My First Attempt at Imaging M81 + M82 with 130P DS

[acharris77]

Hi all, attached is my first attempt at imaging with the 130P DS. I am using a Syncscan Alt/Az mount, so I was limited to 25 Second exposures. And also I need to purchase a light pollution filter or Baader Neodyium (sp?) filter in 2" as I only have a 1.25" one, so pollution was a slight issue.

I decided to try the M81 and M82 galaxies for a first attempt. So I took 20 x 25 sec subs and took 10 darks at the time and stacked in DSS and then edited in PS. For a first go on a alt/az mount I am quite happy to have captured both. I am looking to get a EQ5 pro so I can track longer than 25 secs and would have like to have had more subs looking at the image.

I am guessing the noise or gradient is caused by amp glow or something else, as I am relativity new to imaging DSO with DSLR. My camera is a 1000D. WIth the flaws I am still happy with the focus and detail I managed to get.

Thanks for viewing and any advice is appreciated.

[JemC]

Well done you on your 1st attempt, that's a pretty impressive capture.

I've just recently acquired one of those scopes but have yet to put it to good use.

Regards

[acharris77]

Thought I would have another play with the processing of the M81 and M82, and this is my 2nd attempt to see if I could get rid of the Light Pollution to the left of M81. Can I have opinions please

Thanks.

[toxic]

well done indeed welcome to the darkside

[faulksy]

lovely, and great location, thats how i see it through my dob

[KJ Dalley]

Thought I would have another play with the processing of the M81 and M82, and this is my 2nd attempt to see if I could get rid of the Light Pollution to the left of M81. Can I have opinions please

Thanks.

If I may ask a question that probably sounds dumb to the massive talents on this forum, but how on earth did you get rid of the Light Pollution?

I'm using the older Canon 450D and I've had some good shots but I tried a similar shot to yours a few nights agoa with M81 & M82, using 100 x subs at 15 secs at ISO 400. I've got data obviously but no matter what I do with it, it looks noisy. Do you use the 2d Drizzle options in DSS? My laptop needs a memory upgrade before I can explore that option and I need to develop some photo editing skills so any pointers would also be welcomed!

Clear skies.

[NGC 666]

Assuming you have Photoshop, or software which can use levels/histogram/curves, you can use the set black point on the levels tool on the light pollution, which sets the black point of the image to be the level colour of light pollution.

(NGC 6946 without black point set to light pollution)

(NGC 6946 with black point set to light pollution)

You have to be careful not to remove precious data of the object you're imaging, and may have to correct the white balance afterwards.

Sliding the black point slider on the histogram (in levels in Photoshop) can also do a similar job, just less precise.

These are two of many ways of doing it, I'm sure - it's just the method I use. I'm also confident other software supports this, too. Just not DSS, unfortunately (I don't process anything in DSS after stacking).

[NGC 666]

Correction!

 set black point (eyedropper) on the levels tool on the light pollution, which sets the black point  of the image to be the level/colour of light pollution.