First attempt Orion Nebula M42

[Adam1234]

I had a go at the Orion Nebula last week. Quite happy with the result considering it's only a stack of 7 x 30s images at ISO 1600, with 20 x bias and 30 x darks. Taken with Canon 2000D through Sky-Watcher 10inch Dobsonian on alt-az mount.

 

Also took some images of the M38 Starfish Cluster?  (20 x 5s images at ISO 3200, 10 x darks)

 

 

Adam

[Adam1234]

Took some 135 x 30s images of Andromeda as well, but this is the best I seem to be able to get out of the stacked image. I've spent a bit of time trying to edit in Photoshop but finding it difficult to bring the fainter bits out, maybe it's not possible considering the light pollution from the streets lamps in my area.

 

[Benjam]

14 minutes ago, Adam1234 said:

Took some 135 x 30s images of Andromeda as well, but this is the best I seem to be able to get out of the stacked image. I've spent a bit of time trying to edit in Photoshop but finding it difficult to bring the fainter bits out, maybe it's not possible considering the light pollution from the streets lamps in my area.

 

Hi Adam, this was my Andromeda attempt. I piggybacked my cannon 1300d and took one unguided 90 second exposure at 800 iso and @ 200mm.

I do like you’re Orion nebula image, well done. 

Ben 

Edited December 6, 2019 by Benjam

[Adam1234]

5 minutes ago, Benjam said:

Hi Adam, this was my Andromeda attempt. I piggybacked my cannon 1300d and took one unguided 90 second exposure at 800 iso and @ 200mm.

I do like you’re Orion nebula image, well done. 

Ben 

That's a nice one

[rickwayne]

Thirty seconds might be a little shy on sub-exposure time, but over an hour of total integration time should be sufficient to bring out a lot more detail, even in fairly light-polluted skies.

Do you happen to recall what the histogram looked like for any of your sub-exposures, or can you re-summon it? If the big peak from the sky background (gazillions of pixels that represent "black" -- ha ha! -- sky) is something like 1/3 of the way along from the left edge, you should be able to dredge more out of your data.

I get that you can't go much longer on sub time with an alt-az mount -- you're just edging into eggy-star territory, there -- but you may be able to crank up the data you've already got.

If you're using Photoshop, you can give Mark Shelley's arcsinh curves a whirl, they do a nice initial "stretch" for you that should be in the ballpark.

This image is not a brag, there are so many things "off" with it that I almost hesitate to post a link. (Stars that are little arrowheads! Blue where blue Should Not Be! Etc., etc.) Nevertheless, it's got a lot of detail in the galaxy. The total integration time was less than yours, 19 x 129 seconds at ISO 1600, if memory serves, and I shot it with a stupid-slow mirror lens. Skies were maybe Bortle 5 (dark yellow on a light-pollution map).

M31 with Tamron 500mm f/8 lens, 19 x 129s

Edited December 6, 2019 by rickwayne

[Adam1234]

On 06/12/2019 at 18:08, rickwayne said:

Thirty seconds might be a little shy on sub-exposure time, but over an hour of total integration time should be sufficient to bring out a lot more detail, even in fairly light-polluted skies.

Do you happen to recall what the histogram looked like for any of your sub-exposures, or can you re-summon it? If the big peak from the sky background (gazillions of pixels that represent "black" -- ha ha! -- sky) is something like 1/3 of the way along from the left edge, you should be able to dredge more out of your data.

I get that you can't go much longer on sub time with an alt-az mount -- you're just edging into eggy-star territory, there -- but you may be able to crank up the data you've already got.

If you're using Photoshop, you can give Mark Shelley's arcsinh curves a whirl, they do a nice initial "stretch" for you that should be in the ballpark.

This image is not a brag, there are so many things "off" with it that I almost hesitate to post a link. (Stars that are little arrowheads! Blue where blue Should Not Be! Etc., etc.) Nevertheless, it's got a lot of detail in the galaxy. The total integration time was less than yours, 19 x 129 seconds at ISO 1600, if memory serves, and I shot it with a stupid-slow mirror lens. Skies were maybe Bortle 5 (dark yellow on a light-pollution map).

M31 with Tamron 500mm f/8 lens, 19 x 129s

So this is one of my subs:

IMG_1216.dng

And this is the sub opened in photoshop so you can see the histogram:

 

 

It won't let me upload the stacked tiff image for some reason?, but this is screenshot in photoshop with the histogram:

 

I've had many attempts at trying to stretch the histogram using YouTube tutorials with limited success, the original image I posted seemed to be the best I could do. With my limited knowledge and beginners status, I had come to the conclusion that any data in the fainter parts of the galaxy outside of the core is just too close in brightness to the background to bring out any detail without also brightening up the background. I could obviously be wrong!

Adam 

 

 

 

 

[rickwayne]

I did not spend a lot of time on it, but I did apply an arcsinh300 and an arcsinh10 stretch to your single sub and I gotta admit...I couldn't get it going on either. Nor could I get much when I wonked on it manually. Strange. I still maintain that it ought to work... 🙂

 

[Adam1234]

4 hours ago, rickwayne said:

 Strange. I still maintain that it ought to work... 🙂

 

My thoughts exactly, hence why I posted on here to see if anyone else could wrangle the data out. 

Perhaps I'll concentrate on some of the brighter nebulae and star clusters for the time being until I can get  out to a dark sky and/or have the capability to do >30s subs without star trails i.e. get an Eq mount.  May be a while before I get an Eq as I've got a wedding to pay for, plus polaris is blocked by my flat so would be difficult to polar align from my garden anyway!

[rickwayne]

On 09/12/2019 at 03:17, Adam1234 said:

May be a while before I get an Eq as I've got a wedding to pay for, plus polaris is blocked by my flat so would be difficult to polar align from my garden anyway!

Oh come now, what bride or groom would prefer a nice wedding to a nice mount? ;-}

Actually, I know what mine would have said: "That's a really beautiful piece of equipment, sweetheart. Well done you! It will look lovely standing up at the altar with you."

In any case, congratulations, whether it's your own wedding you're paying for or an offspring's. I am all about this marriage thing.

If you find a way to upload your original M31 data someplace (Dropbox e.g.), if I have a few minutes I'll have a go at them with Astro Pixel Processor. 

Finally, don't let Invisible Polaris stop you. Pretty much all the EQ mounts you'd be looking at for astrophotography can use their sky model to iterate back and forth between other stars, allowing you to adjust the ALT and AZ until the polar axis is dialed in. Then you can do a drift check (a couple minutes, tops) to ensure that it's spot-on. More trouble than squinting through a polar scope, but eminently doable. One of the small advantages to living in light pollution is that your sub-exposures have to be shorter in the first place, so one needn't obsess over polar alignment.

[Adam1234]

6 hours ago, rickwayne said:

Oh come now, what bride or groom would prefer a nice wedding to a nice mount? ;-}

Actually, I know what mine would have said: "That's a really beautiful piece of equipment, sweetheart. Well done you! It will look lovely standing up at the altar with you."

In any case, congratulations, whether it's your own wedding you're paying for or an offspring's. I am all about this marriage thing.

If you find a way to upload your original M31 data someplace (Dropbox e.g.), if I have a few minutes I'll have a go at them with Astro Pixel Processor. 

Finally, don't let Invisible Polaris stop you. Pretty much all the EQ mounts you'd be looking at for astrophotography can use their sky model to iterate back and forth between other stars, allowing you to adjust the ALT and AZ until the polar axis is dialed in. Then you can do a drift check (a couple minutes, tops) to ensure that it's spot-on. More trouble than squinting through a polar scope, but eminently doable. One of the small advantages to living in light pollution is that your sub-exposures have to be shorter in the first place, so one needn't obsess over polar alignment.

It is indeed my own wedding,  I proposed while we were in Iceland!

I'll have a go at uploading the M31 data to dropbox tomorrow.

[Mark1489]

On 08/12/2019 at 12:07, Adam1234 said:

So this is one of my subs:

IMG_1216.dng 24.37 MB · 4 downloads

And this is the sub opened in photoshop so you can see the histogram:

 

 

Hi Adam! I really like your Orion Nebula, it looks very natural! I’ve noticed in your sub screenshot that it’s an 8 bit image, I’m not familiar with your camera but try shooting at 12 or 14bit if possible! That should capture greater detail per sub 😃

Edited December 13, 2019 by Mark1489

[Adam1234]

22 hours ago, Mark1489 said:

Hi Adam! I really like your Orion Nebula, it looks very natural! I’ve noticed in your sub screenshot that it’s an 8 bit image, I’m not familiar with your camera but try shooting at 12 or 14bit if possible! That should capture greater detail per sub 😃

Thanks Mark, glad you like it, I appreciate  the feedback! 

I save my stacked images in DSS as 16 bit, but I'll have a look on my canera and see if I can shoot at a higher bit.

 

Hopefully get round to putting the original m31 subs on dropbox tonight or tomorrow