First Nebula (anything really) captured now I’m hooked !

[Newforestgimp]

Processed my first ever tracked image, I chose two targets as a bit restricted from my garden. Crescent Nebula and Orion Nebula, Orion Nebula came out ok but I need some pointers on basics of gimp, sone foolproof tutorials etc ? As I just can’t bring out much at all of the Crescent Neb, extremely faint from my 105 45second images using WO z61, DSLR, eqm-35

[fifeskies]

Try these 2 , I found them very good

GIMP Astrophotography Editing Tutorial - YouTube

DeepSkyStacker and GIMP - How to capture a galaxy with your DSLR, Part 2A - YouTube

 

[Newforestgimp]

1 hour ago, fifeskies said:

Try these 2 , I found them very good

GIMP Astrophotography Editing Tutorial - YouTube

DeepSkyStacker and GIMP - How to capture a galaxy with your DSLR, Part 2A - YouTube

 

Cheers, I’ll take a look 👍

[fifeskies]

45 second subs are not that long for the fainter DSO , but if you are tracking without guiding you may be limited in exposure time before you get some trailing.

As you found it is fine for the likes of the bright Orion Nebula , the fainter objects will be easier if you can run longer exposures

 

 

Orion Nebula is about Mag +4

Crescent is about         Mag +7.4

This is a lot less bright , the mag scale is logarithmic , each step being approx x 2.5 (so 3 mag is 15.5 times)

 

A 3.4 mag difference means it is about 20 times fainter 

 

In general I use guided subs of 180 seconds to 360 seconds and stack about 60 to 120 images for objects that faint , though it does vary by target.

 

That all said GIMP when used in the way the tutorials show you is pretty good at extracting even very low data from frames that look at first to have almost no content. 

 

 

 

 

 

 

 

Edited December 27, 2020 by fifeskies

[Newforestgimp]

On 27/12/2020 at 10:55, fifeskies said:

45 second subs are not that long for the fainter DSO , but if you are tracking without guiding you may be limited in exposure time before you get some trailing.

As you found it is fine for the likes of the bright Orion Nebula , the fainter objects will be easier if you can run longer exposures

 

 

Orion Nebula is about Mag +4

Crescent is about         Mag +7.4

This is a lot less bright , the mag scale is logarithmic , each step being approx x 2.5 (so 3 mag is 15.5 times)

 

A 3.4 mag difference means it is about 20 times fainter 

 

In general I use guided subs of 180 seconds to 360 seconds and stack about 60 to 120 images for objects that faint , though it does vary by target.

 

That all said GIMP when used in the way the tutorials show you is pretty good at extracting even very low data from frames that look at first to have almost no content. 

 

 

 

 

 

 

 

Thanks for the guidance, I did wonder how the Mag scale worked, makes sense now.

As this was my first outing, first polar alignment, first mount/scope alignment  I thought I would stay conservative on the exposure duration.

I can just about make out the Crescent Neb when adjusting with GIMP & tbh I’m still pleased just the fact that I managed to get it in the frame at all as it was a finger in the air uneducated guess !

I will try pushing the exposure a bit more on next attempt. It’s a bit tricky trying to find suitable targets, from my garden I only have a limited sky window, generally SOUTH SOUTH/WEST & NORT WEST, the rest is obscured by houses etc.

steep learning curve but that will make it more satisfying when/if I nail one 😉

[fifeskies]

You should give Andromeda M31 a go

Its very high just now so you should find it easily to the South (later evening) at a high elevation

Nice bright target compared to the Crescent and always a thrill as it pops out of the background when image is stretched (in eg GIMP)

Compared to what you see visually even short exposures stacked have a "wow" factor

[Newforestgimp]

6 minutes ago, fifeskies said:

You should give Andromeda M31 a go

Its very high just now so you should find it easily to the South (later evening) at a high elevation

Nice bright target compared to the Crescent and always a thrill as it pops out of the background when image is stretched (in eg GIMP)

Compared to what you see visually even short exposures stacked have a "wow" factor

It’s top of my list actually when I realised I might just be able to reach it currently, keeping everything crossed for a clear window in the coming days 👍

Any other suggestions gratefully received, need to focus (excuse the pun) on targets that reveal if I’m doing the right things.

[fifeskies]

I actually have a similar horizon to yourself blocked by trees from South East to North 

M31 being so high will be moving relatively slow across the sky so you can push the exposure time on it.

 

 

Deep Sky Objects by Magnitude for Inverness tonight (telescopius.com) 

this site will keep you up to speed on the best targets each day , just input your own co-ordinates for best functionality.

Look for objects transiting south at times you can get out imaging.

 

Also give the North America Nebula a try , its better in an astromodified camera (being an Ha emmision nebula) but should still work if you stack a good few exposures, high up to south west just now mid evening.

[Osiris777]

On 26/12/2020 at 18:13, Newforestgimp said:

Processed my first ever tracked image, I chose two targets as a bit restricted from my garden. Crescent Nebula and Orion Nebula, Orion Nebula came out ok but I need some pointers on basics of gimp, sone foolproof tutorials etc ? As I just can’t bring out much at all of the Crescent Neb, extremely faint from my 105 45second images using WO z61, DSLR, eqm-35

Isn't it such a great feeling capturing your first target!?  I would say, after viewing a lot of folks images on here and on astro bin, getting proper framing is almost as important as the target itself (I have a tendency to overcrop and zoom too far in for my final image, losing perspective and resolution).  With the 61, I'd think you'd be able to have a great field of view with the nebula at center and a nice wide border.  Just my .02c, and great job getting your first image!!

[nephilim]

I'd have a look at starting to try & get some calibration frames as well. Dark frames will help get rid of the noise associated with DSLR's, all cameras suffer from it but with DSLR's its a bigger issue. Unfortunately calibration frames are a necessary evil & will help improve future images.
Well done on your first one though 🙂

If your unsure about taking calibration frames there's a lot of tutorials on YouTube etc. This will give you a brief idea to start with though. https://practicalastrophotography.com/a-brief-guide-to-calibration-frames/ 

[michael.h.f.wilkinson]

The Crescent is doable with short exposures, but much depends on sky quality. I have managed to get decent results with a load of 30s exposures, but with a rather larger scope (Meade SN6 6" F/5 Schmidt-Newton), more sensitive chip (using an ASI183MC camera) and an Optolong L-eNhance filter to suppress sky background. This is a total of 3 h 40 min 30 sec exposure 

[Newforestgimp]

7 hours ago, Osiris777 said:

Isn't it such a great feeling capturing your first target!?  I would say, after viewing a lot of folks images on here and on astro bin, getting proper framing is almost as important as the target itself (I have a tendency to overcrop and zoom too far in for my final image, losing perspective and resolution).  With the 61, I'd think you'd be able to have a great field of view with the nebula at center and a nice wide border.  Just my .02c, and great job getting your first image!!

Yea the framing was an issue, I was actually packing up when I turned and saw Orion’s Belt was now visible from my garden so I hastily slewed to the nebula and fired off a quick 30 exposures whilst putting stuff away and as it turned out the nebula was right at the edge of the frame so some of the stars have suffered (no flattener).

I have a horrible feeling a dedicated Astro cam will start making sense 🙈

[Newforestgimp]

5 hours ago, michael.h.f.wilkinson said:

The Crescent is doable with short exposures, but much depends on sky quality. I have managed to get decent results with a load of 30s exposures, but with a rather larger scope (Meade SN6 6" F/5 Schmidt-Newton), more sensitive chip (using an ASI183MC camera) and an Optolong L-eNhance filter to suppress sky background. This is a total of 3 h 40 min 30 sec exposure 

Lovely shot ! Think I made schoolboy error in choosing this as the first subject, I will stick to bigger and brighter for a while before returning to it.

[Newforestgimp]

6 hours ago, nephilim said:

I'd have a look at starting to try & get some calibration frames as well. Dark frames will help get rid of the noise associated with DSLR's, all cameras suffer from it but with DSLR's its a bigger issue. Unfortunately calibration frames are a necessary evil & will help improve future images.
Well done on your first one though 🙂

If your unsure about taking calibration frames there's a lot of tutorials on YouTube etc. This will give you a brief idea to start with though. https://practicalastrophotography.com/a-brief-guide-to-calibration-frames/ 

Yeah I only took 10 Darks, I intended to take some BIAS frames too but got distracted when I noticed Orion had moved into view 🙈

need to suss a way of doing the FLATS without too much effort.

[michael.h.f.wilkinson]

1 minute ago, Newforestgimp said:

Lovely shot ! Think I made schoolboy error in choosing this as the first subject, I will stick to bigger and brighter for a while before returning to it.

Your scope should be able to catch it, (I have spotted it wide-field shots of the Sadr region using a short telephoto), but it will need dark skies, or a filter to suppress the sky background

[fifeskies]

17 minutes ago, Newforestgimp said:

 Think I made schoolboy error in choosing this as the first subject, I will stick to bigger and brighter for a while before returning to it.

There are plenty good bigger brighter targets that can keep you going for a full winter, and a DSLR is no poor option either , the nice big sensor will allow you to capture some impressive big nebula.

Enable the nebula (DSO) display in Stellarium to highlight them for you

 

 

 

 

 

Edited December 29, 2020 by fifeskies

[nephilim]

20 hours ago, Newforestgimp said:

Yeah I only took 10 Darks, I intended to take some BIAS frames too but got distracted when I noticed Orion had moved into view 🙈

need to suss a way of doing the FLATS without too much effort.

Ah, you'll know then that flats are a pain  The scope has to stay in exactly the same position (orientation) as when you took the light frames, same focus & same ISO which is easier said than done. A white T shirt folded double & then placed  tight over the end of the scope, I used a tablet with the white screen & aim for the histogram to be as central as you can get it. The reason for doubling the T shirt is that with the tablet method am unfolded T shirt wont work as its too bright.
I'm just getting back into AP after a long break from it due to sub optimal kit the first time around. I always used the T shirt method but its been a long time since I've last done any but I'll be using this method this time around. This has some great info/ advice https://astrobackyard.com/how-to-take-flat-frames/

Edited December 30, 2020 by nephilim

[michael.h.f.wilkinson]

Same ISO or exposure is not necessary for flats. Just take dark flats at same ISO and exposure as the flats and you will be fine. Flat panels are the easiest way to get flats. 

[Newforestgimp]

I’ve literally just tried the method that astrobackyard recommends, t-shirt over scope pointing at the morning sky, camera set to AV. There seemed to be a worrying strip of darkness across the top of the frame ?

[fifeskies]

Might be a fold in the material or a seam.

Just try again and make sure the material over the lens is nice and even.

(Was it a cloudy sky , a clear sky isn't really as suitable ,  a uniform even grey high cloud is best to avoid gradients)

 

I use an acrylic sheet to do mine , opal colour and fits on with 2 screws like a bahtinov mask , it just hangs on the Dew shield at the front

Cost me a few £ on auction site and I find it easier than the t shirt method , keep it handy in a padded envelope to avoid scratches and dust,

 

 

Edited December 30, 2020 by fifeskies

[Newforestgimp]

Yet another good idea 💡 Thank you

[gaz81]

Nice! 
 

It’s such a good feeling when you pop your space cheery. Haha. 
 

I was the same but with Neowise and Andromeda. 
 

After that... totally hooked! ...and love playing with the gear also.  

Some really good stuff on YouTube from the likes of ‘Cuiv The Lazy Geek’ , ‘Astrobackyard’ etc... also like ‘Dylan O’Donnell’ but he is pretty sarcastic, which I like. 

[Newforestgimp]

12 hours ago, gaz81 said:

Nice! 
 

It’s such a good feeling when you pop your space cheery. Haha. 
 

I was the same but with Neowise and Andromeda. 
 

After that... totally hooked! ...and love playing with the gear also.  

Some really good stuff on YouTube from the likes of ‘Cuiv The Lazy Geek’ , ‘Astrobackyard’ etc... also like ‘Dylan O’Donnell’ but he is pretty sarcastic, which I like. 

I do like watching the Astrobiscuit guy as it’s more realistic, but would love to know how he’s getting free OTAs !!!

finding GIMP a bit tricky to use, every layer looks the same 😂 

[fifeskies]

When I started with GIMP I ran the tutorial in a small window pressing play and pause with each step I copied.

After a while it gets more familiar.

 

GIMP Astrophotography Editing Tutorial - YouTube

 

 

[Newforestgimp]

Yes I watched it and made notes, a step by step set of instructions but I get lost around creating the star masks etc, I’ll try like you say play/pause whilst editing alongside. Also the quality of the data he is using is better than I’ve captured so there’s a lot more signal to play with.

I tried with the 30mins of andromeda I captured in a cloud window, although not the greatest the process is becoming a bit more natural...