To all the astronomy guys out there

[moot]

Yep, I can do 20 frames.

[CptTrips]

This is a good discussion of SNR and stacking:

http://www.samirkharusi.net/sub-exposures.html

Clear Skies,
Wab

[CptTrips]

And if you aren't ready to dish out for ImagesPlus you might try this:

http://deepskystacker.free.fr/english/index.html

Its free.  I've never used it myself, but I've heard good things.

Wab

[moot]

Thanks Wab.

[Jack16]

I tried stacking the images myself with the Deep Space Stacker program and this is what I came up with.



There is still a lot of noise and it's kinda grainy, too, but loads better than the original!

Wab, I sent you the images still if you would like to try.

[CptTrips]

I tried stacking the images myself with the Deep Space Stacker program and this is what I came up with.

Now THATS what I'm talkin about!  Tons better!  Thats sweet!

I might play with it a little but I doubt I'll improve on that.  I might try and see if I can keep the central region from over saturating.  You had some excellent detail in there I think got clipped.  I also remembered I used to use the other program called "Neat Image" to remove some of the noise.  I'll see if it helps at all.

Now, you might have notice that your images had a radial brightening toward the center?  I think thats what flats would help you remove. The good news is, if you want to try that later, you can create pretty good ones any time. Take you scope and camera out in the morning or evening.  Set it up like you were going to image.  Take a white t-shirt or similar and stretch it across the front of the scope and point the scope and a cloudless, evenly illuminated area and take about 10 frames at the same iso and duration as you did your light frames.  Stack and use that master flat frame to calibrate your original data and that should give you an even illumination across the frame.  Then you are only dealing with the targets data not that intruduced by the optical system.

Great work.  Now you just need to start webcaming.

Clear Skies,
Wab   

[CptTrips]

Here is my try:



I only stacked 3 of the 4 images.  One looked really smeared.  Maybe I should have added it anyway. 

Still I think you can see the amazing benefits of stacking.  Look at the improvement over the original single image frame.  Think if you had a stack of 20! 

Now you have a whole new avenue to explore.  Hope to see some more soon and congrats on the fine image!

Clear Skies,
Wab

[CptTrips]

Oh I forgot one last suggestion. 

Once you start taking large number of subframes you might want to look into something like:

http://www.google.com/products/catalog?q=canon+timer+remote+controller+tc-80n3&hl=en&prmd=ivns&resnum=1&biw=1579&bih=1027&wrapid=tlif129674988538310&um=1&ie=UTF-8&cid=3412511021821397184&sa=X&ei=VdVKTcCYI8X6lwfLlIkS&ved=0CFgQ8gIwAQ#

NOTE:  this might not plug into your XTi without an adapter!  They may have fixed that or made a new one.  You'll have to research.

I originally bought one for my 10D and later when I got my XSi realized the plug was different.  There was a guy on the net that sold custom converter plugs and I bought one and it works fine.

It allows you to pre-program the number of frames, the duration of each exposure, and the time delay between frames.  Makes life much simpler.  I set it up, stick it with velcro the the forks of my mount and start it.  I don't have to touch anything again for a couple of hours until its done with the program. 

Wab




I also think you can use ImagesPlus to do this.  The smarts are in the program and they have instructions on how to make the simple bulb cable.