Trifid in Ha

[alistairsam]

It's been a few months since I imaged so thought I'd do a quickie on the trifid to test out my ota upgrades

I will be adding O3 and SII for a tricolor

This is 4 x 20 mins 5nm astrodon Ha

STF8300m
Paramount MyT
10inch F4
Processed in startools

Full res.
http://www.astrobin.com/full/247692/B/


Alistair

[Peter Ward]

Nicely done! :thumbsup:

(working on M20 myself...with spotty results to date)

[Atmos]

Looking like the beginning of a great image! With more subs you'll get food rejection on all of those hot pixels :)

[alistairsam]

Hot pixels? really? hmm I did run a rejection filter as my dither didn't work but I didn't notice any. chip was -23C and these were calibrated against darks.

I did a compare with Steve's trifid, mine's on the left in the attached screen shot. do you still think there are hot pixels??
I'll pay more attention when I get more data and will get that dither working

Steve's pic - https://www.flickr.com/photos/105968790@N03/18136336765

Cheers
Alistair

[glend]

What causes the diffraction spikes to turn into a string of dots? Beautiful otherwise but i find the lines of dots distracting.

[Atmos]

See those little black spots in this crop? They're scattered all over your image. To get rid of these you just need more subs, four isn't really enough to get a good and clean rejection going.

I used to have a QHY9 which has the same KAF-8300 sensor as your SBIG. It is a great sensor but even at -25°C is it kinda noisy. Some more subs will smooth all of those little dots :) With enough subs and dithering you don't even need to worry about darks with the KAF sensors.

Glen, I think it's caused by the Ha filter, I notice the same thing in my refractor when I am focusing on mag 3-4 stars with my bahtinov mask.

[alistairsam]

Hi that's my dual vane spider. I don't mind it, it's either that or large spikes on bright stars which I don't like. It sort of disappears when other channels are blended in



Thanks I get it. That's a result of improper calibration. I'll redo it again when I add more data and it shouldn't show up even with less data

Cheers
Alistair

[Placidus]

Very fine detail already. The main Herbig-Haro jet is very clear, excellent in fact, as is the dusty evaporative gaseous globule next to it. The double star in the centre is resolved into four, and the brightest of the four (itself a close double) is elongated.

Looking forward to the tricolour version. (You might need more subs when it comes to SII)

Nice capture.

[RickS]

Nice level of detail, Al. The HH jets are always a good test on this target.



It's a normal diffraction pattern for a spider and narrowband filter. You see the same effect in R/G/B data but more smeared out by the larger bandwidth. My Ceravolo 300 produces pretty rainbow coloured spikes in RGB images.

Cheers,
Rick.

[glend]

Thanks Rick, I am doing narrowband through my Mak-Newt so no vanes to produce those patterns. Must try through my regular newt and check it out.

[Andy01]

Looks good Al, you're certainly the king of short integration time images. Great detail for only 4 subs!
Seems to be a bit of coma on the left hand side maybe?
Good to see you imaging again :)

[alistairsam]

Thanks for the info, had to look up all that, very interesting. There's a lot happening in there. I was stoked that the HH was clear in the raw sub with no processing.



Thanks Rick, yep I always look for that jet, didn't realize there's a stalk "EGG" protrusion next to it which I've managed to capture as well.




Thanks Andy, I think its in my genes to have short integration, need more discipline in setting up early!! The speed of the F4 certainly helps.
yep that's elongation is due to collimation, i'll be fixing that.

Cheers
Alistair

[rustigsmed]

hi Alistair,

I thought I had commented on this, but definitely a great start! I think the antennae are in there, it is quite deep for 4 subs! and the main neb fairly bright. looking forward to more! :thumbsup:
will you also be grabbing some RGB? always looks nice in LHaRGB

Russ

[SimmoW]

Very, very impressive start Al! Can't wait to see this one finished - before the election?

[codemonkey]

Looking good so far!

[deeplook]

This one is looking very good Alistair - especially because I like b&w imgaes very much. But - I'm also looking forward to the narrowband version!

Markus

[Ryderscope]

Nice one Alistair. The Ha version makes it look a little 3D and is heading towards the viewer.

[strongmanmike]

Ha..thought I had already commented on this one Alistair :question:..know I started writing a response..must have got distracted :screwy:

Anyway, a great start, some really good res and the field is looking deep too.

I get multi-coloured diffraction spikes (https://www.flickr.com/photos/strongman/22248564732/in/photostream/)too, I like'em :thumbsup:

Mike