Deep Sky Stacker - problems !!!!

[Skipper Billy]

I am having all kinds of issues with DSS - I have tried the latest version and the last stable version and have the same problems.

Problem one is that it always crashes when it tries to save the image when dithering is applied but doesnt when its not.

The second is that when I feed it a list of Jpegs it processes them just fine and the end result is very good but when I feed it the RAW files the end image is almost a pure white image with a pinky cast and no amount of processing will reveal an image.

When I look at the RAW files individually they are all good quality subs. Stacked they are unusable.

Any ideas or alternative programmes ???

The data is from a Canon 1100D and its a powerful i5 laptop with 4 gb RAM.

Thanks in advance.

[Zakalwe]

Firstly, don't use JPEGs. All of the data contained in the dark areas will have been dumped by the compression algorithm. Always, always, always use RAW. Here's a fairly basic article that I created to illustrrate the difference:

Comparison of processing JPEGs and FITS V2.pdf

For DSS, have a look at this tutorial:

http://flintstonestargazing.com/2009/06/26/my-quick-deepskystacker-tutorial/

You probably just need to adjust the RGB layers in DSS before saving the file.

[Alien 13]

I have similar prosessed results that are almost white but i dont seem to have a problem pulling out data in fact i personally prefer this to trying to get data out of a dark stacked image.

I am sure there must be an option in there somewhere to correct this but for me i only hope i never find it.

Alan

[Skipper Billy]

Thanks for the advice - I have my camera setup to save Jpegs and RAW simultaneously as at the moment I can get a result from Jpegs but not from the RAW files but I fully comprehend the need to use RAW files. But until I can get a result from them then any result is better than no result!!!

The histogram from the individual RAW files is good and the individual files look good.

The histogram from the stacked files is completely split to the far extremes of left and right with nothing at all in the middle. I am thinking that all the exposures have been added together instead of stacked???

[Alien 13]

My stacked images are normally like the one shown although some have been brighter.

Alan

[kalasinman]

DSS is quite complex and has a lot of settings, some of which (like drizzle) are problematic. I went through some issues when I started, but got good results when i set everything back to default. I then read DSS help on the left at the bottom thoroughly.

As Zak said, image files and calibration frames must all be in RAW or FITS format. So drag and drop a set of subs, selecting "light" and some darks, selecting"dark". Then click on "Recomended" . DSS will analyze your files and settings, and suggest improvements. Scroll through the list and wherever there are lines in red, double click on the suggestion immediately below. Then click "Register" and DSS will run to completion, creating a TIFF file. I personally don't use DSS tools for any adjustments to the image.

[Johanvk]

I record RAW's an JPG's together. The jpg's for quicklook's by some programs at the telescope, The RAW's for processing. Processed jpg's give awful checkerboard images and mistreat darks and flats. I hoped to use them as last resort, but they are not even good for that, they are useless.

A problem for me is that DSS does not recognize large starimages as "stars" and reject many images for that reason. When operating a telescope with f=5 m that really is a problem. Does anyone have solution for that?

[Zakalwe]

A problem for me is that DSS does not recognize large starimages as "stars" and reject many images for that reason. When operating a telescope with f=5 m that really is a problem. Does anyone have solution for that?

Just before telling it to stack there's an option to tell it how nany % of frames to include. It defaults to 80% (IIRC). Change that to 100% and it will stack all frames.