My first galaxy (M51) and nebula (M97) images

[lrt75914]

Hi guys,

 

Afters months of waiting and praying for better weather, I finally managed to capture my first deep sky images. Keep in mind that these are test images to see how my autoguider works and how well my DSLR (alpha 55) handles astro-imaging. The images (especially M97) are very noisy and I didn't bother to take any dark-/bias-/flat-frames. Given the circumstances, however, I am quite happy with how the images turned out. Any criticism, as always, is greatly appreciated.

M97 (11 Light Frames X 10 min):

M51 (15 Light Frames X 4 min):

 

Equipment Used:

• Skywatcher Explorer 200-PDS
• Skywatcher AZ-EQ 6 GT
• Sony Alpha 55
• Lacerta MGEN II (9x50 Guide Scope)
• Mercedes Benz A Class
• My Dad

Software Used:

• PixInsight 1.8
• AstraImage 5.0

[hjw]

I am impressed. For first images these are better than good. With a DSLR and exposure times over 3 minutes I found that darks are required. The sensor is heating up during the longer exposures and causes artifacts. With my camera, 10 min is the limit at which darks don't help anymore. Other than this - a really great start.

Nur weiter so...

HJ

[Galactic Wanderer]

28 minutes ago, lrt75914 said:

Hi guys,

 

Afters months of waiting and praying for better weather, I finally managed to capture my first deep sky images. Keep in mind that these are test images to see how my autoguider works and how well my DSLR (alpha 55) handles astro-imaging. The images (especially M97) are very noisy and I didn't bother to take any dark-/bias-/flat-frames. Given the circumstances, however, I am quite happy with how the images turned out. Any criticism, as always, is greatly appreciated.

M97 (11 Light Frames X 10 min):

M51 (15 Light Frames X 4 min):

 

Equipment Used:

• Skywatcher Explorer 200-PDS
• Skywatcher AZ-EQ 6 GT
• Sony Alpha 55
• Lacerta MGEN II (9x50 Guide Scope)
• Mercedes Benz A Class
• My Dad

Software Used:

• PixInsight 1.8
• AstraImage 5.0

Very well done indeed. I had my first imaging session yesterday of M13. I was quite impressed with the result. These are great! Next clear night Im going to try M51 and m27!

[lrt75914]

48 minutes ago, hjw said:

I am impressed. For first images these are better than good. With a DSLR and exposure times over 3 minutes I found that darks are required. The sensor is heating up during the longer exposures and causes artifacts. With my camera, 10 min is the limit at which darks don't help anymore. Other than this - a really great start.

Nur weiter so...

HJ

Thank you for your compliment. I'm not quite new to astro-imaging as I had already taken 3 wide field images with my dad's DSLR. It was my first time imaging with a telescope and the first time I was able to capture a galaxy, though. I was planning on taking dark frames, but my dad was starting to feel the cold and wanted to go home.   

 

44 minutes ago, Galatic Wanderer said:

Very well done indeed. I had my first imaging session yesterday of M13. I was quite impressed with the result. These are great! Next clear night Im going to try M51 and m27!

Thank you very much.  

[wimvb]

8 hours ago, lrt75914 said:

Thank you for your compliment. I'm not quite new to astro-imaging as I had already taken 3 wide field images with my dad's DSLR. It was my first time imaging with a telescope and the first time I was able to capture a galaxy, though. I was planning on taking dark frames, but my dad was starting to feel the cold and wanted to go home.   

 

Thank you very much.  

Very fine images. Guiding seems to work fine for you.

I think that it's about time you lure your father into this hobby as well (at least until you can borrow his Mercedes)

Or prepare him a thermos with something hot of course

[DougM43]

That's a super M51, I'm sat in the garden taking my first serious attempt at a deep sky image of that same Galaxy, if mine comes out half as good as yours I'll be more than pleased, we'll done.

Doug

[hjw]

13 hours ago, lrt75914 said:

Thank you for your compliment. I'm not quite new to astro-imaging as I had already taken 3 wide field images with my dad's DSLR. It was my first time imaging with a telescope and the first time I was able to capture a galaxy, though. I was planning on taking dark frames, but my dad was starting to feel the cold and wanted to go home.   

 

You don't have to take your darks on the spot. When you get home, leave the camera in the garage with a lens cap on and take the darks. In the past I have put my camera in the fridge over night to take darks. Temperature should be close but does not have to be spot on.

Cheers

HJ

[lrt75914]

22 hours ago, wimvb said:

Very fine images. Guiding seems to work fine for you.

I think that it's about time you lure your father into this hobby as well (at least until you can borrow his Mercedes)

Or prepare him a thermos with something hot of course

Thank you :). The guiding system is absolutely amazing. I'm not quite sure how good my tracking error/polar alignment is, 'though. I've tried to make any sense of the guiding data, but so far I can't wrap my head around the result files. These seem to be the best/worst guided exposures:

 

My dad keeps telling me about his 'astronomy' club in high school and how any object they looked at through their telescope always looked like a tiny, blurry little dot. Apparently their 'astronomy' club was just a way for them to be allowed to stay up late and keep their parents of their backs.  Seeing how you can actually take an image of a galaxy, however, has him stunned and amazed, so there might still be hope for him after all.

20 hours ago, DougM43 said:

That's a super M51, I'm sat in the garden taking my first serious attempt at a deep sky image of that same Galaxy, if mine comes out half as good as yours I'll be more than pleased, we'll done.

Doug

This is hobby is something else. I have never felt so exhilarated before. Let's hope your imaging session was a success as well.

17 hours ago, hjw said:

You don't have to take your darks on the spot. When you get home, leave the camera in the garage with a lens cap on and take the darks. In the past I have put my camera in the fridge over night to take darks. Temperature should be close but does not have to be spot on.

Cheers

HJ

I let my camera cool down to ambient temperatures and am taking some dark frames as we speak. Let's see if that will improve the images. I'm not sure, however, whether my mother will appreciate me putting a camera in her fridge.

[wimvb]

I don't use guiding myself, so I'm really not in a position to advise you. One of your screen shots shows a tracking error of 0.88 arc seconds in RA, and 0.5 arc seconds in Dec. I think that is quite good. The other plot shows a similar small tracking error in Dec, but a much larger (3.44 arc secs) in RA. The plot of the error in RA also shows a downward slope. Something drifted, despite guiding.

One thing I have learnt about guiding is that small random movements of a stars position is due to it's "blinking". Air flows in the atmosphere cause a star to blink and to appear to change it's position ever so slightly. This is seeing. If you use short exposures for guiding, then your system may try to correct for this. I think that may be the case for you. Most of the correcions that your guiding system made seemed random. What you should try to achieve by guiding, is correction of imperfect movements of the mount, and this is most likely some kind of slow drift.

You can have a look at this: http://openphdguiding.org/Analyzing_PHD2_Guide_Logs.pdf

It's not your guiding system, but it may provide more information on guiding and its pitfalls.

Maybe I'm totally off here, and somebody can correct me.

[lrt75914]

57 minutes ago, wimvb said:

I don't use guiding myself, so I'm really not in a position to advise you. One of your screen shots shows a tracking error of 0.88 arc seconds in RA, and 0.5 arc seconds in Dec. I think that is quite good. The other plot shows a similar small tracking error in Dec, but a much larger (3.44 arc secs) in RA. The plot of the error in RA also shows a downward slope. Something drifted, despite guiding.

One thing I have learnt about guiding is that small random movements of a stars position is due to it's "blinking". Air flows in the atmosphere cause a star to blink and to appear to change it's position ever so slightly. This is seeing. If you use short exposures for guiding, then your system may try to correct for this. I think that may be the case for you. Most of the correcions that your guiding system made seemed random. What you should try to achieve by guiding, is correction of imperfect movements of the mount, and this is most likely some kind of slow drift.

You can have a look at this: http://openphdguiding.org/Analyzing_PHD2_Guide_Logs.pdf

It's not your guiding system, but it may provide more information on guiding and its pitfalls.

Maybe I'm totally off here, and somebody can correct me.

Thank you very much for the advise and the link. I'm sure it will come in handy on the next cloudless weekend - which will probably in 2017 if the last 5 months are anything to go by.

 

 

New calibrated image:

[Petehog72]

On 08/05/2016 at 14:15, hjw said:

I am impressed. For first images these are better than good. With a DSLR and exposure times over 3 minutes I found that darks are required. The sensor is heating up during the longer exposures and causes artifacts. With my camera, 10 min is the limit at which darks don't help anymore. Other than this - a really great start.

Nur weiter so...

HJ

These are fantastic, ive just purchased the celestron 8se and sadly had rubbish weather since getting it, I carnt wait to start taking pics like these, admittedly its a big learning curve for me as im a novice but very excited to get started and learn  well done these are great for a 1st  

[hjw]

OK one last comment from my side and I promise I'll shut up...

As I mentioned before I am impressed with your picture, however the color balance is a bit off. It is very common to get a green shade in your picture in fact so common that one clever guy (or girl?) made a macro for Photoshop called Hasta la Vista Green or HLVG in short.

When applied to your image (and I used the medium setting) you get something like this:

Don't take it as a criticism - your are doing really well!

Cheers

HJ

[lrt75914]

11 hours ago, Petehog72 said:

These are fantastic, ive just purchased the celestron 8se and sadly had rubbish weather since getting it, I carnt wait to start taking pics like these, admittedly its a big learning curve for me as im a novice but very excited to get started and learn  well done these are great for a 1st  

Ahhh, the infamous buyers curse. Happens to me all the time. I still have a jet rc plane that hasn't received it's maiden flight, despite buying last summer. XD Let's hope the weather will pick up in the coming monts.

7 hours ago, hjw said:

OK one last comment from my side and I promise I'll shut up...

As I mentioned before I am impressed with your picture, however the color balance is a bit off. It is very common to get a green shade in your picture in fact so common that one clever guy (or girl?) made a macro for Photoshop called Hasta la Vista Green or HLVG in short.

When applied to your image (and I used the medium setting) you get something like this:

[...]

Don't take it as a criticism - your are doing really well!

Cheers

HJ

Neat. I was wondering why my picture still had this ugly green tint after color calibrating it with PixInsight. Thank you for that tip, I really appreciate it. Keep the 'criticism' coming, there is no better way for me to learn from my mistakes.  

I'm still struggling with the image noise, though. Next time I'll take a couple of more light frames and maybe use my dads DSLR. I have a feeling that my Sony alpha 55 is a big part of that particular problem.

 

 

[Starwiz]

Very nice images.  I only hope I can do half as well when I start with deep sky imaging.  

John

[toilandtrouble123]

These are your first DSO shots?!?! Jealous or what!!! Well done! I'm inspired

[Benno]

Excellent first attempt, very nice indeed.

[cdh79]

great images, especially for first ones

 

when using pixinsight, check out SCNR for getting rid of the green

[Astrosurf]

Cracking images! I won't show you my first one! 

Alexxx

[RSM]

On 10 May 2016 at 23:15, lrt75914 said:

Ahhh, the infamous buyers curse. Happens to me all the time. I still have a jet rc plane that hasn't received it's maiden flight, despite buying last summer. XD Let's hope the weather will pick up in the coming monts.

Neat. I was wondering why my picture still had this ugly green tint after color calibrating it with PixInsight. Thank you for that tip, I really appreciate it. Keep the 'criticism' coming, there is no better way for me to learn from my mistakes.  

I'm still struggling with the image noise, though. Next time I'll take a couple of more light frames and maybe use my dads DSLR. I have a feeling that my Sony alpha 55 is a big part of that particular problem.

 

 

Brilliant first attempts. I'm keen to have a go at M97 myself sometime soon. As for the noise issue, as you are guiding, try and dither (move the scope position slightly) between each sub frame. My guide system allows me to do this automatically (MGEN), I think other guiders allow the same. I found this was a big step forwards in reducing noise. Also, more subs will help (taken over different nights will help as long as exposure time is the same). Finally I mask the galaxies and stars and use a fairly strong noise reduction to effectively blur out the background noise. I use pixinsight for processing and TGV denoise routine. 

Good luck  

[Mrblotzer]

one of the better shots period! nice job!

[lrt75914]

On 10. Mai 2016 at 00:34, Starwiz said:

Very nice images.  I only hope I can do half as well when I start with deep sky imaging.  

John

On 15. Mai 2016 at 01:23, toilandtrouble123 said:

These are your first DSO shots?!?! Jealous or what!!! Well done! I'm inspired

On 16. Mai 2016 at 20:59, Benno said:

Excellent first attempt, very nice indeed.

On 17. Mai 2016 at 15:01, Astrosurf said:

Cracking images! I won't show you my first one! 

Alexxx

On 21. Mai 2016 at 08:40, Mrblotzer said:

one of the better shots period! nice job!

 

Thank you very much guys .

 

On 17. Mai 2016 at 11:19, cdh79 said:

great images, especially for first ones

 

when using pixinsight, check out SCNR for getting rid of the green

The more I learn about PixInsight the more I love that program. Thank you for that tip!

 

On 20. Mai 2016 at 12:15, RSM said:

Brilliant first attempts. I'm keen to have a go at M97 myself sometime soon. As for the noise issue, as you are guiding, try and dither (move the scope position slightly) between each sub frame. My guide system allows me to do this automatically (MGEN), I think other guiders allow the same. I found this was a big step forwards in reducing noise. Also, more subs will help (taken over different nights will help as long as exposure time is the same). Finally I mask the galaxies and stars and use a fairly strong noise reduction to effectively blur out the background noise. I use pixinsight for processing and TGV denoise routine. 

Good luck  

Do you, by any chance, also use a 9x50 finder scope with your MGEN? I've looked at the random displacement option on my unit but wasn't sure about the pixel displacement setting. Since I didn't know what value is appropriate for my setup I disabled it for the time being but I will definitely use it on my next attempt.

I gave the SCNR and HDRWaveletTransform module in PixInsight a try. As far as I am concerned this is the best I could do with the subs I captured:

It's a subtle difference but I think the HDRWaveletTransform brought out a little bit more shadow and highlight detail in the galaxy. Here is a comparison between a single sub and the final image.

 

[dant]

Really nice shots