Cassiopiea with AstroTrac - Need to work on my processing....

[Digz]

So, last night I actually got the AT out after collimating and fettling the polarscope:

1hr comprised of 2min subs.

Darks, Flats

Nikon D7000, 50mm @ f4 ISO800

Stacked in Regim with DBE to remove an horrific gradient caused by the moon.

Stretched (poorly) in Photoshop.

I really need to work on my processing - any advice greatly appreciated. Oh and probably sort out my flats (or clean my sensor)

2min subs were showing nice round stars, I didn't press exposure much more than that because of the moon.

Thanks for Looking.

[Richie092]

Nice one Digz. So many stars!

Looking forward to seeing how long you can eventually expose for now it is collimated.

[Digz]

Looking forward to seeing how long you can eventually expose for now it is collimated.

I could easily get 3min before so hopefully, on a dark night I can get around 3-5min. I limited to 2min due to the moon....grrr......

[jgs001]

Looks good Lee... You should be able to hit 5 minutes with the AT and a 50mm... prob not under such a bright moon of course . 

[iksose7]

Looking good Lee, i done a similar shot to this with the AT but stupidly didnt think about framing it properly with the double cluster, which you have done a nice job on! You should be able to get 10 minutes with the 50mm quite easily now, so long as you are under dark skies!

There does appear to be appear to be kind of fog over the image though? Not sure what that might be. What steps are you taking in processing? Do you have an image of the histogram?

[Digz]

Thanks chaps. I think I lucked out with framing

@iksose7

The images were stacked in regim which I also used to remove a horrendous gradient.

Exported as tiff to PS.

In PS I performed several histogram stretches.

The first to align channels the subsequent iterations to bring the black and white sliders under the edges if the histogram, if that makes sense? I was careful not to clip the image. This helped widen out the histogram.

That was pretty much it.

TBH most of images look like that so I'm definitely (and I'll freely admit this) not doing it right. To be honest I don't know what I'm doing really.

Any tips you have will be greatly received.

As for the histogram I can get an image of that from my lappy and I'll try and get it uploaded tomorrow.

[iksose7]

Hmmm, i'm not familiar with Regim. 

It sounds like you are taking the right steps but i would suggest a re-process without the gradient remover just to see if it makes a difference. I usually deal with gradients mid-end of a process.

Check out Warren Kellers tutorials, even though these are the free ones they helped me break major barriers in my post processing!

http://www.ip4ap.com/freetutorials.htm

If you are still struggling then you could upload the RAW file so others can have a go

[bodtwo]

I think i need to collimate my AT. I also need to look where i'm pointing, last time out i got a quarter of the frame with the side of the house in. I'd swapped from a 50 to the 24. Schoolboy error!

[symesie04]

Such a busy area of sky, nice image. Interesting images of the before collimation. It really was quite a bit out wasnt it?. Did you find it tricky even with the new thumb screws? And where did you get the thumb screws and which ones out of interest? I really need to do mine

[Digz]

Hmmm, i'm not familiar with Regim. 

It sounds like you are taking the right steps but i would suggest a re-process without the gradient remover just to see if it makes a difference. I usually deal with gradients mid-end of a process.

Check out Warren Kellers tutorials, even though these are the free ones they helped me break major barriers in my post processing!

http://www.ip4ap.com/freetutorials.htm

If you are still struggling then you could upload the RAW file so others can have a go

  

Thanks for the advice, I'll give it a whirl at the weekend, I'm sure I saved a stacked image before the gradient removal.

As for regim, I'm new to it as well. I can use it in the mac which is good and its free (and has a good gradient removal tool as well)

Such a busy area of sky, nice image. Interesting images of the before collimation. It really was quite a bit out wasnt it?. Did you find it tricky even with the new thumb screws? And where did you get the thumb screws and which ones out of interest? I really need to do mine

I was surprised how out of collimation the polarscope was as well. Using the thumbscrews certainly made the process easier to complete. The thumbscrews were from 365Astronomy, if you check my thread (http://stargazerslounge.com/topic/203486-astrotrac-polar-scope-collimation/) there should be a link.

[symesie04]

Thanks for the info Lee. Reading your original post i guess the reason the scope falls out so much would be the extra weight of the thumbscrews. I have to say i find it a concern that so much collimation (scope and arm) needs to be performed on what is a quite expensive piece of kit. If im honest although in design i think the Astrotrac is a great product the build quality in my opinion is rather poor. WIth my polarscope i had no feedback from the on/off switch which resulted in it being overturned and thereby snapping the connection wire inside. Not easy to re solder i can say. I had to re-adjust the focus on it as it was way out and re-align the slot for the illumination as it was quite dim. Then there is the wedge which unfortunately has a tendency to slip and im considering if to send back for repair or just to buy a manfrotto head instead. On that regard very disappointed, however when it works its great.

[Digz]

I must admit my illuminator has given up the ghost. I need to get some new batteries just to make sure.

[LukeSkywatcher]

Great image. Cassi is a bit difficult to make out clearly because of the vast amount of stars. Could be just my eyes or monitor. The double cluster is looking great.

Nicely done. Those astrotrac certainly do a brilliant job.

[Digz]

Ok, here is the same image, without any gradient removal, stretched as per the first image.

See how bad the gradient is........

I might see if the file can be put back into Regim to remove the gradient as I am not aware of of PS plugin that works on a mac?