Petergoodhew

54 minutes ago, Laurin Dave said:

Very nice Peter..  like the faint fuzzy which looks remarkably Saturn-ish .  Is that with the twin TECs? 

Dave

Thanks Laurin - yes this was with the twin TMBs.  Now with the dual rig I can capture Ha/OIII twice as quickly!

Peter

1 hour ago, gorann said:

Great image of an amazing sphere Peter!

My only minor critisism regards the violet halos around many of the stars (on my screen at least) - not sure what colour they should be (white, blue or red) but probably not violet (at least not that many of them). PI has some new routine for calibrating star colour but I have never tried it.

Göran, yes the colour balance needed adjusting.  Too much magenta lurking around!  Fixed now. Many thanks, Peter

Abell 39 is a low surface brightness planetary nebula in the constellation of Hercules. It is almost perfectly spherical and also one of the largest known spheres with a radius of about 2.5 light-years.

22h5m total integration (20x300s L,13x300s R, 20x300sB, 20x300s G, 32x1800s OIII).

e-Eye, Spain 28/3-4/5/2019.

APM TMB 152 F8 LZOS, 10 Micron GM2000HPS, QSI6120wsg8

It's a lovely image.  I'm struggling to see the star elongation too. One possible explanation for it could be wind conditions, given the long OTA of a 150 refractor, increased exposure from the higher elevation, and high sensitivity resulting from being F11.

Personally I would like to see a little more red, so would add the Ha to 1.0 R rather than 0.9 R.

Yes the colours are unconventional - but you've achieved a staggering amount of depth - I don't think I've seen any astro image with so much 3-dimensional feel to it.  A remarkable and beautiful image - even if the colours take us out of our comfort zones!  Smashing!

I've been really struggling with star reduction techniques messing up the stars. Have just tried this and it works a treat!  Many thanks.