Pleiades

[Likwid]

Hello, I have been spending as much time as possible outside when the weather permits practicing. My current camera is a Canon Rebel XS Astro modified by myself (IR-Cut Filter left in) w/ Astronomik CLS Clip in filter. For this shot, I used an Orion ST80 at prime focus on a Sky Watcher Star Adventurer. I did around 80 frames at 45 seconds, but it was a little windy and I was only able to keep 65 of them. I took 15 dark frames right after the lights. There was no cloud cover, transparency and seeing were both above average in my area. I don't understand why I can't see more in this shot. I think there are 2 possibilities, either I am not able to pull enough out of the image in Photoshop or my frames should be longer than 45 seconds. I know the general rule of thumb is over an hour of integration, but I should be able to see more than this at around 48 minutes. Can anyone shed some light on this please? If needed I can upload the original TIFF file from DSS. Thank you!

(I know about the distortion in the corners, I was excited to see what I could pull from the image and didn't bother with fixing it)

[jazza]

Hi Likwid.
I had a quick look in PS and just doing some basic stretching using just levels in photoshop it seems like you do see some nebulosity.

I made no attempts to keep the star size under control here, was just looking in 3s to see what was there.
If you look at the histogram of your posted image, all the information is in a tiny region on the left. You need to 'zoom in' to that region to see the range of light you have captured.

If that makes sense.
I'm sure someone else here will give you a better explanation but just a quick 'don't lose hope' it's not so bad  GJ!

 

[Likwid]

That makes sense! Thanks! I was hoping it was something that I wasn't doing correctly in post. Now I guess I have to watch a bunch of videos to learn more about editing!

[bobro]

Can you convert one of the raw subs to a jpeg and post it (no editing)? Also, what ISO was used for the 45 sec exposures? These will help with a response.

[Likwid]

Hello bobro, here is one of the subs. 45 seconds, 800 ISO, unedited and straight from BackyardEOS output. Thanks!

[Uranium235]

There might be more there than you think, what you need to do is post the raw stack (either a 16bit fits or tiff format), then someone can have a go at getting the most out if it.

[bobro]

Your capture of a single sub is what would be expected for 45 secs. A rough stretch (no colour , saturation change) gives that attached image.

To give better colour in a DSS stacked image, set saturation to about 20% and align the RGB as shown in the attached screen captures. That will give an image with colour that is not dark. Not everyone does it this way as it depends on how images are subsequently processed.

[Starwiz]

I would try longer exposures.

If you do lots of shorter exposures it will reduce the noise and improve definition when stacked, but if you have insufficient data in each sub, stacking will not bring out something that's not there in the first place.

[Likwid]

Oh wow, thanks for the info and the settings bobro! Do I have to do that in DSS or can I do it in Photoshop? Thanks Starwiz, unfortunately it was a little windy and I was already pushing it with 45 second exposures. I really have to upgrade my Star Adventurer. So I did a re-edit and here is what I have so far, it looks much better than the original but I am going to keep playing with settings and see if I can do any better.

[bobro]

8 hours ago, Likwid said:

Do I have to do that in DSS or can I do it in Photoshop?

In principle you can do it either way. I use GIMP and find it easiest to do the colour corrections in DSS.