Beginner progress on M42

[Johns22]

I'm starting to feel like progress is being made in a few areas of my Astrophotography. Until January I had never took a photo on a DSLR camera or used photoshop nevermind a telescope!

These photos were taken on 15th March 2020, using a Skywatcher 200P on a EQ5 Goto Mount, a Canon 600D with Svbony CCD Filter and captured in NINA. Unguided (couldn't get new guidecam in focus) using Platesolve with ASTAP;

80 x 20" Lights - ISO800

40 x Bias - ISO800

30 x Darks - ISO800

Stacked in Deep Sky Stacker, edited in Photoshop 2020

Would very much appreciate any advice!

Edited March 18, 2020 by Johns22

[souls33k3r]

Now that is something spectacular. Well done you. Just keep at it and learn different processing techniques because the first two of the three hurdles (Knowing your gear and Image Acquisition) you're well on your way and the last hurdle which is processing skills, well truth be told that skill never stops. 

All the best. 

[PeterCPC]

Fantastic start. Now the fun and struggles begin. How do you focus? I recommend using a Bahtinov mask to nail the focus.

Peter

[Adreneline]

A very good start and one you should be well pleased with - excellent!

A lesson I learnt early on was not to make the surrounding space too black. I was given excellent advice that if you can identify a region which should represent background space then set the RGB levels to roughly 23:23:23. Your image is quite clipped at the black end of the histogram, in fact the histogram is well pressed up against the end stop! If you set it back I think you will reveal far more of the nebulosity around M42.

Your histogram looks like the first of these two whereas you want the black point to move to the right as below:

 

Doing that starts to reveal more precious data that you have inadvertently suppressed:

I think you have a far better and more revealing image lurking in your data.

HTH

Adrian

P.S. If you share your final stacked and calibrated tif from DSS I'm sure someone will want to have a go to see what they can find. Another piece of advice is don't use DSS to make any adjustments to the image.

 

Edited March 18, 2020 by Adreneline
Clarification

[Johns22]

5 hours ago, PeterCPC said:

Fantastic start. Now the fun and struggles begin. How do you focus? I recommend using a Bahtinov mask to nail the focus.

Peter

Thanks Peter - I use a Bahtinov mask too.

[Johns22]

4 hours ago, Adreneline said:

A very good start and one you should be well pleased with - excellent!

A lesson I learnt early on was not to make the surrounding space too black. I was given excellent advice that if you can identify a region which should represent background space then set the RGB levels to roughly 23:23:23. Your image is quite clipped at the black end of the histogram, in fact the histogram is well pressed up against the end stop! If you set it back I think you will reveal far more of the nebulosity around M42.

Your histogram looks like the first of these two whereas you want the black point to move to the right as below:

 

Doing that starts to reveal more precious data that you have inadvertently suppressed:

I think you have a far better and more revealing image lurking in your data.

HTH

Adrian

P.S. If you share your final stacked and calibrated tif from DSS I'm sure someone will want to have a go to see what they can find. Another piece of advice is don't use DSS to make any adjustments to the image.

 

Wow - thanks Adrian, this is really helpful! I too noticed that the black point was right across but I didn't want to blow the centre out anymore than it already is. Great info in your post that I will have a go at.

I'll load the .tif file later tonight for anyone who wants to try their processing skills on it - it would be really valuable to see what others can do with it too.

Thanks again.

[Adreneline]

1 hour ago, Johns22 said:

I didn't want to blow the centre out anymore than it already is.

Well you could always try creating a duplicate layer and using the Burn Tool to try to recover things a little. I usually set mine to midtones or highlights with an exposure of 10% and craefully reduce and desaturate the burned out region. It's all part of the fun!

I'll look out for the tif file - it'll be something to do now we're confined to quarters!

Good luck!

Adrian

[Johns22]

Here is the original stacked tiff file for the above image. Feel free to process and share tips/tricks with me!

Autosave.tif

[Adreneline]

I found this challenging! There was a tricky gradient across the image which I found was quite difficult to suppress.

The image is stretched in PixInsight and then I removed the gradient (as best I could) in PS.

I did a bit of colour tweaking and noise reduction in PS

It is quite different to your original image - what do you think?

If you can take some Flats that would be advantageous.

Adrian

 

 

Edited March 18, 2020 by Adreneline
Clarification

[geeklee]

Definitely agree with @Adreneline some flats would help enormously with the vignetting (I think?) that's also contributing to difficult gradients

I've still got some around the sides, even after a generous crop. Worked through with PixInsight - stretched, then HDR MT for the core area and a few other light touches like colour and sharpening.  Not the full work flow 😅

I'm missing a lot of the darker dust that @Adreneline has picked up though.

[Adreneline]

@geeklee Really like your version Lee - I forgot all about using HDRM.

[geeklee]

1 minute ago, Adreneline said:

@geeklee Really like your version Lee - I forgot all about using HDRM.

By itself, it looked too strong but with a 50/50 blend using PixelMath it looked more natural. With some masking work, I'm sure it would be possible to get some more out of the image. 

[Johns22]

Thank guy's, that's very helpful. I have yet to take Flat's but am planning on doing so during the next session. Do you think that is the main issue with the gradient? I do suffer light pollution before 12am which is why I purchased the Svbony CCD filter. I wonder if it is this filter also causing the issue as I'm aware there are more expensive alternatives available. 

I really like both images above for different reasons - thanks so much for taking the time to show me how you would process the image. 😀

[Adreneline]

1 hour ago, Johns22 said:

I have yet to take Flat's but am planning on doing so during the next session.

Arguably flats are the most important of the calibration frames to take and whilst your're at it take dark-flats as well. If I calibrate in PI I use dark-flats instead of bias frames with my cmos ASI1600. Flats are primarily used to negate the effects of vignetting and to remove the effects of dust bunnies in the optical train.

The vast majority it would seem have to cope with some level of light gradient - I have an airport to the East - a town to the west - a city to the north and my own house to the west - I wonder sometimes why I bother! I have no experience of the Svbony filter - I have used an IDAS LP filter with an osc camera and with my dslr which I think helped.

HTH

Adrian

[geeklee]

5 hours ago, Johns22 said:

I have yet to take Flat's but am planning on doing so during the next session. Do you think that is the main issue with the gradient? I do suffer light pollution before 12am which is why I purchased the Svbony CCD filter.

Light pollution isn't a huge problem (relatively) post processing I find - due to the great tools out there - but combined with the vignetting I just couldn't get a stable background (had a go in APP as well).  Really good data in there though, so with some flats you should get an even better end result.

4 hours ago, Adreneline said:

The vast majority it would seem have to cope with some level of light gradient - I have an airport to the East - a town to the west - a city to the north and my own house to the west - I wonder sometimes why I bother!

Wow, challenging conditions! I have some mixed light pollution and find there's always some sort of substantial gradient to remove.  Thankfully it does generally get rid of the worst of it.  Pointing to different areas of sky and altitude obviously have diffing impacts.