M1 HA

[pyrasanth]

I captured the image below of M1 the Crab Nebula using a Baader 2 " HA filter 40 120 second subs. Celestron RASA & Atik 460.  The clouds stopped me taking more subs but the data is strong. Let me know what you think.

The wind was a bit rough so I needed rapid guiding. Stars not as round as they could be.

Clear skies to you all.

[MarsG76]

awesome crab... well done... stars look round to me.

[pyrasanth]

When we get better weather I will capture the OIII & SII but it looks like we have horrible weather for the foreseeable future. 

[Scott]

lovely detail in the crab but for me, the sky's a bit unnatural. have you clipped the blackpoint?

[pyrasanth]

lovely detail in the crab but for me, the sky's a bit unnatural. have you clipped the blackpoint?

This was a rough image produced from a scaled image in Ccdstack2. When I look at the histogram in Photoshop the black is a hard line to the far left. Only by putting in an adjustment layer can I change the sky background so the difficulty lies I think with the post processing in Ccdstack2. I don't know of a way yet to get a more balanced histogram in Ccdstack before the export of the scaled data. I may redo the whole process in Pixinsight & see if I get a better result from this. I'm not terribly good yet at level balance. I have posted a new image below with the layer adjustment layer so even though it has brightened the sky there is no more detail to be had which suggests clipping before it gets to Photoshop.

[laudropb]

Very nice image lots of detail and the stars do not look too bad to me.

[Scott]

To me that sky looks a lot more natural. I've not used ccdstack so have no idea about it.

Its a cracking image of one of my favorite targets

[Hytham]

I prefer your 2nd rendition.

What software suite do you use to process?

[ChrisLX200]

Wow, so similar to the first light image I took with my Altair Astro RC8 a couple weeks ago! Mine took much longer though - 7 x 1200s. (Atik 490EX @ 2x2, Astrodon 3nM). The comparison is interesting for the difference between 3nM and 7nM Ha filters so I hope you don't mind my posting an image into your thread? Just ask and I'll take it out.

ChrisH

[pyrasanth]

I prefer your 2nd rendition.

What software suite do you use to process?

This was processed mostly using Ccdstack2 to export a scaled image then an adjustment layer applied with Photoshop to lighten the background. I also use Pixinsight but that can take longer to produce a finished result.

[pyrasanth]

Wow, so similar to the first light image I took with my Altair Astro RC8 a couple weeks ago! Mine took much longer though - 7 x 1200s. (Atik 490EX @ 2x2, Astrodon 3nM). The comparison is interesting for the difference between 3nM and 7nM Ha filters so I hope you don't mind my posting an image into your thread? Just ask and I'll take it out.

ChrisH

Hi ChrisH,

No problem at all posting your image in this thread. It is interesting to see that there is not a lot of difference between the Baader filter & the 3nm Astrodon. It might make a difference on some very faint objects but I seem to get reasonable results with the less expensive filter. I might consider the astrodon for the OIII as this seems to suffer a lot from light pollution effects where I live. I notice that the HA filters give a very black background on my system- do you find this? it is often pointed out that I've clipped the background as in the first image but it come out this black mostly with no processing!

I noticed you binned at 2x2 on the 490EX this has undoubtedly increased the sensitivity of the CCD but you might have lost detail if you get those rare moments of good seeing. I'm trying to always use 1x1 on the Atik 460- I know you've got slightly more resolution & a smaller pixel size. Binning makes guiding easier but I'm a sucker for punishment.

I'm waiting for my C11 Edge to come back from the USA- it meet a calamity so it's being repaired & then I can swap the OTA's to  get a greater image scale & use the ATik 11000 for a big flat field using on axis guiding through the innovations foresight ONAG.