Help with Deep Sky Stacker if possible

[Prador]

After a bit of help if possible.

Once the mist departed I managed to get a total of 17 mins exposure on M31 last night but I am struggling with the post processing

I saved the files as RAW+JPEG using a 1100d but when I check the lights/darks and stack (only the CR2 files), the resulting image in DDS is very streched vertically, squashed horizontally and does not look anything like the original picture.

If I try to process the jpegs I get an image I would expect and I can manipulate it but I do not want to work with jpeg due to the compression jpegs have.

I am very new to imaging and I am encouraged by my results but a satisfactory end result eludes me.

I will post a screenshot of what I mean when I return home from work. I am after a bit of advice if I may as its probably a noob mistake I am making.

Many thanks and all hail the clear skies

Dave

[Stephen]

I think you need to download the latest beta version rather than the latest released version to work with the 1100D

http://tech.groups.yahoo.com/group/DeepSkyStacker/

[Prador]

Thank you very much for that link.

It seems my version 3.3.0 does not like CR2 RAW files. I didnt even know they came in different types

:always learning:

Dave

[Tinker1947]

As Stephen said, get the beta version it works on my CR2's.....

[squeaky]

Yep. The beta works fine for CR2 files from my 550D too.

[jgs001]

Thank you very much for that link.

It seems my version 3.3.0 does not like CR2 RAW files. I didnt even know they came in different types

:always learning:

Dave

Dave, it's not that DSS doesn't like CR2 raw files, the current release handles my 450d CR2's without issue. The problem is, that as the cameras update and new models are released. the raw processing software needs to be updated to match the new camera models, otherwise the software doesn't know how to decode the image, and one of the results is as you have seen.

[mikehab]

Hi,

I'm having big problems with DSS - I just can't get it to stack anything! Help! I've added my lights and darks, checked & registered all the frames, then I calculate the detection threshold and adjust it to between 10 and 50 stars (e.g. 16). Then I tell it to go off and it *always* fails saying that it will only stack just one out of 'N' frames. I've tried following various tutorials step by step, copying exactly the same settings etc. but no matter way I do it always fails to stack, saying it will only stack one frame.

What am I doing wrong?

Images are Canon EOS 60D RAWs - and I'm using the latest DSS "3.3.3 beta47" version as the previous 3.3.2 version couldn't handle 60D RAWs.

I'm just trying to stack 4 lights + 3 darks - yet that still fails, complaining that it will only stack one frame.

Getting really disallusioned now as I haven't been able to stack any of my DSO images :-( HELP! (please)

Thanks,

Mike

[Andy_E]

Have you checked for star trails on your images? DSS only tends to recognise round (ish) objects as stars.

[mikehab]

Yep - I removed the 'duff' frames, leaving only the frames with good round(ish) stars. Is there a minimum number of frames and/or stars that DSS needs to work with? I'm assuming it should be possible to stack just (say) 4 lights and 3x darks? Does anyone have a sample set of 'good' lights & darks that I can play/test with to check whether it's my images that are poor quality or whether there's something fundamentally wrong with my DSS set-up...?

Thanks,

Mike

[squeaky]

Try setting the threshold to give you roughly as many "found" stars as you estimate there might be in your image.

You can do this by clicking on the "Advanced" tab when on the register bit and have it compute the number of stars. If you can't get the right (ish) number with noise on, try it with noise off.

I know "the book" says it only needs two stars - but any time I have it set like that it all too often will only stack one sub. Mind you - I've yet to hand it any really good subs because I've got tracking problems and still haven't found the best settings for the camera yet.

EDIT: Oh, and on the stacking page - try the "mosaic" option.

[mikehab]

Try setting the threshold to give you roughly as many "found" stars as you estimate there might be in your image.

You can do this by clicking on the "Advanced" tab when on the register bit and have it compute the number of stars. If you can't get the right (ish) number with noise on, try it with noise off.

I know "the book" says it only needs two stars - but any time I have it set like that it all too often will only stack one sub. Mind you - I've yet to hand it any really good subs because I've got tracking problems and still haven't found the best settings for the camera yet.

EDIT: Oh, and on the stacking page - try the "mosaic" option.

Yep - done both. I adjust the star detection threshold value such that it identifies 16 stars (tried with and without noise reduction ticked), and I also have the 'mosaic' option selected, with the Median Kappa-Sigma clipping with a Kappa of 2.00 and Number of iterations of 5 (defaults). Basically I've done everything it says in this tutorial :

http://flintstonesta...acker-tutorial/

Yet I always get an error/warning dialog saying it's only going to stack 1 out of the 4 frames.

[squeaky]

I'm up to my ears tweaking the clutches on my dob AZ Auto mount right now, (just having a quick coffee break), but I'd guess that the tutorial you posted is very similar to this one....

.

[url="http://www.youtube.com/watch?v=UWWaKkCUm6c"]http://www.youtube.com/watch?v=UWWaKkCUm6c [/url]

Um... you're still setting the threshold for 16 stars? Is that all you've got in your actual sub? If you think you have more stars than 16 then set the threshold to show you more stars.

Can you attach your subs to a (few?) post here? Or post them on line somewhere? No need for the darks just for testing settings

[Prador]

As I am a beginner I would try the following:

Instead of struggling with your current set of subs maybe take another set of subs of a different object. If you can successfully stack them you can safely eliminate how you are using/controlling DSS. Your tube is f13 and will amplify any tracking errors so keep the exposure length short

Are your images taken at the same ISO level?

Also, does the fact you are using a alt/az mount affect the the image (field rotation)? Somebody with greater knowledge than me (not hard I can assure you) would have to confirm all this as I might be talking rubbish.

[dph1nm]

DSS needs a minimum of 8 stars to align I think. Just do the 'register checked pictures' bit on its own and check carefully that each image does have >8 stars detected in the information list at the bottom of the DSS window. Then do the 'compute offsets' and check that dx and dy offsets exist for all the images. If you have 8+ stars and they don't have a dx,dy it probably means that they are not really stars! To check this use the edit stars function button (click on one of the images to display it then the button will be at the bottom of the right edge of the image). This will show you what DSS has detected as stars.

NigelM