I got to use it under hazy/humid conditions last night, and also gave a bunch of students from my college astronomy club their first night vision experience.
I only had the PVS-7 itself, a 6nm H-alpha filter, and a C-mount nosepiece for the PVS-7A/C (along with a C-mount-to-1.25" adapter). This very minimal setup still delivered stunning views, under moderately light polluted skies. We used it both at 1x and at prime focus inside an Orion 10" f/5 (f=1200mm) dob.
It's always a pleasure to see people experience Night Vision astronomy for the first time. Many of them were experienced amateur astronomers and were really thrilled to be able to see the North America, the California, and other famous nebula all just hanging out in the sky. Unfortunately, the 6nm filter meant that there was pretty aggressive filtering, so there was quite a bit of scintillation. If I had my 10nm I think that would have been perfect.
General impressions:
- Swan Nebula was low on the horizon and awash in skyglow, but the 6nm filter pulled it out very distinctly. It lacked some detail that I'm used to in my C11, but I think the scope needed to be collimated, and the light pollution was pretty terrible.
- Resolution seems to be very sharp. M13, unfiltered in the dob, was quite a stunner even with the collimation issues.
- Veil, Dumbbell were both very lovely and caused gasps of disbelief all around.
- North America didn't really fit within the frame at prime focus, and I didn't have my focal reducer with me.
- Crescent Nebula was not very sharp or distinct, but its general structure was easily seen.
- Heart and Soul nebula were too large to fit within the field of view, but were readily apparent.
Differences from the Mod-3:
- Lack of manual gain definitely meant we were dealing with full levels of scintillation. I had forgotten how much I use that gain knob on my Mod3.
- Bi-ocular viewing was definitely nice. Even with the scintillation, having both eyes open definitely adds.
- I think that this means that I'm going to use it for lower power, less-aggressively filtered situations. This is also where having two eyes open adds the most to the "experience", I think, because it provides an even greater sense of "immersion" under a dome filled with stars.
Comparison from my PVS-7B/D:
- I initially found that getting my eyes "aligned" with the view through the eyepieces of the A/C was more cumbersome than with my B/D unit. I still find this to be the case. However, throughout the night of viewing, I got somewhat more accustomed to it and it wasn't as big of a problem as I had initially feared.
- That being said, if I am going to use this PVS-7 more at low power and as a low-power complement to my Mod3, that also means that I will be hand-holding it more, and thus the ergonomics of how easy/hard it is to see through it will matter more. So, I'm still thinking that I will probably try to swap it for a B/D body.
One significant downside of the A/C body is that swapping out the front nosepiece is much more cumbersome than the PVS-7B/D. Unfortunately, I've found that the PVS-7A/C nosepiece adapter for C-mount has somewhat recessed threads, so my ENVIS lens doesn't seem to fit, nor do any of my SLR lens C-mount adapters. At least the 1.25" Scopestuff C-mount adapter fits. I'm not sure that the 2" would... Yet another reason to get the B/D body.