I had the best night so far. What so nice about the PVS7:
1. the correct view in the dob. Matches my RACI Finder.
2. Dark adaptation not critical. I need a bright red light to read my charts. This affects my adaptation for visual observing. With the PVS7 not a problem. I have more trouble using the 60mm finder after consulting the chart.
3. Two eyes view. Would not be interested in monoviewing.
4. The H-a clouds if nothing else
I dont know know the specs of my tube. I'm very satisfied with it. I told NAIT I wanted it for astronomy. I don't know how this affected the tube selection. They did good regardless.
Oct 8 2015
Observing at home.
Clear and cool conditions. Mag 4 skies, Milky Way invisible. Lots of glow from the city and shopping centers. Trees limit my scope view to overhead.
PVS7 with Canon FD 85mm f/1.8 lens and Olympus red filter. 30+ year old camera equipment.
Able to view Milky Way clouds in Aquila and Scutum. Able to make out very faint Gamma Cygni nebula and North American. Lots of stars. Lyra constellation shape distorted by brightness of XY and 13 Lyr. In Cepheus, VV is just as bright as Delta.
With 18" Dob
I was able to use the .5x focal reducer by moving the mirror up a little. Lots of coma except in the center 1/4 FOV. Nice widefield views of H-a clouds. The filter works at f/1.2 with the stock PVS7 lens, and works fine at f/1.75.
Conclusion: The focal reducer gives a wider field, but too much detail lost due to coma smearing. This is verified by examining the "leopard spotting" of the Crescent Nebula. It's good for the larger tenuous clouds.
Egg Nebula - nice view with LNS (Lumicon Night Sky filter) Improved view with 2x Barlow . No improvement with H-a.
NGC 7048 - Invisible with no filter, barely seen with LNS (Would not be seen if I didn't know where to look) Nice round transparent disk obvious with H-a
Open Clusters Basel 12 and 13 - Very weak, looks like background (LNS)
Open Cluster NGC 7039 - Nice thick concentration. Large. Not well detached from rich Milky Way background.
PN NGC 7026 - nice little hamburger with LNS. A little more definition on outer envelope with H-a. Good with 2x Barlow.
PN 7027 - nice unfiltered view with 2x Barlow. Has 3 slightly unequal lobes.
PN Sharpless 1-89 Invisible with LNS. Faintly visible with H-a. Difficult round ghostly disk.
PN NGC 7008 - very faint with superimposed stars without filter. Some improvement in visibility with LNS. Nice oblong ghost, irregular brightness with H-a
IC 63 Gamma Cass nebula - fainly seen with H-a. IC 59 not seen
Sharpless 2-88 Nice fat crescent as drawn by a coarse brush with H-a. Invisible with LNS.
Stephens Quintet - couple of tiny smudges unfiltered. All 5 seen with 2x Barlow.
NGC 7331 - Lovely!!! like a tiny M31, or M104. NGC 7327 and 7340 in FOV.
PN NGC 7662 - bright unfiltered view, nice detail within spherical outline. 2x Barlow - bright figure-8 in elliptical envelope. With LNS - dimmed, but increased detail. H-a : no difference, but detail lost to dimming.
PN IC 2149 - Unfiltered view: star with faint oval envelope. LNS: envelope lost but still non-stellar with soft appearance. H-a : solid tiny oval. Best view: 2x unfiltered.