New Setup - first guided M42

[StevieDvd]

Have a new setup comprised of the ZWO AM5, AsiAir Plus, ASI585MC, ASI120MM and William Optic Z61 with flattener & ZWO Eaf. So as you can imagine I need to get to grips with all the new gear, especially as this is my first real go at guiding & proper auto-focusing.

PA was was a breeze, and platesolving just worked first time. Guide settings took a little while to sort and will need some tuning, so I started with a target I'd not been able to get when I was working. M42 was always past my garden view point when I setup after getting home from work.

Below is a 60s x 10 capture processed in ASI Studio and only using auto stretch.

Update: Still learning the post processing but happier with this as a start. Need to cater for the over exposed core and improve black background a bit more I think.

And after trying to learn post processing with far too many software tools.

I tried to do some longer exposures of 180s & 300s but they seem over exposed and I believe I need to learn how to manage the gain settings with longer exposures. Silly me, thought that the AsiAir handled that as the camera set the gain at 252 (HGC some sort of a High Gain setting).

From a few videos on youtube it's been said that a lot of detail cannot be seen until it's post processed. Attached is a single fit image and the set of 10. If anyone wants to see if there is data to pull out and improve the image over the basic AsiDeepStack I'd be pleased to learn what to look out for.

Any tips on working out suitable settings on the AsiAir gear for longer exposures would be welcome too.

Thanks

Steve

 

m42_60s_asi585mc.fitm42_60s_asi585mc.zip

Edited January 1, 2023 by StevieDvd
Another processed image added.

[Adreneline]

Hi Steve.

I've had a very quick go at the .fit file and once the background gradient is removed and a little tweak with colour calibration quite a lot more detail is revealed and a nicely aligned histogram.

I am not at all familiar with the 585 but generally I would say stick to one gain setting and vary the exposure.

M42 is a very bright target and I've used exposures as short as 15s in the past; 180s and above would seem excessive to me.

I've not used ASIStudio so cannot offer any advice on that one, but I do use an ASIair and love it!

HTH

Adrian

 

 

Edited December 10, 2022 by Adreneline

[ONIKKINEN]

Looking at the specs of the sensor:

Looks like 252 is the right gain to use since it has the obvious read noise advantage to anything lower than that. But not worth it to go higher than that with the diminishing returns.

Hard to say from the graphs but the "dynamic range close to 12-bit" part of the description seems to suggest that the full-well capacity is somewhere around 4ke-. In non technie real world speech that means you may want to keep exposures closer to the minimum viable length rather than go up to 3 or 5 minutes.

Looking at your 60s exposure it looks like that is already long enough/too long. But star saturation might be something you just have to accept if you dont want to take very short exposures only and have a mountain of them in the end and if you want to get unsaturated stars you could shoot another short stack of say 10 second subs where stars are not saturated and use that as a star layer in processing. That takes some layering and masking magic in PS/Gimp to happen but might be worth it if the saturated stars bother you.

[vlaiv]

Interestingly enough - flats would help as well.

Although it is small sensor - there appears to be some level of vignetting as well.

[StevieDvd]

1 hour ago, Adreneline said:

Hi Steve.

I've had a very quick go at the .fit file and once the background gradient is removed and a little tweak with colour calibration quite a lot more detail is revealed and a nicely aligned histogram.

I am not at all familiar with the 585 but generally I would say stick to one gain setting and vary the exposure.

M42 is a very bright target and I've used exposures as short as 15s in the past; 180s and above would seem excessive to me.

I've not used ASIStudio so cannot offer any advice on that one, but I do use an ASIair and love it!

HTH

Adrian

 

 

Thanks Adrian, the move to a proper guided image and improved cameras (and the plethora of images posted with long exposures by others) led me to think that longer was now the norm. But the above image is a lot better than I thought it would be (processed properly) 😁 Will be doing dark & flats for later session, now I have a cheap light panel which arrived today.

What's the software used in your post that produced the magic? I only use ASIStudio as a tool for setting focus on cameras etc and for Solar imaging.

I have Photoshop (old version) as I used to do image editing/renovating old images from the 1940's for my parents . So on the todo list is to check out the latest ;user friendly; stacking/astro tweaking software.

 

1 hour ago, ONIKKINEN said:

Looking at the specs of the sensor:

Looks like 252 is the right gain to use since it has the obvious read noise advantage to anything lower than that. But not worth it to go higher than that with the diminishing returns.

Hard to say from the graphs but the "dynamic range close to 12-bit" part of the description seems to suggest that the full-well capacity is somewhere around 4ke-. In non technie real world speech that means you may want to keep exposures closer to the minimum viable length rather than go up to 3 or 5 minutes.

Looking at your 60s exposure it looks like that is already long enough/too long. But star saturation might be something you just have to accept if you dont want to take very short exposures only and have a mountain of them in the end and if you want to get unsaturated stars you could shoot another short stack of say 10 second subs where stars are not saturated and use that as a star layer in processing. That takes some layering and masking magic in PS/Gimp to happen but might be worth it if the saturated stars bother you.

That's good to know - otherwise I'd be wating time trying out loads of gain values and exposure times to fathom out what to use. I appreciate it would differ with M42 as that's a notorious one for too bright in one place, too dark in others, but I have layered in PS before so will try that after improving data by taking darks/flats and a decent stack/histogram.

 

1 hour ago, vlaiv said:

Interestingly enough - flats would help as well.

Although it is small sensor - there appears to be some level of vignetting as well.

Darks & Flats are to be done in future sessions so better data to come I hope.  Had not noticed any vignetting, I wonder if that's down to the camera or the WO Flat61A (only set to the listed specs which may need to be afjusted or I got plain wrong).

@Adreneline, @ONIKKINEN & @vlaiv - your comments and help are much appreciated and will be taken on board so I'll be able to post some images that won't be too embarrassing.

Regards

Steve

 

 

[StevieDvd]

BTW,

As the setup is mostly new to me I spent more time getting the hang of the parts of Asiair I'd not used before.  I spent too much time trying to rotate the image capture area before calling it a night, only to remember later the scope has a rotate option on the flattener, doh!

[Adreneline]

19 minutes ago, StevieDvd said:

What's the software used in your post that produced the magic?

Hello Steve. No magic I'm afraid 🙂 - and nothing "embarrassing" about your image. (you want to see some my early attempts 🤪)

I used AstroPixelProcessor to remove the background gradient(s); APP is also my software of choice for all pre-processing.

I used PixInsight to process the image. It has a reputation for being user unfriendly but in my opinion it is no different to PS - you have to get used to it and the way it works and does things.

I am very much of the view that PI is worth every (one off) penny and represents a small percentage of what I've spent on hardware over the years; it lets me get everything there is to get from my hard earned data.

PS is part of Adobe's Creative Suite - PI is anything but "creative". Okay - I lit the blue touch paper! 🤣

 

Edited December 10, 2022 by Adreneline
Clarification

[StevieDvd]

@Adreneline

Thanks, I'll check out APP first to see how I fare.  I am okay with paying for software that I'll use 🙂

[knobby]

Might be worth trying Siril, it's free and in some ways similar to Pixinsight.

https://siril.org/

Very nice M42 👍🏻

[Elp]

I've had a go (great camera, I use its predecessor the 485mc for DSO), would of been great with flats applied, tried my own. My usual blotchy painterly look. Processed via Siril, GIMP and PS:

[alacant]

21 hours ago, StevieDvd said:

they seem over exposed

Hi

Lovely shot. You have captured detail right into the difficult bright bits. 

Beats anything I've seen over 60s.

Cheers

[StevieDvd]

56 minutes ago, alacant said:

Hi

Lovely shot. You have captured detail right into the difficult bright bits. 

Beats anything I've seen over 60s.

Cheers

Guess I must have had a 'lucky imaging' night without realising it.

At the time I was pleased with the raw images being better than my past sessions but had no idea that the details you people could pull out were even present.

The phrase 'I am literally blown away' by the above posters processing of my capture may be grammatically incorrect but it matches my feelings.

Thanks all, am now learning how to process in earnest and consuming youtube videos on the various software. Siril does seem to be one I can understand the easiest so far, and the PS processing is within my grasp having done non-astro in it before.

Regards

Steve