The Rosette

[Pete]

Thursday, 4 Mar 2021

There’s a strong wind tonight but there’s a break in the weather so I’m out doing a systematic evaluation of the Hyperstar, testing backfocus rangng in 1mm increments around Starizona’s published value. This work occupied time from 18:00 – 20:45 hrs, but the wind has dropped to 20mph and the sky’s very transparent and clear. Why waste it?

NGC2244 – the Rosette Nebula

NGC2244 15X3M 120G -20C annotated.jpg (6.17 MiB) Viewed 998 times

15 X 3 min, 120g, -20C, 3 Hz guiding

This image was taken without flats but the nature of the Rosette is such that vignetting doesn’t show. The optimal backfocus is used here and the stars are pinpoint. Happy days.

Conclusions & lessons learned:

Not bad for a 45 minute image.

[menardre]

Pete
That is an absolutely stunning image of the Rosette Nebula. You really have figured out your system and are producing great images.

Keep it up.

I imaged IC 417 last night with my IDAS filter. I have not finished processing yet but did notice stars are not pinpoint - mostly due to wind gusts all night. My scope is pretty much open to the night sky so wind can be an issue, even if I use wind shield barriers.

Roger

[Pete]

Thank you Roger. Been tweaking the Hyperstar for 2 months now. Tonight I was out running more backfocus tests and stars were even tighter after moving the camera in an additional 0.012" Starizona says that backfocus is critical to ±0.002" and that seems to be the case, crazy as it sounds.

Plan to put my kluge adapter aside and have a larger diameter unit fabricated to reduce vignetting now that the backfocus has been nailed down. Think I'm getting spoiled by this amazingly fast optic. Which is a good thing as I don't have the patience that everybody else has to capture photons for hours and hours.

[Bruce D]

Pete like Roger said! That is a beauty!