Rosette Nebula

[jetstream]

A quick note from a rewarding evening. The sky was avg in transparency and dark, 21.4 ish and the 200mm VX was used with 3 eyepieces- 30ES 82/21E/Zeiss 25.1-6.7 zoom and a UHC as well.

More filterless nebula practise led to the Rosette nebula again and I thought I would share what to look for as it is quite distinct. Just under the cluster of stars (dob view) there is an almost featureless oblongish grey patch, which is notable for the lack of stars in it. When searching I would look for this starless area first and then try to catch the edges. A UHC or OIII can be used to check your findings by placing it over the eyelens. Tonight I found the nebs no problem at all and with the narrow Zeiss zoom and no filter- including a section of Barnards Loop (30 ES 82/21E)

It is very helpful to practise this filterless viewing to prepare for the really faint stuff and also to enhance optimal viewing with a filter.

Large exit pupils help.

[michael.h.f.wilkinson]

Interesting report. I have observed filterless for years, and detected quite a few faint ones, very often by looking out for dark areas indicating a dust lane or blob blocking light from something behind it. SInce I got my UHC and O-III filters, I note that many of these faint emission nebulae are much easier with the filter (in particular UHC). I have a filter-switch diagonal from Denkmeier, and that allows rapid switching between filterless viewing and one of two filters in the filter slide, so the effect is easy to see. The effect certainly depends on the degree of LP. In moderate LP the effect is unmistakable, but even in very light LP the UHC helps. I was once in the Haut Provence near Olly's place, and the contrast in the North America Nebula and especially Pelican was clearly enhanced by the UHC filter, and there was hardly any LP there.  For reflection nebulae the filters don't work, of course.

[jetstream]

I agree Michael, the filtered look of the North American can be stunning with a few "layers" of outer nebulosity showing nicely. My 15" has a filter slide and I truly wish I could make one work on this 200mm. In my opinion the switches should be available for any scope.

In my case I'm trying to get better detection skills to use for some faint nebula (reflection mainly) and I find practising on the mentioned objects and others help. M78 and its companion are hurt pretty bad by the UHC.

[Helix]

7 hours ago, jetstream said:

In my case I'm trying to get better detection skills to use for some faint nebula (reflection mainly) and I find practising on the mentioned objects and others help

I completely agree on this one, Gerry. It helps me to train my eyes detecting faint nebulosity without filters. I noticed that I can see some really faint stuff now, including background nebulosity. I also like pure unfiltered views at times, especially in low power.