DSS alternatives

[shropshire lad]

Thank you onikkinen I will give it another try.

 

[shropshire lad]

18 hours ago, ONIKKINEN said:

Its worth it to try to get Siril to work for you and it doesn't really take that much getting used to. The easiest way is to use the premade OSC preprocessing script found in Siril. Just create a folder on a drive that has plenty of free space on it (and make this the "home folder" for Siril), create 4 subfolders named lights, darks, biases and flats and then put all the raw frames on these folders and click the script. Siril converts your CR2 files to .fits files and then calibrates them and stacks them. It really is that simple.

Check this tutorial if it still doesn't make sense: https://siril.org/tutorials/first-steps/

If you want to have a drag and drop kind of experience like with DSS you can use Sirilic, which uses Siril to do the stacking but with a simple to use graphical interface.

Check it out here: https://siril.org/docs/sirilic/#the-first-steps-with-sirilic

With Sirilic you can do lots of things you cant really do with DSS, like removing background gradients per subframe (subsky) before stacking which helps a lot if you had an unusually strong gradient for some reason.

Can I use Siril with only light frames, as this may be my problem ... I keep getting an error see below.

14:00:17: Setting CWD (Current Working Directory) to 'C:\Users\Paul Lewis\Pictures\biases'
14:00:17: Running command: convert
14:00:17: No files were found for convert
14:00:17: Error in line 25: 'convert'.
14:00:17: Exiting batch processing.
14:00:17: Setting CWD (Current Working Directory) to 'C:\Users\Paul Lewis\Pictures'
14:00:17: Script execution failed.

Paul

 

[ONIKKINEN]

3 hours ago, shropshire lad said:

Can I use Siril with only light frames, as this may be my problem ... I keep getting an error see below.

14:00:17: Setting CWD (Current Working Directory) to 'C:\Users\Paul Lewis\Pictures\biases'
14:00:17: Running command: convert
14:00:17: No files were found for convert
14:00:17: Error in line 25: 'convert'.
14:00:17: Exiting batch processing.
14:00:17: Setting CWD (Current Working Directory) to 'C:\Users\Paul Lewis\Pictures'
14:00:17: Script execution failed.

Paul

 

Well, the easiest solution would be to take calibration frames. Especially flats are very important, and its really not something that's optional in the long run if you want to get all the data out of your images. For some targets omitting flats is not a big deal, like when the target is small enough to only be in the center of the image but for most targets not taking flats means you will have serious trouble getting a presentable image in the end.

If you dont want to take calibration frames for some reason you can just stack without the script. Its a bit more involved but nothing you cant learn in an afternoon of playing around with it, check this tutorial out: https://siril.org/tutorials/tuto-manual/

If you follow this tutorial but dont have calibration frames, you need to skip all the parts that have anything to do with them. Without flats you will also need to skip the background extraction process, as it requires your image to be reasonably flat to have a chance of working.

Basically just:

1) convert the CR2 files to fits using the conversion tab. Click the + icon and select the images you want to include for stacking. Click "Debayer" on and give the sequence some name and press convert.

2) Register the frames (align them) in the Registration tab. Registration method can be left to Global Star Alignment (deep-sky) and Registration layer is best put to Green, as that has the highest signal to noise ratio in a colour camera. Just click Go register and Siril does its thing.

3) OPTIONAL: Use the Plot tab to inspect the frames and remove the worst ones. I would recommend doing this but its not strictly necessary. I dont have a strict rule on what quality must a frame be to include in stacking but i would just remove the clear outliers.

4) Stacking: You can leave most settings as they are and use Average stacking with rejection, Normalisation as Additive with scaling and Rejection as Winsorized Sigma Clipping with values 3 and 3.

Doing the above will stack your frames without calibration of any kind if you must do that for some reason, but i would recommend you take calibration frames as part of the normal workflow as soon as possible.

 

[shropshire lad]

well thanks again, I am really appreciative of your replies and the extent you have gone to for me (and others reading this)

As it will make my images better I will try and do the calibration frames then at the same time.