Having trouble on M57

[rfdesigner]

Hi

I've been playing with some data I took last night of M57.

It's a simple luminance image but playing with the thresholds I can reveal some background galaxies and the extended hydrogen plume around M57.

Problem is I'm having trouble getting the right processing steps to bring these details out without damaging the brighter areas or suffering star bloat.

To get this I've had to apply three lots of unsharp masks, wavelet selective noise reduction and two lots of contrast adjustment (all in IRIS)

here is a link to the origional data.

https://dl.dropbox.com/u/44641599/m57_v1.fit

It's not that great, only 1 hour and the dark subtraction isn't yet optimised, but it's good enough to play with.

I'm sure some else can do better than me, in which case I'd like a few pointers please

thanks in advance

Derek

[NickK]

Hmm, just downloading the FITS image now..

I think you're probably pushing the boundaries of the data. You have to push up just the very fine range of values to get what you have out so far..

I did take the liberty - I think with a good drizzle and PSF you could get a very nice M57 out!

[rfdesigner]

Thanks for trying

It's just that I've seen a vew images on the web of M57 showing the background galaxy and try as I might I can't show that without having my stars bloat horribly.

Derek

[Shibby]

Hi Derek, I've never used IRIS but it should have some sort of method for creating a star layer?

I had a quick go in Photoshop but unfortunately made the star layer too small around the brighter stars...

[rfdesigner]

Hi Derek, I've never used IRIS but it should have some sort of method for creating a star layer?

I had a quick go in Photoshop but unfortunately made the star layer too small around the brighter stars...

Now that result is much more like it!

I've not been able to get IRIS to do a star layer, I can manually remove individual stars but can't globally remove them. I've been looking for a new tool to do the job, but so far not decided.

It's good to see that a star layer really is the technique that will work, just need to add it to my tool box.

Derek