Jump to content

NLCbanner2024.jpg.2478be509670e60c2d6efd04834b8b47.jpg

First DSO - M57 - I'm hooked!

Brent

By Brent
in Imaging - Deep Sky

Recommended Posts

Brent

Brent

Posted
Posted

Well, after a month of not being able to get the scope out due to a mix of weather and a bad back, I rather hastily set up at 10:30pm last night.

Had a quick look at Saturn to try out the TAL barlow (which just showed up the deficiencies of my eyepieces, I thiink!) and then moved on to have a go at imaging my first DSO.

Used my new polar scope for the first time, but due to not yet having the right size allen key it isn't calibrated properly. Not too far off though and certainly gave better alignment than I've ever had before. It was pretty gusty at times too so maybe that had a hand in the smeared stars also (as well as focus?).

But I'm very happy with it for a first attempt and am spurred on for more!

This is 48 x 15 seconds and 30 darks using the gear in my sig.

M57_18_05_2011_48ex15s_30darks.jpg

Link to comment
Share on other sites
  • Replies 25
  • Created
  • Last Reply
ollypenrice

ollypenrice

Posted
Posted

You're off! Lots more enjoyment to come.

The trailing isn't focus, which seems pretty good. It looks like a classic tracking error but maybe with backlash in there as well. Running slightly heavy on the east side of the RA drive might help.

Olly

Link to comment
Share on other sites
Brent

Brent

Posted
  • Author
Posted

Thanks for all the positive comments everyone :eek:

It looks like a classic tracking error but maybe with backlash in there as well.

Olly

I've gone back over the subs in sequence and you are right - the frame moves forwards and then back on itself slightly four or five times over the 60 subs.

Running slightly heavy on the east side of the RA drive might help.

Olly

Would you mind explaining this please Olly? I don't have a clue, lol

Could I also ask for advice on using a 2x or 3x barlow on this object. I tried with both but couldn't get anywhere near focus with the camera inserted - is that down to a lack of inward travel? Can I do anything to fix it?

Below is the best sub of the bunch with regards sharpness. To my very amateur eye, the colours look much more accurate than in the final image - am I right, and can I fix this in the final image?

Capture19_05_201101_47_33_40.png

Sorry for all the questions but you guys know what you are talking about!

Link to comment
Share on other sites
MikeWilson

MikeWilson

Posted
Posted

Well done!

And re: "Would you mind explaining this please Olly? I don't have a clue, lol "

Olly is suggesting that you should ensure that your scope is balanced so that the east side is heavier. This is because the RA motor is then working against some pressure which helps reduce the backlash that occurs when one of the gears finishes it's cycle and would cause the scope to 'bounce'.

Just ensure that your scope is heavier on the east, either the counterweights are on the east (in which case, slide them down to make them heavier) or the scope is on the east (in which case, slide the counterweights up to make the scope heavier).

Hope this helps!

Mike

Link to comment
Share on other sites
Brent

Brent

Posted
  • Author
Posted

Oh well, it wasn't to be tonight.

I struggled for an age with the focus, then when I had it right the thin high clouds rolled in!

One positive though - as I waited for the cloud to clear (which it didn't), I ramped the exposures up to 60 seconds just to get a better view through the cloud, and those stars seemed awfully round :). So it seems I got rid of the backlash with your help guys, thanks again. From what I've read 60 secs shouldn't really be possible on the EQ3-2 without guiding and I wish I had saved some of the preview subs to look at a little closer. Bodes well for the next clear night though hopefully!

Link to comment
Share on other sites
Brent

Brent

Posted
  • Author
Posted

Thanks Keith & Rob :p

I'm not really happy with the colour, it seemed much better in the subs (see my sub image in the post further up). I've messed around in Photoshop but ended up leaving the raw output of DSS as I can't get them back! Anybody have any ideas why it came out coloured so differently?

No, no, no, Bode's is in an entirely different part of the sky, near Ursa Major. :)

Lol, yes I thought someone might come back with similar when I posted it :p Hoping for Bode's as my next target when I've revisited M57 with longer subs :headbang:

Link to comment
Share on other sites
RikM

RikM

Posted
Posted

Well done. Keep at it and the images will get better and better.

With a bit of tinkering, no wind and good polar alignment I can get 2 min unguided out of my EQ3-2 with a 150P. Setting the balance point so the motor has something to pull against is a top tip.

Link to comment
Share on other sites
JKB

JKB

Posted
Posted
Well done. Keep at it and the images will get better and better.

With a bit of tinkering, no wind and good polar alignment I can get 2 min unguided out of my EQ3-2 with a 150P. Setting the balance point so the motor has something to pull against is a top tip.

Nice Image! As quoted with a little fiddling and good polar align I get 2mins unguided, couple of times just over!

BTW what camera did you use?

Cheers

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.