M51

[Daveskywill (David)]

Here's my M51 picture:

See my image quality is coming up?

The polar alignment is getting better.

It's a bit grainy though. Used a T2i. Plan to build a cooler for it.

Any advice?

David

[Joshua Bunn (Joshua)]

Nice one Dave,

Originally Posted by Daveskywill

Any advice?

David

You could take some flat frames and apply them. Did you do darks?
Guiding needs some work, unless thats an optical aberation. looks like its in different directions so more likely the later - or its field rotation in which case you need to be better polar aligned. What were your sub lengths?

more time will help get rid of the graininess.

Is that light polution? if so, you may want to look at a LP filter.

Josh

[Lee]

I wish I could bag M51 from here!
Not too bad, stars are round enough to start - the noise will settle down as you stack more and more exposures....

[Daveskywill (David)]

There were 6 light frames and 1 dark.

They were all at 4 min at 3200 ISO.

You're right flats would make it look better with no gradient and so forth.

Now I need to learn to make those flats.

There was no Guiding. Although I could do it. As I do have an ST-2000XCM

CCD. My equipment was a Meade LX200GPS 10" F10 and a Canon Rebel T2i.

PS: I'm not sure that my polar alignment is spot on. It's a fork mount too

and got to be careful when taking those exposures not to jiggle anything,

that's a weak part, the forks.

Also got the drift align so good I could do a 4 minute exposure without

"real" trailing (no guiding) with a barlow. Then went to no barlow and short-

er exposures and it started trailing. That seemed strange. This happens

sometimes, so I played around with the "tracking rate" and found that a

value of +10 worked well. But I might be subject to change with declination.

But it's got an 80mm scope piggyback mounted with an ADM system.

So we added counterweights, but maybe it doesn't always stay balanced?

But PPS: My guide program is PhD. Part of the battle is that I need

to learn these techniques. My mom is already concerned that I'm spending

too much money on it.

What should I do?

Thanks
David

[Joshua Bunn (Joshua)]

Originally Posted by Daveskywill

Also got the drift align so good I could do a 4 minute exposure without

"real" trailing (no guiding) with a barlow. Then went to no barlow and short-

er exposures and it started trailing. That seemed strange.
David

You were using a wedge?

Also, a ccd image will be far more sensitive to polar misalignment drift than you eye. So try googling "ccd drift alignment" and you'll get all sorts of good advice.

Josh

[Daveskywill (David)]

Hi: Well the drift I did was using the Star-Targ 2_0 program

(reticle program) and followed the directions and overlayed it over

my CCD program (CCDSoft) using my ST-2000XCM CCD camera. But

even though I followed this, like you say I think the alignment is still off.

You know one knob for azimuth and another for altitude. And followed it.

But the observatory building I'm in has a bit higher walls (sort of needed to

allow the roof to roll shut) so I'm not ever able to look as low to the horizon

for my star in the east / or west. Thank you for your help!

[Daveskywill (David)]

Yes a wedge

A Meade Superwedge.

Even though those scope/mount packages are usually weak

with the fork arms