My first pic M42

[Insane Climber]

A pretty crappy shot but im pleased to be gettin somewhere. Gimme some tips please. for some reason the stars burn in way befor i can get much nebulosity showing.

8 x 10 sec exposures at iso 400 unguided

8" newt, Olympus E-300 @ primefocus

[bojan]

Stars have VERY high surface brightness, that is why they will always burn in... If you want to avoid this you will have to use HDR techniques..
Otherwise, the image is pretty good.
You have some coma visible at the edges and in corners, I am guessing you do not have coma corrector?
All in all, I would be very pleased in your place :-)

[gregbradley]

A great start. I wish my initial images were that good.

A Newtonian will need a coma corrector to correct the stars at the edges of the image from being elongated. There are a couple on the market. Televue makes a Paracorr (spelling?).

Also 10 seconds is showing tracking errors which means your mount is not polar aligned. That is a whole procedure in itself and one best learned early on as you will use it over and over - its a basic.

Most mounts even if cheap should be able to achieve 30 - 60 second unguided images with fairly round stars if the polar alignment is good with a DSLR and 8 inch Newt.

M42 burns out the core with any camera no matter how expensive because it is very bright. Usually one takes a series of short exposures like you have and a number of longer ones and puts them together using Photoshop trickery.

Greg.

[Quark]

Hi Jason,

Isn't it satisfying, actually getting something, when you first start imaging. Been down that path with 35mm film many years ago.

I am sure you will get some good advice from more expert DSLR imagers.
You really need to be tracking your prime focus images. The magnification, even at prime focus, with your scope would be way to high to expect to achieve well resolved point source stars.

Also, how are you focusing the scope. Often what looks focused just by eye is not the sharpest focus. There is a very extensive thread on IIS regarding the use of the Bahtinov Mask and how to build one. I have made one up for my 16" Newt and it makes focusing very easy and extremely accurate.
Another consideration is the collimation of your scope, if it is out then the star images will be bloated.

Just a few thoughts.
Regards
Trevor

[Insane Climber]

Thanks for the advice there guy's. Ah so thats what a parracore is, will look into that one. And yea still struggeling with alignment, i think i understand how the drift alignment works but haven't been very successful yet. No chance of seeing the pole from my place. Will keep trying though, im well hooked now.

[renormalised]

Great first shot there, Jason. Now you've seen what a few short exposures can do, get your paracorr, fix the polar alignment and guide the scope. Take exactly the same subs as you did there. Then do a run of 5-10 min subs, say 10 or so. Then do the PS jiggery pokery (blend the shorts with the longs) and you'll have a great image:)

[renormalised]

You don't need to see the pole....once you've set your latitude scale, and aligned your scope with the SCP as best you can (try this....you know where South is on a compass. Find out what your magnetic declination is for your location then subtract or add that from/to due magnetic south...i.e. towards the east or west depending on your local mag dec. That'll give you an approximate south bearing to align your scope along), then use the drift method to get it aligned more precisely.

[gregbradley]

Drift alignment is a skill well worth spending some time mastering.

There are several writeups on this on the net.

The only thing I would add is these writeups do not adequately define star drifting south or north. What does that mean exactly??

Star drifting north is defined by moving the end of the scope towards the north and seeing which way the star moves by looking through an eyepiece or taking an image and comparing it to where it was before physically giving the end of the scope a slight push to the north whilst looking or imaging (diagonals etc. make that hard to guess without doing an actual physical trial). South then is opposite to that.

Once you know that it is easy.

Greg.

[Insane Climber]

Thanks for the comments and encouragement there everyone, i really appreciate it.

Jas