to start somewhere.

What would be the first line of attack to improve this image: change the processing, or take longer lights, or have a cooled camera or a camera with a different pixel pitch?

Thank you for any suggestions & stay safe,

Vin

(PS I really should have cropped the top right hand corner out but hey ho)

it is a pretty fantastic start. You can see a lot of the key features. Well done.

You certainly need more data. A lot of thje M101 detail is quite faint. Those amazing images you have seen often use hours and hours of data. One I was involved in with @ollypenrice used 2hours each of separate red, green and blue. 4 hours of luminance and 100mins of H-alpha. Getting on for 12 hours of data collection with a cooled camera, great optics and a very clear sky. But you can get great images with a lot less data than that.

So more data.

Cooled camera helps, processing can get more out of an image, but the essence is data.

The thing that transformed my imaging was getting a setup and software where I could revisit the same target over several nights. When I was trying to get alll the data in one night with UK weather, I was always struggling. Now I have learned how to get back to the same view more or less reproducibly the images are better. Not as good as the masters, but better.

I don't know EKOS, but tools like APT can use platesolving to take you back to to exactly the same point in the sky, and have a way of overlaying a previous image with a current one so that you can get the camera alignment the same. Plate solving is magic - pure magic! If you are not using it, learn how.

But be very pleased with that image. One of my very early galaxy pics when learning to use my first camera was of M51. It wasn't great - not enough data, not focused, poor guiding etc, but I had accidentally captured supernova SN2011dh! that made it very special. Still the image I pull out to astound friends today.

[wimvb]

6 minutes ago, old_eyes said:

I don't know EKOS, but tools like APT can use platesolving to take you back to to exactly the same point in the sky, and have a way of overlaying a previous image with a current one so that you can get the camera alignment the same. Plate solving is magic - pure magic! If you are not using it, learn how.

Ekos does the same. Alignment to within 10 arcseconds is possible, if your mount allows it.

Besides more data, guiding should be on your short list.

[vineyard]

Thanks both - for the kind words & the suggestions.  Yes to all of the tips!  I do have a guidescope - lets see how good the alignment gets.  I just got the HEQ5Pro second hand from a fellow SGLer and after a weird first night, last night was the second go and I was just hopping looking at different targets and (fingers crossed) it seemed to be doing what it was meant to (and quite well - I even tried some 2 min exposures and without guiding they were - by my eyes - pretty steady).  Crikey re the 12 hours but looking at my image & others I can see where the extra data comes in!  I wish I had a permanent setup but I've found a good spot at the bottom of the garden (and - last night at least - the wifi reached there to be able to sit inside and control things ).  At least Uma typically tends to be quite high & always around, so yes there's no reason for me to not try adding more data.

Sadly staying indoors tonight as running some aches, but good luck if you're out - stay warm & safe.

Cheers,

Vin

[vineyard]

Wow Kev the difference between the two images is palpable 👏🏽 That extra data makes such a huge difference. And that's with an unmodded DSLR - yikes!  The galaxy is so much more delicate in your image, whereas looking over-extracted to within an inch of its life in mine 😂

(Btw I was reading more about that galaxy - 1 trillion stars - and those photons started their journey in the early Meiocene period on Earth when apes were just evolving 😲)

Cheers

[wimvb]

6 hours ago, vineyard said:

And that's with an unmodded DSLR - yikes!

For galaxies, the fact that a camera is modded or not, doesn't make much of a difference, unless the galaxy contains many Ha areas.

6 hours ago, KevS said:

There are some very faint distant background objects in the general area of M101, that are way beyond the resolution of amateur kit where the light has been traveling for 1/2 the life of the universe

Not necessarily so. This has more to do with sky quality and perseverance.

This image, with 11.5 hrs of integration time, contains a galaxy cluster at a distance of some 5.4 billion light years. Not exactly half the universe's age, but close. And that's with a £1000 scope and £900 camera

https://www.astrobin.com/jd2hjn/C/?nc=user

https://vizier.u-strasbg.fr/viz-bin/VizieR-6?-out.form=%2bH%2bm&-source=J/MNRAS/392/1509&-corr=FK=Cluster&-out.max=9999&Cluster===ZwCl 0848.5%2b3341

[tomato]

That's a fine first galaxy, so many of the fundamentals, framing, focusing and tracking are good. The biggest single improvement will be more frames to stack, as already noted, this galaxy has quite a low surface brightness. 

I was advised to calibrate the ASI 178 with darks, flats and dark for flats (darks taken with the same duration as the flats), and this does some to give a better result than the darks/flats/bias approach.

[wimvb]

49 minutes ago, tomato said:

I was advised to calibrate the ASI 178 with darks, flats and dark for flats (darks taken with the same duration as the flats), and this does some to give a better result than the darks/flats/bias approach.

That's right. Because of amp glow, any lights, including flats, need to be dark calibrated with matching darks. Several people have also reported that the read pattern of these cameras can change over time. This makes using bias frames questionable. And since the bias signal is slready present in the darks, there's no need for using them if you don't scale your darks.