First go at Rho Ophiuchus

[rcheshire (Rowland)]

2.5 hours standing in the cold - street lights, moonlight, neighbours lights and headlights.

The technical stuff. A stack of 20 frames out of 32, approx 1.8 hours. The longest frame was 9 mins - unguided, with several at 7 mins, 6 mins, 5 mins, 4mins, 3 mins and 2 mins.

ES 80, Canon Kiss F, Takahashi EM-200B - no fringing - focus was as sharp as could be with a mask. Tracking was very good unguided, even over 9 mins.

Pixinsight - Calibrated raw files with master dark only - histogram correction, cropped to remove the dew spots (at least I think that's what they were), ACDNR noise reduction, saved file as 32 bit floating point .fit then batch converted to .jpeg

Second run alongside

The dreaded vertical stripes are difficult to get rid of.

[dugnsuz (Doug)]

Jeez Rowland, however you look at it... that's a dramatic shot. Those beautiful Antaric (!) rays really add to the shot along with the gas/dust.

9 mins unguided eh? Polar alignment must be spot on... forget it, just read that you're using a Tak mount!!!

Regardless of all technical issues, it has that 'something' that one wants from an astro-image - well done.
Doug

[rcheshire (Rowland)]

HI Doug. Thanks for the encouragement. I've posted a second run alongside the original for comparison. It's an improvement I think, and I would welcome a critique to improve my skills.

[dugnsuz (Doug)]

Originally Posted by rcheshire

HI Doug. Thanks for the encouragement. I've posted a second run alongside the original for comparison. It's an improvement I think, and I would welcome a critique to improve my skills.

I think a mid point between the 2 versions would be the sweet spot for me Rowland. The new one has lost that wonderful dustiness.

[rcheshire (Rowland)]

Here are the latest attempts. Used 31 frames this time round. Might try an HDR composite.

[dugnsuz (Doug)]

I like the 2nd one Rowland - nice contrast without losing that lovely dust.
Good exercise this - the more you play around in PS, the more you learn!
Doug

[rcheshire (Rowland)]

Reprocessed - fixed black point clipping - better balance all round - histogram attached if anyone feels inclined to comment. Some hot pixels here and there.

Backed off on the wavelet transformation and dark structure enhancement that comes with Pixinsight.

A filter should fix the stripes and or longer exposures. Looking forward to a clear dark night to try again.

Cheers.

Rowland.

[luigi]

Really nice Rowland the filtering rays to me enhance the photo, very interesting.

[rcheshire (Rowland)]

Hi Luis. It's not everyone's cup-of-tea, and I didn't really know what to expect when I took the shots.

It could be better framed - next time round. A focal reducer would increase the FOV and take in more of the unique features in that part of the sky.

[leon]

I have to qgree,very interesting image indeed, quite like it really.

Leon

[rcheshire (Rowland)]

Thanks Leon. It's a bit different. Might try an uncropped version.