Need help improving my Andromeda images (DSLR based)

[INeedSomeHelp]

Hi all,

my first serious attempt to take a good image of andromeda with my normal DSLR + photography gear. However, my image came out poorly and I could use some tips. I have followed this really excellent tutorial: https://www.youtube.com/watch?v=pXcRKoxTPVg&t=1233s

I used:

Canon 80D, stock (iso 3200 and a shutter of 2s)

Canon 100mm f2.8 Macro USM (@f2.8)

Tripod and the internal intervalometer of my camerabody

SiriL for the processing

I took:

around 370 light frames (should have been more but something went wrong..) every 80 pictures I reframed and refocused on the andromeda galaxy, then took another 80 pictures.

75 bias frames

10 dark frames

25 flat frames

Regarding the ISO, the tutorial mentions a chart (https://www.photonstophotos.net/Charts/RN_e.htm) and picking the ISO that marks the start of this chart "levelling off". For my camera (80D) that would be at ISO 5091. Isn't that an extremely high ISO? For this reason I used 3200, which is the same ISO used in the tutorial. The image shown here is directly after SiriL-based stacking.

[alacant]

1 hour ago, INeedSomeHelp said:

image shown here is directly after SiriL

Hi

Really? It looks as if it's been stretched,

Should be easy to diagnose. How about posting -a link to- the .tif or .fits from the Siril working directory? There's only around 10 minutes of exposure, but there maybe something... 

Cheers

Edited July 23, 2021 by alacant

[Alien 13]

I too have an 80D and find the best ISO is between 100-400 due to the camera being relatively ISO invariant, see this site..

Alan

 

Edited July 23, 2021 by Alien 13

[Astro Noodles]

1 hour ago, INeedSomeHelp said:

Hi all,

my first serious attempt to take a good image of andromeda with my normal DSLR + photography gear. However, my image came out poorly and I could use some tips. I have followed this really excellent tutorial: https://www.youtube.com/watch?v=pXcRKoxTPVg&t=1233s

I used:

Canon 80D, stock (iso 3200 and a shutter of 2s)

Canon 100mm f2.8 Macro USM (@f2.8)

Tripod and the internal intervalometer of my camerabody

SiriL for the processing

I took:

around 370 light frames (should have been more but something went wrong..) every 80 pictures I reframed and refocused on the andromeda galaxy, then took another 80 pictures.

75 bias frames

10 dark frames

25 flat frames

Regarding the ISO, the tutorial mentions a chart (https://www.photonstophotos.net/Charts/RN_e.htm) and picking the ISO that marks the start of this chart "levelling off". For my camera (80D) that would be at ISO 5091. Isn't that an extremely high ISO? For this reason I used 3200, which is the same ISO used in the tutorial. The image shown here is directly after SiriL-based stacking.

It is Alpheratz and surrounding region?

From where I am located (North Yorkshire), Andromeda is still low in the sky. As we don't have full astro darkness, I have been staying away from Andromeda because the sky is too light. I think this is what your problem is.

[Astro Noodles]

6 minutes ago, Alien 13 said:

I too have an 80D and find the best ISO is between 100-400 due to the camera being relatively ISO invariant, see this site..

Alan

 

I have been experimenting at length with my 1100D and have found that the 'sweet spot' for me is iso 1600. I have been worried that I am doing something wrong and should be looking for iso 400-800 but I can't get the required signal from those. Having looked at the link you have posted, it says best iso for 1100d is 1600. so I'm pleased. 😁 Thanks for that Alan.

[Alien 13]

12 minutes ago, Astro Noodles said:

I have been experimenting at length with my 1100D and have found that the 'sweet spot' for me is iso 1600. I have been worried that I am doing something wrong and should be looking for iso 400-800 but I can't get the required signal from those. Having looked at the link you have posted, it says best iso for 1100d is 1600. so I'm pleased. 😁 Thanks for that Alan.

No problem, my old 650D was similar in that the optimum was between 800-1600 ISO as it is with most Canon cameras, the 80D is a strange beast..

Alan

[Chefgage]

4 hours ago, INeedSomeHelp said:

Hi all,

my first serious attempt to take a good image of andromeda with my normal DSLR + photography gear. However, my image came out poorly and I could use some tips. I have followed this really excellent tutorial: https://www.youtube.com/watch?v=pXcRKoxTPVg&t=1233s

I used:

Canon 80D, stock (iso 3200 and a shutter of 2s)

Canon 100mm f2.8 Macro USM (@f2.8)

Tripod and the internal intervalometer of my camerabody

SiriL for the processing

I took:

around 370 light frames (should have been more but something went wrong..) every 80 pictures I reframed and refocused on the andromeda galaxy, then took another 80 pictures.

75 bias frames

10 dark frames

25 flat frames

Regarding the ISO, the tutorial mentions a chart (https://www.photonstophotos.net/Charts/RN_e.htm) and picking the ISO that marks the start of this chart "levelling off". For my camera (80D) that would be at ISO 5091. Isn't that an extremely high ISO? For this reason I used 3200, which is the same ISO used in the tutorial. The image shown here is directly after SiriL-based stacking.

I have just platesolved this image and you are not pointing at Andromeda. 

Here is the platesolved image. You are not far off but Andromeda is not in your image.

 

[Chefgage]

The star you are centred on is Alpheratz. You can see Alpheratz in this image from skysafari. Andromeda is a bit further up.

Edited July 23, 2021 by Chefgage

[INeedSomeHelp]

16 hours ago, Alien 13 said:

I too have an 80D and find the best ISO is between 100-400 due to the camera being relatively ISO invariant, see this site..

Alan

 

Thanks, so I will shoot for 400 ISO then... Cheers for the tip! Do you think that at 100mm f2.8, a 1s exposure and around 1000 photo's (so thats 1000s. of total exposure at ISO 400) with a half moon is good enough?

[INeedSomeHelp]

16 hours ago, Astro Noodles said:

It is Alpheratz and surrounding region?

From where I am located (North Yorkshire), Andromeda is still low in the sky. As we don't have full astro darkness, I have been staying away from Andromeda because the sky is too light. I think this is what your problem is.

You are right, I am accidentally looking Alpheratz, as others have also deduced. I still think M31 might be in my image somewhere I am attempting to upload the .fit but my internet is poor. I am now in Italy (central), what does that mean for Andromeda positioning? It's also quite low right? The moon is behind me when pointing at M31 in the east but to the east there is some light pollution from distant cities.  Do you think I should also stay away from M31? What about switching to a nebulae? Is there a nebulae more easily photographed with these circumstances? I also have a 50mm f1.8 lens, perhaps there are better plans for me?

[INeedSomeHelp]

13 hours ago, Chefgage said:

The star you are centred on is Alpheratz. You can see Alpheratz in this image from skysafari. Andromeda is a bit further up.

Thank you, you are totally right!

[INeedSomeHelp]

13 hours ago, Chefgage said:

I have just platesolved this image and you are not pointing at Andromeda. 

Here is the platesolved image. You are not far off but Andromeda is not in your image.

 

Thanks, since I centered on Alpheratz with a 100mm lens, I still think M31 is somewhere in my image, outside the cropped part that I showcase here. I will try to find it.

[INeedSomeHelp]

17 hours ago, alacant said:

Hi

Really? It looks as if it's been stretched,

Should be easy to diagnose. How about posting -a link to- the .tif or .fits from the Siril working directory? There's only around 10 minutes of exposure, but there maybe something... 

Cheers

Based on other posts it seems that I am looking at the wrong location (but with a 100mm lens, so perhaps M31 is still somewhere in the image). I couldn't upload the .fit as my internet connection doesn't cooperate. BTW, you are correct, I have selected "autostretch", otherwise the image is just black. I am attempting to upload either a .fit or .tif file, but my internet here is quite bad. So what I did is take a "snapshot" of the full image in .png, could you show me where to crop it? If I crop it and send you that .TIF, perhaps my connection can cope.

I should say that we have full moon here, and that is of-course not helping. In about 6 days we have a "half moon", hopefully that will improve the light pollution.

Edited July 24, 2021 by INeedSomeHelp
Forgot file

[Chefgage]

1 hour ago, INeedSomeHelp said:

Thanks, since I centered on Alpheratz with a 100mm lens, I still think M31 is somewhere in my image, outside the cropped part that I showcase here. I will try to find it.

This screen shot shows the field of view using a 75mm lens (blue box) using a similar camera sensor size. So a wider field of view than you are using, so I would have thought Andromeda would still be out of view unfortunately.

Edited July 24, 2021 by Chefgage

[happy-kat]

With your sensor size and a 100mm lens then depending which direction you point in your exposure range could be from 4 seconds to 1 second. Try taking a test shot at the start of your target and work from 4 seconds and down, work out when star trailing is acceptable then use that exposure for that night on the target used.

Areas of the milky way such as the summer triangle using a wider lens like 50mm are great trip take lots off and stack.

As a rough guide on your camera 400/lens focal length gives a starting exposure to try from.

[Astro Noodles]

1 hour ago, INeedSomeHelp said:

You are right, I am accidentally looking Alpheratz, as others have also deduced. I still think M31 might be in my image somewhere I am attempting to upload the .fit but my internet is poor. I am now in Italy (central), what does that mean for Andromeda positioning? It's also quite low right? The moon is behind me when pointing at M31 in the east but to the east there is some light pollution from distant cities.  Do you think I should also stay away from M31? What about switching to a nebulae? Is there a nebulae more easily photographed with these circumstances? I also have a 50mm f1.8 lens, perhaps there are better plans for me?

From central Italy you should be ok with Andromeda. 🙂

[INeedSomeHelp]

50 minutes ago, Chefgage said:

This screen shot shows the field of view using a 75mm lens (blue box) using a similar camera sensor size. So a wider field of view than you are using, so I would have thought Andromeda would still be out of view unfortunately.

In some way that is good news, then I can try again!

[INeedSomeHelp]

37 minutes ago, happy-kat said:

With your sensor size and a 100mm lens then depending which direction you point in your exposure range could be from 4 seconds to 1 second. Try taking a test shot at the start of your target and work from 4 seconds and down, work out when star trailing is acceptable then use that exposure for that night on the target used.

Areas of the milky way such as the summer triangle using a wider lens like 50mm are great trip take lots off and stack.

As a rough guide on your camera 400/lens focal length gives a starting exposure to try from.

Good tip, I think that sitting around 2s. or perhaps 3s. is achievable. Then my new plan:

- actually find the M31....

- around ISO 400

- 2-4 second exposures

- wide open at f2.8

- frame M31 by taking a 10-15s test shot to see if it is in focus/in my FOV

- take 50-80 images and refocus, repeat x amount of times

- take the calibration images

 

[Astro Noodles]

7 minutes ago, INeedSomeHelp said:

Good tip, I think that sitting around 2s. or perhaps 3s. is achievable. Then my new plan:

- actually find the M31....

- around ISO 400

- 2-4 second exposures

- wide open at f2.8

- frame M31 by taking a 10-15s test shot to see if it is in focus/in my FOV

- take 50-80 images and refocus, repeat x amount of times

- take the calibration images

 

In central Italy it should be fully dark at about 22:30. So you can use the time before that to take your test shots.

[happy-kat]

2.8 may not be the best aperture to use, try a test shot and compare to a stopped down shot. Edge and corner star shape can be distorted wide open depending on lens but hopefully as you are using the 100mm macro lens it's pretty flat.

When focusing it can help to not focus on a star dead centre but rather use one where one of the thirds intersects, this can improve general focus.

 

[alacant]

2 hours ago, INeedSomeHelp said:

could you show me where to crop it?

Hi

No need as @Chefgage's plate solve shows you missed it. Good luck with the next attempt. Now you know what you're looking for, it should be easy to frame with a 100mm lens.

The .fits will looks very dark, almost black apart from perhaps some of the brighter stars. Upload to the SGL server may be slow. It seems to depend upon where you are rather than the speed of your connection. Best to upload to say, Google Drive and post a link back here.

Cheers

[INeedSomeHelp]

1 hour ago, Astro Noodles said:

In central Italy it should be fully dark at about 22:30. So you can use the time before that to take your test shots.

Do you mean calibration shots for the test shots? Or already start shooting M31 to try and localize it? And if I am in central Italy, which I am, and Alpheratz is to my east, I should go to the left (north) and up, correct?

[Astro Noodles]

All of the above. 🙂

If you go from Alphertaz to the next bright star to the left, which is Mirach. Straight up from Mirach, you will see a fainter star Mu Andromedae. If you draw a line between Mirach and Mu Andromedae and extend for an equal length, then you will have the Andromeda Galaxy in frame.

I recommend Stellarium which is a free planetarium app you can get for phone or tablet. it makes finding things so much easier. 

[happy-kat]

Could use binoculars at night to get familiar with the target area.

Astrometry.net is free platesolving

 

Edited July 24, 2021 by happy-kat

[Malpi12]

+1 for Stellarium

In your uncropped pic you can also see delta Andromeda bottom left.
I have set my Stellarium to approximate your field of view and superimposed your pic upon a mozaic of 2 Stellariums which shows that you were nearly there just a frame away !

The stellarium underneath:

If you re-aquire Alpheraz - then star-hop by moving it to top right with delta near the middle you should be able to get Mirach near the bottom left.

Hop again so that Mirach in the the bottom right.
Your target should now be in the top-middle,

I do this at the camera on the LCD with 2 or 4 sec single exposures with ISO 3200 or 6400 in my northern twilight so you should be ok. (mag4 stars show up well) 
Then centre the target, re--adjust to your stacking ISO and fire away
 

 

Edited July 24, 2021 by Malpi12