After waiting (for what seemed like) a very long 3 weeks, there was finally a decent clear night in the UK last night. Im fairly new to astrophotography and ive never used the Meade DSI before so i thought id just do some test exposures of M42 to get a feel for it. However, when i came to stack them in DeepSkyStacker, the image became quite distorted. Upon further inspection, it appears as though my original frames (prior to stacking) are also distorted, though this is not visible unless the brightness/contrast is increased. Any ideas as to what is causing this and how to fix it?

Thanks in advance!
 

Just had a thought - could the distortion be due to me saving the images as JPEG's rather than TIF's or Fits?

Did you have tracking on?  I would suggest that you go to settings and "save all uncombined images" in fits3p.  That way you can reprocess the subs later and throw away bad ones.

CFB

Yep, tracking was on and i have all of the uncombined exposures saved. They're all distorted. The only thing i can think of is that its the file format i saved them in thats caused it.

Can you post one of the images so that we can take a look at it. Then we might be able to help determine your problem.. Even if you save the individual images as JPG, each image should not be distorted unless there is some other problem. Maybe it is the focus, or it could even be collimation.. But we won't know unless we can see it..

Have A Nice __________

I couldn't get you link to work,

But,  If you use the DSI and, You plan on stacking it with any other program other than Meade's Software, you need to save it in the right Format. 

You will lose data with a Jpeg,   and with a Fits3p or Fits it will only work with certain software.

If deep sky stacker can use the Tiff format then in your process dialog box you should choose the Tiff format

 The best way though I think would be to use the Fits Format to stack and align with the Meade software first, then the final stacked image can be saved or exported in the Tiff or Fits format,  then you can process the image in whatever final post processing you want that allows for those formats.

Dennis

I think it must have something to do with brightness and contrast levels.  Try combining the images in Envision with lower levels of brightness and contrast.  Also there is an excellent DSI group in Yahoo groups, someone there can help diagnose the problem.

 The image you posted is enlarged and pixelated (if that is a word).

Your image is 748x577 pixels. Mine are 648x488 pixels.

I would look and see what the settings are for the size of the image to be saved. Although 100 pixels is not a large amount to enlarge it will distort an image.

It has been a while since I used the DSI so I am not sure if there is a setting to specify the size of the image  but the problem you are having is an image that has been enlarged too much. The tracking is good as the stars are not elongated. It appears you cropped the image and then re-sized it too much as an 8" Newtonian should not fill the entire  image with the nebula. I have a shot of M42 with my 8" SCT at 2000 mm focal length and the nebula is smaller than yours.

Can you post an original un-touched image. 

TheHarvester:

The image you posted is enlarged and pixelated (if that is a word).

That's the word and that is exactly what I see also.. The Image has been enlarged so much to the point of pixelation..

Have A Nice _________ 

if u have a resource like photoshop or anything, u can easily go to image size, make the resolution 300 and bring the image size.

Hi There

I have been using the DSI for a while and this looks like post processing rather than settings with the DSI itself. If you want a quick test, let Envisage stack the images while you are capturing, that way you can monitor the image live to make sure you are getting good images.

I would also suggest registering with the Meade 4M too make sure you have the very latest software and the Autosuite.Net forum is very helpful as well. The links are on my website.

Whoops just noticed the date on your post, I'm new here. Hopefully you are all sorted out and don't need my advice anymore!

Cheers  Danny

From a DSI Color (original) owner... 

In my experience, the best results I've had are with using AutoStar Envisage 7.05 (available on the Meade web site) for imaging, and even stacking (if the images aren't too far rotated or otherwise misaligned). The trick to stacking in Envisage is to use the Drizzle setting, and draw the boxes around 2 guide stars at opposite ends of the image and as small as the next image will travel. In other words, make the boxes just big enough to capture the (shifted) star in the next image.

I recently tried MaximDL for stacking images, and I can tell you, it is a vast improvement over the stacking capabilities of Envisage. 

If you have rotation free sub exposures, stacking them properly is key to getting an image that can be manipulated further.

I always use .fits and save all uncombined images. With these settings, Envisage produces 4 files for each exposure;

1 blue

1 green

1 red

1 Luminescence

I then (in Envisage or MaximDL) stack all the blue and save as deepskyblue

then all the green and save as deepskygreen, and so on.

Then, in Photoshop, I open each one with the fits Liberator, (available on the ESA/ESO/NASA site)

http://www.spacetelescope.org/projects/fits_liberator/ 

and each into it's own layer, which Photoshop does automatically.

I then use Astronomy Tools Actions in Photoshop http://actions.home.att.net/Astronomy_Tools.html 

to process the different layers so as to view and process them as a color image.

I know it seems like a lot, but with .fits, you have much more control over the image, and your end results will show it. 

 I hope this helps. If you have any questions, please, don't hesitate to ask. That's what this forum is for!

Good luck!