Help with image processing (Horsehead)

[Stefannebula (Stefan)]

I'm relatively new to this amazing hobby, but I've produced some astrophotos I'm very happy with. This time however not so much.

Got 2 hours worth of exposure data on the Horsehead Nebula (72 100s exposures @ISO800). However there are too many photos for my computer to handle on photoshop, so I instead turned to DeepSky Stacker to stack the images. After importing the result to photoshop and processing my usual way the result was extremely underwhelming.

Not sure if my issue is with DSS or just my images, but I though 2h would be enough to get a bit more on this target.. Any words of wisdom would be much appreciated!!!

And the image looks this horribly stretched because it's the only way I could see any actual detain around the horsehead!

Equipment: Skywatcher BD ED100 on NEQ6, Unmodded Canon EOS 700D

[ZeroID (Brent)]

Just had a fiddle with the lo-res jpg ( not a great idea) but there seems to be a lot of red Light Pollution (?) saturating the background. What did the histogram look like when you were imaging ? I'm assuming you were using BYE or similar. In levels in PS2 the peak is well clear of the left side. An LP filter might help or a shorter exposure.

[Tony_ (Tony)]

G'day Stefan,

The horsehead isn't particularly easy with an unmodded dslr - the cameras filter cuts out most of the light in the Ha and Hb range.
When I am centering an object I turn the ISO up to 6400 and take 20 - 30 sec subs so I can see the object. In general if the object isn't easy to see in these subs then it isn't going to be a very good image with only 1-2 hours total exposure. I usually image at ISO 800 or 1600.
Try 120s subs at ISO 1600 and use a LP filter if you have one. It may be a bit noisy but it will give more to work with. I doubt whether you will get a great image with an unmodded camera though. My attempts were dismal. You will probably need a lot more than 2 hours.
If you don't use an LP filter it is possible that your camera is picking up more signal from light pollution than it is from the nebulosity so it will be very hard to get a good image.

Tony.

[raymo]

Hi Stefan, I think you must have done something wrong somewhere during the DSS phase of your imaging, because, whilst quality images of the Horsehead require at least a modded DSLR, passable newbie images
can be obtained with an unmodded one and short subs. I took the attached pic several years ago with 80mm achro 20x 30 secs @ 1600 ISO
and unmodded 1100D.
raymo

[VS6000 (Tim)]

In a dark sky spot in Tassie I was getting great in-camera visible images of horsehead with iso 3200, F3.2 and 30 seconds