My very second attempt!

[JonH]

After another night of imaging here is my result of M101
Didn't have a lot of time as have to get up at silly o'clock, 8x5min subs and 800iso stacked with dark frames in deep sky stacker.
Managed to get the guide camera working fine this time, 50mm extension did the job perfect!
Not sure but thing something wasn't right, all of the subs were pretty much a white out and after stacking could barely see this hiding in the middle it was all so 'cloudy' and white. Is this normal?
I cropped it to this bit then messed with the levels till it appeared, don't really have a clue what I'm doing with those though!

[Carole]

Well done John, that's a really faint target, and your stars are nice and round, so guiding worked well.

One thing I did forget to tell you which really depends on your location, is that if you have light pollution where you live you'll need a CLS LP filter.  The easiest thing for a DSLR is a clip in one.  Once you have that in place as well your subs will come our a light purple colour as in the image below.  This is the only one I could find ready to post, but this one also demonstates that will happen if you forget to remove your Bahtinov mask.  But it will do for showing you the colour of one sub.  Lurking in this image is the Horsehead nebula.


The other thing to bear in mind is the Moon will wash out the skies, which is why we go to Astro camp near a new Moon.  It is also not a good time for imaging (or observing) for the same reason, but it is certanly good for practice.  

Only exception to this is narrowband imaging which I am just getting into.

POst-processing is something you will learn gradually picking up a tip here and a tip there.  What software are you using to post-process?  Most people use Photoshop, or Pixinsight.  

Incidentlly Nik Szymanek will be the speaker at the next meeting who is an excellent imager and post-processor, make sure you don't miss it.

Carole

Carole

[JonH]

I didn't use anything to post process, just messed with the levels in deep sky stacker till I could see it.
At first I thought had messed up the alignment and missed it or just wasn't there but was just by chance I caught a glimpse of the laptop screen at a funny angle and could see a really faint tiny swirl bang in the middle!

Looks like I might have to get a CLS filter then, that said though it was pretty dark and other than the moon very little light about. Looking at the individual subs you can't even see a few stars, just a page of white! Even with bad light pollution that can't be right surely?!

[Rocket Pooch]

Incidentlly Nik Szymanek will be the speaker at the next meeting who is an excellent imager and post-processor, make sure you don't miss it.

Carole

Carole

I didn't know Nik worked at a sorting office?

Chris

Chirs

[Mac]

he is also an excellent train driver as well.

Mac

Mac

Mac.

[The Thing]

And last night there was a lot of high moisture in the air reflecting the moonlight, street light etc. It will be better tonight!

[JonH]

There was a quite a lot of 'glow' around the moon so I did wonder if that wasn't helping. But still, I can't help but think something isn't right here. Looking at my individual subs they not as bad as I first thought. But after stacking it's just rubbish!



This is one of the 5min subs



And this is after stacking





Am I doing something wrong here?

[Carole]

The first image is orange due to light pollution.  Faint objects will often not show up on a single sub, but will afetr stacking and processing (stretching etc).

The 2nd image is fairly normal for DSS, the images often come out washed out, all comes right once you process them.  Have you got photoshop Jon, that was something I forgot to put on your shopping list.  If not you can sometimes pick up cheap PS on Ebay. 

Carole

[JonH]

Ahh ok, I little more promising than I thought then.
I have got Photoshop somewhere, will have to dig it out and install it, will process it properly and see what I get.
Also found a clip in CLS filter going second hand so that's on it's way to me now

Another question though, when I save  the stacked imagine in DSS which format is best as are a few to choose from?

[mickw]

Can't remember the options but TIFF seems favourite but try to match what your version of PS can handle, not much good saving 32 bit when your version of PS can only handle 16 bit.

There is an alternative to PS that's free and will handle anything you throw at it and is very good - Iris -  it needs patience and a lot of learning and goes right over my head 

[Carole]

Yes, agree with Mick, make sure you save in Tiff and process in 16 bit, and save and keep in 16bit.  Only ever change your image into 8 bit and Jpeg format when you want to E Mail it or post it somewhere that won't take anything larger.

You will find over time as your processing skills improve you may want to go back and reprocess images, so also keep you original stacked file in unprocessed format.

To start with in Photoshop, play around with levels and Curves and see what you can achieve.
Watch the histogram and don't pull the sliders in levels past the histogram.  Curves is a poweerful tool and you can manipulate different levels of brightness independently.

Carole

[JonH]

I might have a go at some proper processing in a min, found some basic guides and info so going to see what i can do.
Got it imaging the Iris nebula right now, I'm really quite limited at what i can point the scope at between the trees, wanted to have another shot at M101 but by about half 11 i cant see it any more and wanted something i could get some good time on.
Plus i seem to be one of few not having trouble alingning/tracking tonight, the graph in PHD is coming out quite good! I think.......