First Photos - Break em down for me!

[JP50515]

Hey guys,

 

New here, and to AP, but not astronomy. Been doing visual for a few years now.

 

Got out for the first time last night with my new SW 130PDS, and Sirius mount. 

Camera is a Canon 450D - no CC or filters.

 

Both of these pics are single exposures. M42 I honestly can't remember what it was set to...ISO800 for 60s maybe?

The Betelgeuse pic was a test frame that I looked at after the session and was like...oh dayum that's kind cool. 

 

Anyway, I'm super stoked by how well these turned out for being a super noob in AP, and looking for advice on how to make them better.

(obviously stacked subs would have been the obvious answer)

Is it Coma in the M42 pic that's making the stars eggy?

 

Thanks!

[Davey-T]

Good start, onwards and upwards , as you say stacking more subs will help also dithering when using a DSLR can help the background, yours looks a bit too black.

Your exposure settings are saved in the Exif file with the image to check what you used.

Dave

[beka]

Hi JP50515, I am not really an astrophotography expert but I think it is a  good start. Your images seem to have artifacts, visible around the stars and in the blocky appearance of the fainter parts of the nebula. My guess is that it could be due to the quality of image compression or inadequate color depth. You should make sure you are using the RAW image format on the camera if your are not already doing so.

Cheers!

[JP50515]

Just now, beka said:

Hi JP50515, I am not really an astrophotography expert but I think it is a  good start. Your images seem to have artifacts, visible around the stars and in the blocky appearance of the fainter parts of the nebula. My guess is that it could be due to the quality of image compression or inadequate color depth. You should make sure you are using the RAW image format on the camera if your are not already doing so.

Cheers!

Hey Beka,

 

Yeah I see what you're talking about. I was definitely in RAW so that's probably not what's causing it. I would like to get to the bottom of whatever it is that's doing it though. 

 

Thanks!

[happy-kat]

I don't think that is coma. Coma is edge of field distortion you have eggy stars in the middle. Eggy or triangles.

[Shibby]

Nice first images - better than mine were! You'll find yourself on a long slippery slope, now

As you guessed, stacking multiple subs will make a vast improvement. Then you'll be able to process a bit more carefully - the black point looks clipped to me, giving you a black background and possibly losing some of the fainter stuff (although this will be noisy with just 1 sub).

The eggy stars is most likely due to tracking errors / poor polar alignment.

[JP50515]

2 hours ago, Shibby said:

Nice first images - better than mine were! You'll find yourself on a long slippery slope, now

As you guessed, stacking multiple subs will make a vast improvement. Then you'll be able to process a bit more carefully - the black point looks clipped to me, giving you a black background and possibly losing some of the fainter stuff (although this will be noisy with just 1 sub).

The eggy stars is most likely due to tracking errors / poor polar alignment.

Poor polar alignment is my guess. No view of polaris so I had to drift...first time doing that. 

[The-MathMog]

The shape of the stars very likely is a case of, sub length being too close to the limitations of the tracking accuracy. Drifting, if done thoroughly of course, will be a lot more accurate than by using polaris as a guide. But nice pictures nonetheless. For 1 minute subs you are at least somewhat polar aligned. I know for one, that my images didn't look like this, after my first nights with an equatorial mount
Your background is quite black too, so I think you could also try increasing the ISO and then maybe decrease the exposure length, to improve the star shapes. And then of course shoot several images that you then can stack. Even just stacking say 2 or 4 images will greatly improve an image.
Other things to consider is, without guiding, periodic errors in the gears can become a bigger issue with "longer" subs, making every "x" number of image not perfect. And lastly, wind could also be a cause, (if it was windy of course), even for a good steady mount.
But great work! I am a bit in the same boat as you, having started with astrophotography not too long ago and gradually learning every nook and cranny of what can make a better image