1st real DSO - M81/2 - please help!

[dc509]

Finally had a chance to use the new Atik 383 mono with the SW ED100 (unguided). Took 29x 60s luminance subs, + a few darks, tried fiddling with the histograms in DSS - looked awful but was apparently only using 5 of the subs. Tried using Dawn, it gave a better initial result, then tinkered with PS and managed to get this image. Any help gratefully received. Am I right in thinking that my fundamental problem is that I do not have enough subs?

Thanks

Duncan

[Zakalwe]

I'm no expert, but I think that the sub length seems quite short?

Also, try this tutorial on DSS...I found it very iseful and it has made my DSS work a lot easier (especially the bit about tweaking the final image in DSS)

[Digz]

Can you tell us what settings you used in DSS. It seems strange that only 5 subs were stacked.

As Zakalwe said, longer subs will certainly help by allowing you to capture more signal in each sub to stack.

EDIT: If you want to, you could put your original subs on dropbox so we can have a go at stacking them and editing?

[Jannis]

A quick play with the levels in PS with the jpg. there are details there for sure. but more stacked would surly help. i think the problem is that DSS is Very picky about what's a star and not. the slightest out of focuse or startrail and it refuses to stack for you. how many stars does DSS say it detects in the averge sub you have loaded?

However, if you compare it to my attemps, wich DSS didn't have any problems with stacking 95% of, it's not much difference in the stars i think?

http://jannis.no-ip.info/astro/full/M81%20M82%20143%20frames%20at%2030%20sec.jpg

What i did when DSS was arguing with me about what was a star and not, i simple resized the pics much smaller and save as TIFF, Then the stars had small enough pixels for DSS to agree with me they was actually stars, and stack them all perfectly.

[dc509]

Thanks for the help everyone. What has been useful, apart from the clear advice, is knowing that processing can yield significant results. As a beginner to DSOs, it's very difficult to know what is possible from the early feeble images that emerge from the camera - no matter how much one reads, the "art" is something that needs to be learned by practice and is not easy to describe in a manual. I looked at the subs and could not visualise the path to a final image. I know that many of the compromises I made (e.g. I've not yet got guiding working for me, so I used short subs) have actually made an impact beyond my original calculations - I did not understand that DSS would reject subs because of trails, for example.

Just goes to show what a steep learning curve it is! I must admit I'm enjoying it though. My biggest problem is that I get to have a go 1 night every month or two at the moment!

Thanks again for the help. As ever, this forum is a goldmine of information and I'm very grateful for the assistance.

d

[Jannis]

I've been using DSS for almost 2 years now, still learning something new about it almost every time i use it...

And i feel your pain, i can only get OK seeing condition and time enough 1-2 times a month, if that. and from april untill october, it's way too bright here in norway to use teh scope for anything but the moon anyway...