ASTRO: Sh2-261

Sh2-261 is am impressive emission nebula in northern Orion, not far from the
often imaged NGC 2174/2175. It is much fainter than it's famous
brother/sister, but still has a good surface brighness, so it is amazing
that I have not imaged it before.
I imaged it in three nights but ended up using only one night's data as
conditions had been bad in two of the three nights. There was only a diffuse
weak brightening in the middle of the nebula in OIII and SII was the same as
Ha, only weaker. I ended up doing a Ha:SII:SII.

Taken from Berlin with a Celestron RASA at f/2.2, G11 mount, Trius SX694
camera, 57x3min Ha and 34x3min SII.

Stefan

Originally Posted by Stefan Lilge

Sh2-261 is am impressive emission nebula in northern Orion, not far from the
often imaged NGC 2174/2175.
Stefan

How do you handle filters. Remove the camera for a screw in filter or use a filter drawer?

When I did filters in film work either way I was always fighting dust. In the farm field I worked in it was everywhere and no matter how careful I was it got on the filters. Drawer had the advantage the camera orientation was held steady. Even with a bayonet mounting I had issues with it rotating slightly with filter changes. Using a classic dark room rather than digital this made aligning the colors "interesting". This was in the 80's before digital had replaced the dark room.

Rick

Rick,

sorry for the late answer: I use a filter drawer with the RASA.
Actually dust is not a problem with such a fast scope, dust donuts are so
large and fuzzy that they are not really conspicuous (unlike my Meade ACF at
f/8, where they are very obvious).

Stefan


"WA0CKY" schrieb im Newsbeitrag ...


Stefan Lilge;1310107 Wrote:
Sh2-261 is am impressive emission nebula in northern Orion, not far from
the
often imaged NGC 2174/2175.
Stefan

How do you handle filters. Remove the camera for a screw in filter or
use a filter drawer?

When I did filters in film work either way I was always fighting dust.
In the farm field I worked in it was everywhere and no matter how
careful I was it got on the filters. Drawer had the advantage the
camera orientation was held steady. Even with a bayonet mounting I had
issues with it rotating slightly with filter changes. Using a classic
dark room rather than digital this made aligning the colors
"interesting". This was in the 80's before digital had replaced the
dark room.

Rick


--
WA0CKY