newbie Ha shot 23/09/2015 lunt 35

[Joseki]

There's a lot of cloud around today so I wasn't able to finish this off .. but I'm happy with what is sort of my first solar Ha image with a entry level scope - lunt 35 b400 (I had a go a couple of days ago but messed up the gamma settings with the asi120mm and didn't get very good results with my dslr so I'm sticking with the mono cam from now on).  Especially as I didn't think I'd be able to do any imaging with the lunt35.  I used my asi120mm and removed the NRs as best as I could with GIMPs Fourier transform/inverse methods (my cling film flats weren't successful and I don't have a tilt adapter yet).  It's a mosaic of two panels, 600 frames each, best 20% taken, sharpened in RS6 a bit and tweaked slightly with GIMP.  There was another panel but that refused to stack well and there was perhaps too much cloud rolling across.  At least I got the large filament.

[David Smith]

That's a good start John, well done. Definitely best to stick with the mono camera as you should get better resolution.

I would be interested to learn of your process for removing Newton rings with GIMP. I struggle with flats with my PST too and have yet to find an alternative means by which to remove this artifact.

Thanks

[Montana]

Excellent image :) we just need more sunshine so you don't run out of time

Alexandra

[laudropb]

Very good start.

[Davey-T]

Very good result from the the little Lunt John, I'm still finding flats hit and miss in AS2  sometimes they work perfectly other times they make the images worse 

Dave

[laudropb]

Very fine start. Thanks from posting.

[GreatAttractor]

It came out very well, John. The etalon tuning seems to be a bit off (surface details are not as "hairy" as they could be).

The Lunt35 is a surprisingly good performer and you'll have some fun with. For full disc I'd suggest making a mosaic of 4 shots (each centered on one of disc's quadrants); I use MS ICE for stitching and usually manage to get something like this:

Resolution isn't great, but good enough even for time-lapses of larger events:

[Joseki]

Thanks for all the encouragement and suggestions, it's good to know I should be able to improve a lot from here (yes please for more sunshine, preferably on a weekend ).   I realized I should have put this in the getting starting with imaging section but I'm more often found reading this one, so apologies for that.

That's a good start John, well done. Definitely best to stick with the mono camera as you should get better resolution.

I would be interested to learn of your process for removing Newton rings with GIMP. I struggle with flats with my PST too and have yet to find an alternative means by which to remove this artifact.

Thanks

Thanks.

anyway, my attempt at removing Newton rings with GIMP is only what I've read about on the internet.  To do it you need to install a custom plugin - "fft" http://registry.gimp.org/node/19596  this allows you to convert an image into it's fourier spectrum, edit it still within GIMP and do the inverse back to a regular image.  The Newton rings are fairly periodic so they show up in the fourier spectrum as peaks which you can remove before converting back to 'regular image'.  

i.e. 

starting with 

I then select filters/Generic/fft forward

which produces this:

without the red rings drawn on - that's where the Newton's rings spectral peaks are apparently in the image.  I then used the smudge tool to remove those peaks and selected filters/Generic/fft inverse to re-generate the image :

which is definitely an improvement.

[Montana]

Good grief! how did you know they were there? I can't see anything in the red circles 

Alexandra

[Pete Presland]

Great start keep up the good work.

[michael.h.f.wilkinson]

Very nice. I tended to make larger mosaics with the LS35, in part because I only had a DMK21 to play with. It can give great results. I prefer AutoStitch for stitching the mosaics. With 33 640x480 heavily overlapping panes I got this:

[Joseki]

Yikes, that's good! If you don't mind me asking, how do you manage such large mosaics in the day? I'm using my heq5 with only basic polar alignment (so a fair bit of drift). I've been wondering if an az goto mount & daytime 1-star alignment would make life eadier.

Anyway, I've just ordered the Rowan tilt adapter so that should help take some of the frustration out of it.