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First time with Narrowband Night Vision


DobbyX

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14/15th May 2330-0200

As a result of lockdown ennui, I bought and received my PVS-14 a few weeks ago, but only today I finally received the Rafcamera adapters to attach filters to its weird threads. My offering of a sprouting potato to the sky gods was fortunately accepted and today was blessed with clear skies.

As the lockdown has caused both TNVC and Televue to be shut meaning their eyepiece adapters have not been available, I have instead picked up quite a few bits to facilitate widefield night vision observing. Among these were a Baader 7nm Ha, 610nm LP and a 3x Afocal lens for the PVS-14. Many thanks to Alan for his clear purchasing advice, getting me started.

I had been going on short walks away from the streetlights with the bundled headmount, observing at 1x, but a) contrast hasn't been great as the sky under unfiltered NV has been pretty bright and b) the headmount is incredibly uncomfortable for me and causes bad headaches if used for more than 15 minutes. I am glad those problems are now solved.

 

NV: ACTinBlack PVS-14 with Harder Digital Gen3 WP

Bits: USGI 3x Afocal lens, Baader 7nm Ha, 610nm LP, Rafcamera ENVIS and afocal lens filter adapters

Mounts: Team Wendy EXFIL LTP helmet with Cadex Low Profile NV mount & J-arm. AZ4 mount with 1/4"-20 on dovetail.

 

First impressions

I attached the Ha filter to the PVS-14 whilst indoors, as the filter adapter ring is pretty small and the threads fiddly. I put the helmet on, attached the NV, then went outside. Once I got away from the streetlights, I flipped down the NV and turned it on, looking northeast. Immediately, I was struck by the nebulosity of the North America nebula and around Sadr (IC1318). All I could think of was: wow. I had been reading about narrowband viewing in NV for ages but none of it prepared me or detracted from experiencing it myself. I had a similar wow moment a few weeks before at first light with the unfiltered NV, but seeing the nebulae just floating in the sky, contrasted and bright without magnification, was another level. Looking around, there were lots of patches of nebulosity scattered around and I had no idea what they were. As I had not planned a list of objects, I would immediately try and go for the Veil and look things up as I went along.

3x Afocal

I couldn't immediately see the Veil at 1x, which wasn't surprising. I attached the 3x Afocal lens with Rafcamera adapter to the NV objective and looked again. It was difficult to see exactly where I was looking at, so I had to close the NV eye, find Deneb with my unaided eye, then refind in the NV and hop from there. I believe this a result of optical axis misalignment between the NV and eyes looking forward, not too noticeable at 1x but exacerbated by the 3x lens. Scanning down, the Eastern Veil popped out, clearly visible. Dwelling a bit, I picked up the patch around 52 Cyg but less obvious. At this point, I was so amazed that I had to pause and excitedly message some friends about it. I have seen the Veil a few times before, but only barely and through filtered 11-12" scopes. I had never expected that the view at only 3x would have been far clearer. Fiddling the gain up and down helped to bring out details - the image was brighter at high gain with scintillation, so it was easy to spot things, but as I turned it down, skyglow would dim but emission would remain, helping to distinguish between real and imagined nebulosity.

I panned around Cygnus and revisited NGC7000 and Sadr. IC1318 seemed to have more contrast, probably due to the more distinct dark patch within. Previously I was able to pick both out unfiltered, but the dark regions were far harder to make out. With the 7nm Ha, the dark regions looked silhouetted. The 3x Afocal lens had some vignetting, but the filter passband shift and acceptance angle meant I had to centre objects to fully view them, thus vignetting wasn't a big problem.

I looked around the northern sky in general but it is so difficult to know what you're looking at with a 3x strapped to your face, so you see these little patches of nebulosity all over and go: "Hmm. I wonder what that is".

I looked for and found the Heart and Soul nebulae, both visible clearly, but not as bright as the Cygnus nebulae.

A bright little patch next to Cassiopeia, I had to look up with some difficulty, but was found to be the Pacman Nebula. The smaller size made it stand out in NV, but identifying was tricky as DSO Planner was too cluttered to show it clearly.

Imaging attempts

I hooked up the PVS-14 to the AZ4 to try and get some pictures. They are pretty potato quality compared to some of the stunning ones others have done with NV, but were handheld for as long as I could manage (0.5-1 sec). The white phosphor gives visual views a bluish hue, which I have found to be quite natural for astro objects, the image of NGC7000 is most similar in hue to visual, although it is dimmer for the corresponding gain.

 

North America Nebula (NGC7000)

zAGsjFE.jpg

 

Sadr region (IC1318)

8eyhTYQ.jpg

 

Veil Nebula

Khz9UCL.jpg

 

Pacman Nebula (NGC281)

mrOvRTi.jpg

 

LP

I think I spent an hour and a half with the Ha. I managed to swap filters to the 610nm LP, and this made the view considerably brighter, with less sky brightness than unfiltered for an overall 'cleaner' picture. I looked around for non-emission nebulae things. By this time Leo was far enough west, and I could clearly manage two components of the Leo Triplet at 3x. Again I had a go at M51 and M101, and again both were visible, but much better contrasted than unfiltered. M81/M82 were also distinct at 3x. Many of the nebulae that were earlier just floating around were simply not visible without the narrowband, washed out by the sky. The Milky Way starfield at 3x was very rich, and I did not try to identify particular objects.

Unfortunately as the main road and streetlights are directly south, I could not observe many fun things. I hope to rectify this as soon as possible, especially with the upcoming summer objects.

Thoughts

Night vision has given me a complete refresh of the hobby. Being able to see so much with so little kit is a very welcome addition. It also makes me keen to take the heavy C11 outside, before and especially after adapters become available again. I had previously tried EAA with a Revolution Imager a few years ago, and I found it too fiddly for not significant value added, so I stuck to purely visual observing. The addition of NV to visual adds fresh perspective and motivation to once again revisit the frequented objects that became satiated, which I am eagerly going to try.

On the practicalities of 1x/3x/5x widefield NV observing, I have found the helmet mount to be an excellent method. Eye relief and alignment can be adjusted, and held there. In addition, I found I can hold my head steadier than my arms, and my particular mount is solid with negligible wobble. Properly counterweighted, it is a very comfortable observing experience overall. I am preferring the helmet mount to an altaz, due to the latter's change in eye position with slewing, and can be uncomfortably low at high altitudes. However, I must consider investing in a sun lounger to reduce neck strain whilst looking at things near the zenith.

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  • 1 month later...

Apologies for missing your post… we don’t many NV posts on SGL.

Welcome to the dark side, sounds like you’ve got all the right bits and have got some good views… the best areas are starting to come back again in the late evening.

You might like to get a copy of  Bracken- astrophotographers star atlas, it’ll show you what’s about nebulae wise.

You’ll find that red stars make star hopping a pain, around the milkyway you’ll probably end up Nebula hopping once you’ve seen got your bearings.

 

I use a 685nm filter for non-nebulae and use it for starfields, clusters and galaxies (I can see plenty in the 8”, though they’re rather tiny)…. More than I could expect normally given my light pollution. You’ll spot lots of satellites (more now Mr Musk is in the game) and meteors.

For phone imaging and C11 usage @Gavster is the local expert. He’s just got Televues new “ lens” to make stuff even faster… expect a post quite soon.

 

I’ve always wondered what a helmet mount might might be like..  details please? For zenith observing I’ve always found lying on the ground with a pillow under my head to be the most comfortable, not good if wet or if there is a risk of others tripping over you.

 

As the summer progresses, there’ll be a lot more to see along the milkyway from Cepheus to Sagittarius. Do post more of your experiences, be good to see how many more people we can show the benefits to!

 

Peter

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I completely missed this too. An excellent account of what sounds like a successful evening.
Night vision revolutionised astronomy for me - accounts for 95% of my dso observing now. And 18 months since getting my PVS-14, I’m still blown away by the views. Last night for example, midsummer’s night from the centre of London, I had memorable views of M3, M13 and M92, using Delite 18.2 through Epsilon 130. 
Great to have another NV enthusiast on board - welcome to the club!

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