TL;DR: Had an amazing romp through the summer sky last night, am now wondering if I should get a smaller scope, and/or how to build up the perfect NV system for hand-held and tripod-mounted sky-scanning.
I've only had my NV goggles for a month or two, and this weekend I'm at my in-laws' house about 40 minutes outside of town. Their skies are dark, but there is a high school and its giant football stadium adjacent to their property. Its lights and the HS parking lot lights are on all the time (yay, Texas!), but I fortunately have some trees on the property to block most of them.
Last night I had an amazing experience with my night vision goggles, because I obtained the 3x objective, and because I had proper time to try out various filters. I bought the 680nm IR filter off ebay, which kinda fits inside the front of the 3x objective. I also had a Lumicon deep sky filter. And to really enhance nebulas, I have the Orion narrowband Ha filter.
Last night, when I first scanned the sky with the PVS-7s, it was the normal lovely "sky full of stars" effect. However, when I hand-held the IR filter in front of the normal (1x) objective, I could immediately see the Milky Way, complete with dust bands, stretching from Sagittarius up through Cygnus and towards Cassiopeia. It was marvelous. The glare and glow from the nearby football stadium were practically gone. When I looked again without the filter, the entire sky looked "washed out", even though it was filled with so many twinkling stars.
Next, I hand-held the Lumicon Deep Sky filter in front of the 1x objective, and it was just as effective as the ebay IR filter for cutting out light pollution, but the nebulae in Sagittarius popped a lot more. I could plainly see the Lagoon nebula and the whole string of nebulae near it.
Next up, I used the 3X objective and the Lumicon filter to zoom in on these regions. Sadly, the 2" filter does not fit snugly inside the front, so it was a fairly sketchy proposition to hand-hold it. This is not hard to do, but it is one point of stress that distracts from the observing process. However, the views are well worth it. I just got lost studying the structure and texture around the center of the galaxy.
Finally, I tried out the Orion H-a filter. Since this is a 1.25" filter, it just barely fits inside the front of the 1x objective of the PVS-7 unit. Once again, however, just as with the Lumicon in the 3x objective, this is not a "fit" in any real sense of the word, so I had to use one hand to gingerly hold the filter in place while viewing.
But one look at the sky in amplified H-alpha changed my mind about modern visual astronomy. I visually observed the North America Nebula at 1x, and the entire region around Gamma Cygni was aglow. I saw the Garnet Star Nebula just hanging there. The string of nebulae stretching up through Sagittarius were like little puffy clouds in the sky. You couldn't not notice all of the stuff out there. No squinting required, no averted vision. I've never been able to see the skies like this. I remember being out at Island Pond, VT years and years ago, under exceptionally dark skies, and I couldn't see the Milky Way like the way I did last night, through football stadium skyglow.
When I put the 3x afocal objective on the front of the lens (and thereby enclosing the 1.25" H-a filter), it was just another world. I couldn't stop sweeping through Cygnus. The Lagoon and nearby nebulae also easily came into view and were lovely. I'm attaching some photos I took hand-held through one of the sides of the night vision goggles. They just do not do the experience justice. (But, keep in mind I'm holding a combined PVS-7 unit + 3x objective in one hand, while lining up an iPhone with the other hand, all while craning my neck up towards the sky!)
The upshot of all this is to say that I'm rethinking how I approach astronomy, given my current life parameters. I am extremely busy with work and the kids. I live inside a big town. The weather is fairly good in Texas, so there are quite a few nights of potentially good seeing. But getting out to non-totally-light-polluted-skies is a 20 minute affair at best. I'm wondering if I shouldn't downsize from the fork-mount C-11 to a fat, fast APO on an EQ. It would be a much more portable setup, and furthermore, I want to optimize for having WIDE views of the Milky Way that I can plug my Night Vision gear into. The C-11 EdgeHD is an amazing optical instrument and I've truly enjoyed my views through it, but it is a very bulky setup. Additionally, when I use my NV gear with it, it's too zoomed in; and for realtime video/EAA purposes, the f ratio is just too slow, without fiddling around with a bunch of reducer gear in the dark.
Stated differently, I originally got the C11 basically out of optimizing for aperture - because, heck, why not? That was before I discovered EAA and NV. Now, I'm realizing that I need to optimize for "good photons/cm^2", via f-ratio and SNR, as well as "total flux integrated/month", based on how often I'm able to get out and look at stuff. Those do not necessarily put the C11 on the efficient frontier...
So, I'm kind of interested in brainstorming about the "ideal setup" for NV-intensive astronomy. That is, I want to have sharp, unaided visual observation of clusters, planets, etc. But I want a setup that is easy and portable and fun to use for just sweeping the sky, looking at stuff.
Honestly, I think if I had a filter wheel for the front of the PVS-7, a 1x-4x or 1x-5x zoom, and a tripod mount, that would basically be the ticket. If I also could get that in a high-quality APO that I could also use for realtime video, that would be the ultimate.
Thanks so much to the folks here at CN that have provided resources and information that have helped me acquire the right tools to enjoy the night sky like I did last night (and special props to Eddgie! :-)