New Stacker

[Nzlowie]

Hi all, new here so please bare with me.... I've always been keen on giving astro photography a try so here we are. I have a canon d60 but not having a lot of luck yet. I've taken various exposures to see what happens. Tonight I shot 20 exposures at 1600 Asa for 10 sec each one had reasonable star detail so I thought that when I stacked them with Deepstar stacking software I thought I'd get a lot more detail. Allas the resulting image was worse than any of the individual shots. Am I doing something wrong? Could I be that my sky area has just too much light pollution?

Looks forward to hearing your thoughts.

Dave

[michaellxv (Michael)]

Hi Dave and to IIS.

I am no expert and I am going through a similar exercise to you. Have a look through my Lemmon thread and post #10 by Screwdriverone it has some great tips on how to use Deep Sky Stacker.

If you are in the suburbs then light polution will be a problem but I am not letting that stop me from practicing. But a trip to dark skies will definitely give better results.

You can probably go longer than 10sec exposure, I have just tried some at 30sec but haven't processed them yet.

Post a sample of what you have and the experts will be able to advise better.

[Tandum (Robin)]

You'll probably need to stretch your data after DSS.
This utube tut shows data stretching in photoshop.
http://www.youtube.com/watch?v=WnPII6YdVBc

This one is pretty long winded and I haven't watched it, but looks at the whole process.
http://www.youtube.com/watch?v=3PEFIUxpzt4

[Nzlowie]

Thanks all
I did a bit more reading and also had a look at the couple of YouTube videos, make it look easy! I tried doing as described but not much luck yet. I think my problem is light pollution as all I get if I increase exposer to 20 sec I loose all the black back ground, just get a muddy gray. May have to wait till I can get some dark sky....

Could this be the issue?

Cheers

[JB80 (Jarrod)]

It could be light pollution(LP) that does make a horrible muddy glow so you could try dropping the time of exposures and the iso down to 400 or 800.

Are you talking about gray after you have stacked it?
Can you upload a couple of pics somewhere to show exactly what you mean?

[Nzlowie]

Hi again
Finally I managed to get some clean images. Took my camera and tripod up to work ( Pilbra), took 20 images iso 1600, f5.6(wanted to make sure of focus) and exposure of 15 sec. It was surprised there was a bit of a trail to the star. Anyway, got the images back home for a decent look, ok detail but as I say a bit of a trail....

Also took 10 dark and 10 offsets so I thought I'd be set to load them to DSS. Loaded all the images and let it do its thing. Had an image, all be it tall and skinny. Saved it as a tif, tried to open it in Gimp. ( don't have PhotoShop)

Trouble is that when I try and open the image in any of my image editors the image is just a blank, black image. Absolutely no detail, not just black that can be lightened, nothing.

Any idea's? Is my process of image collection correct?

Many thanks.

[alistairsam]

Hi,

are you able to post a link to the image or post a jpg version of one sub?
you could upload it to dropbox or astrobin or similar sites.
it'll make it a lot easier to identify the issue.

Cheers

[JB80 (Jarrod)]

Do you have the beta version of DSS?

For some reason DSS makes these tall skinny pictures you describe but can be fixed if you use the beta version.
Download it and try again to see if that makes a difference.

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

[Nzlowie]

Thanks for the help.... I killed the version of DSS I had and reinstalled the beta version and success! The other issue I had was that DSS saved the final as a 32bit file that my Gimp program couldn't read it. I resaved the finished file as a 16 bit and Gimp down graded this to 8 bit that I could process. Now just have to figure out how to bring the best out of the image....

I know everyone is using Photoshop but I can't justify the cost and Gimp does most things, am I too limited by not using Photoshop?

Once again thanks your help.

Dave

[ZeroID (Brent)]

Hi Dave, congrats on your perseverance with it. Processing can be quite a steep learning curve to get something worthwhile out of it all.
Light Pollution can be managed with either a CLS ( Clear Sky) filter or one of any other types that minimise the glare.
Unless you are tracking if you are attempting reasonably high magnification you will get star trails at 10-15 secs.
You don't say what sort of camera or lens and settings you are using but most DSLR widefeilds are done with 35mm or 50mm lens so trailing is not apparent for up to 30 secs.
Processing in 32 bit does not have to be done in Photoshop, the latest GIMP I beleive handles 32 bit but I don't use it. I use FITSWORK but it's a pretty daunting and resource hungry piece of software to come to grips with.

[Nzlowie]

Cheers Brent

I should have mention gear I supose.... Canon D60 and a tamron 18-50, 2.8 lens set at around 35mm.

I stopped it down a couple of stops to make sure focus was correct.

Should I look at a lot more, shorter exposures? Say less than 10 sec?

I'll also get the latest version of gimp, unless you can recommend something else to try...

Do you know of any good tutorials on this type of image processing?

Once again thanks for your help.

Dave