NGC 2244 (The Rossette Nebula)

[Dave_S]

NGC2244 (Rossette Nebula)

 

100mins (20x5min subs)

 

115mm APO + 0.8x reducer (f/5.6 at 644mm) and 294c ProTec camera.

 

Captured, and pre-processed with Astroart 8, and finished in Photoshop CS.

Edited February 25, 2022 by Dave_S
typo

[Dave_S]

The all important flattener back spacing!!

 

You may have noticed, at least I did, that there is a trace of Coma, towards the corners.

 

As it wasn't evident before, it made made me check the camera to flattener spacer, and it was 2.5mm out from the 55mm required (17.5mm camera body to sensor + 37.5mm of extension tubes).

 

I had taken things apart to remove some particles of dust from the flattener/reducer, and the E-Enhance filter. The flattener reducer is adjustable, and the adjustment had moved, by 2.5mm during the removal the replacement.

 

The moral of the story is, check, and don't assume. 🙂

Edited February 23, 2022 by Dave_S
typo

[paul]

You're getting some good results with that camera Dave👍

I put my spacer fine adjustment between filter wheel and the M48 rings, that way when I move the assembly between my refractor and newt the backfocus doesnt get messed up. It was nice to find that tweaking backfocus for the Field Flattener worked out for the Coma Corrector (a benefit of the 4/3rds sensor too I guess).

[Dave_S]

 I only have the one scope these days Paul, apart from the 60mm guide scope that is, so the Flattener/Reducer stays attached.

 

The rotator, and a short extension tube, stay attached to the camera, which is not left attached to the scope. 

 

A total of 37mm from the camera, plus a 0.5mm Delrin spacer ring where it attaches to the Flattener/Reducer at the scope.  This ring serves two purposes, provides the odd 0.5mm of spacing required, and prevents the two metal faces from seizing together, making for easy removal.

Edited February 24, 2022 by Dave_S
Typo