RE: (IAAC) Object: M45, Instrument: 16" Newtonian f/4.59
>>Darker skies should help in seeing the nebulousity surrounding M-45. I
>>have seen it in my old 6.8" f/14 AP refractor under very dark skies
>>(est. limiting mag. 6), and it was easy in my 20" Obsession both with
>>and without a filter under reasonably dark skies (est. limiting mag.
>I rarely find that the DeepSky (or other broadband) filter helps with
>reflection nebulae or galaxies (continuous-spectrum objects). There are
>certain conditions (like a hazy night under a VERY dark sky, or a very
>transparent night under a very light-polluted sky) where paradoxically the
>DS WILL make a difference, though. Have others had the same experience?
>Anyway, the observing sessions I cited where the Merope nebulosity was
>visible were all WITHOUT the use of any filter... Not that a DeepSky
>mightn't have improved the view those nights even more: I just didn't
>happen to think of trying it out at the time!
Hi Todd and Lew:
The night I picked up the reflection nebula around M-45 with the 6.8"
f/14 refreactor I was not using a filter. With the 20" I could see it
both with and without a DS filter. In Mallas and Kramer's book "The
Messier Album" I believe Mallas has a drawing he made using a 4" f/15
Unitron refractor showing the nebulousity around at least some of the
brighter stars. I beleive he observed from dark skies in Arizona .