help with processing please :)

[Andywilliams]

i have been mildly successful with my new barn door tracker but when i attempt to process in Gimp and try to tease out details i seem to just create a snowstorm!  ithe first image is a short stack of pics of M31 but i am sure more of the galaxy could be gotten from the TIFF? and the second is obviously Orion, again its short on times....maybe 10 minutes in total stacked in deep sky stacker (canon 1000D 50mm stock lens at 30mm).....could anyone get the best from these images?....any help and advice would be most gratefully welcomed.

 

andromeda.tif

orion barndoor.tif

[D4N]

What version of Gimp are you using?

It needs to be at least 2.9 to be able to process in 32bits, if you process in 16bits then you will lose data when you stretch as there is nowhere for it to go.

[happy-kat]

Great you made your own barn door tracker.

Had a quick process in paint shop pro levels and curves.

Firstly you would need to crop the image to remove the edge artifacts from stacking. Also there is a fair amount of star trailing and focus is really important to get as good as you can manage. If you have an android phone/tablet then dslr controller is an excellent application to work with a canon camera to both cobtrol it and help with focus. Looks like your histogram was in a good place.

Roll on the next clear night so you can use your barn door.

[happy-kat]

I am afraid I can't do anything with the other image.

Flats would help with the vinyetting (the darkening in the corners) and I use an app called lighbox on my android table to take these.

If you use your lens at the widest setting that in theory buys 22 seconds of exposure before star trails show, so using that focal length you could practice getting nice long exposures with such a margin of padding built in. This will help you know if you are getting your polar alignment good enough when you set your barn door up. Also the one revolution per minute is only true if the distance from the hinge to the bolt is correct for the bolt size and thread pitch.

link to calculating

Lastly you could use your go to mount just with your DSLR and image, you will get ebtween 20-45 second length exposures depending where in the sky you look, see the no eq challenge thread.

[Andywilliams]

Hi happy-Kat.....many thanks for your suggestions......my polar alignment was probably a little off as I am using a laser pointer to get as close as possible which can be tricky in the Southern Hemisphere as there is no Polaris to point at! ....also, I didn't mention in my post but it was very windy but my only chance in a recently continuous overcast sky, to get out into it. I am still trying to get the hang of perfect focus !.....onwards and upwards !! .....cheers, Andy 

[Andywilliams]

Also, in deep sky stacker it only seems to be choosing one or two of my images  ?? could this be due to the images being of different timing lengths? 

[Andywilliams]

Hi Dan, many thanks for the tip.....I have version 2.8 so I'm guessing that I'm wasting my time with it.....I will get the latest version I can find......unfortunately I can't afford the light box rent or anything fancy like pixnsite, unless you can suggest a freebie that is useful for astrophotos?....cheers, Andy 

[D4N]

 

28 minutes ago, Andywilliams said:

Hi Dan, many thanks for the tip.....I have version 2.8 so I'm guessing that I'm wasting my time with it.....I will get the latest version I can find......unfortunately I can't afford the light box rent or anything fancy like pixnsite, unless you can suggest a freebie that is useful for astrophotos?....cheers, Andy 

Gimp 2.9 should suffice for what you are doing I think, it has good levels and curves and you can use layers so you can d a lot with it.

 

I was wondering why Orion was upside down then I saw where you are and it makes sense

 

32 minutes ago, Andywilliams said:

Also, in deep sky stacker it only seems to be choosing one or two of my images  ?? could this be due to the images being of different timing lengths? 

You can force DSS to stack images of different exposure lengths (I think in the file list), although it is better to get them the same length.

[Andywilliams]

Thanks Dan, I will keep on experimenting and hopefully improving !

[wornish]

First your barn door mount is very impressive.

As you said in your original post the total exposure time is very short in both images and that is the one thing that will make a big difference.

You need to try and get at least 30 min  total time  ( 30 x 1min,  or 60 x 30sec shots) or even an hours worth of shots to really start bringing out the galaxy in the M31 shot,  it is there but is also very small using a 30mm lens.  You also got some passing clouds  in the shot which dont help.

Here is a stretched version of your M31, think its just visible on left side about a third of the way up.  I tried cropping  around it to see if more info is there but it doesn't seem to make much difference.

 

The Orion shot is the same needs more stacked images.

 

 

[Andywilliams]

Many thanks Dave, I am re looking at the deep sky stacker.....because the images were of slightly varying lengths I think DSS packed a sad and gave me a stack of one! .....I will try to force it to stack the different length images and see if it gives me more info....cheers for the tips, Andy 

[happy-kat]

You can stack different lengths just use the tabs along the bottom for the separate sets. If it won't stack the star trails are too big I think.