Where night vision tech works and where it doesn’t

[GavStar]

After using my night vision monoculars around 7 or 8 times it’s become clear that on some objects it makes a massive difference and on others it’s not helpful at all. 

I read an interesting post today on CN where an experienced user breaks the benefits of NV down by objects as follows. (It does broadly follow my experience to date)

Category 1

NV reveals things invisible / impossible with normal scopes (Hydrogen Alpha nebulae,  infrared stars, methane band planetary features ) 

Cat 2

NV reveals sights beyond current aperture, and/ or difficult in large apertures  ( faint galaxies, quasars, clusters, faint doubles,  dust lanes in core of NGC 253) 

Cat 3

NV improves view of common objects comparable to using the same scope under dark skies. Under dark skies like using 2-3x aperture, target and viewer dependent of course. (Dust lane in NGC 891, viewing Leo Trio in urban skies with direct, not averted vision, dust lanes in M31) 

Cat 4

No or minimal improvement over visual. (Dust lanes in M31) Why the overlap with the previous category? This is where NV tracks evenly with visual, so other visibility factors take precedence (transparency, Sky darkness, humidity, visual acuity) 

Category 5 

NV inferior to visual. 

Reflection  nebulae: blue color out of NV passband

Dark Nebulae in Milky Way : the NV shows faint stars normally invisible in these, so the contrast between the nebula and starry background is lost

Close doubles: star images are larger with NV, so close companions are covered by the electronic halo

Colorful stars: take a guess why

Planets: too bright for NV without heavy filtering, in which case detail is lost

[John]

Interesting Gavin

It's good to understand as much as possible what it's good for and where it's not so useful. Helps inform the choice on whether to invest or not.

 

[scarp15]

Good insight into this system, speaking with others and reading up, it may well benefit some larger faint nebulae types.

[Highburymark]

I saw that too Gavin. I can imagine that open clusters would also be more satisfying through a conventional telescope. Even if it can go much deeper, could a night vision device ever rival the beauty of the Plaiedes through a decent refractor? Having said that, the list of targets improved by NV is pretty mouth watering. 

Have been doing a bit more digging on gear - there do seem to be a couple of UK outlets now selling Gen 3 devices. Canadian made. Slightly cheaper than on Continent. But as you said Photonis 4G tube does seem to be the best option.

[GavStar]

I think you’re right on open clusters Mark. Although you see many more stars with NV you don’t get the pure crisp star shapes that you get without. Also there are so many stars shown that for example on the double cluster, the two clusters don’t ‘pop’ out as much so I think the aesthetics are not as nice.

I’ve only had a quick look at a couple of globulars, m5 and m92 - on the initial look in an LP site, I much preferred NV as it made the globulars really resolve.

Regarding UK suppliers, I tried to contact a couple that said they sold gen 3 Canadian made pvs-14 but they never responded so I gave up.

i saw a review of actinblack and they looked impressive- actually making the bodies that hold the tubes themselves. They were also the only supplier I could find in Europe of photonis tubes (which I think are recognised as the best European tube maker), Actinblack were very helpful - I spoke to them several times and they were happy to email me the actual spec sheets for the tubes they had in stock. Very quick delivery as well.

Actinblack also sell German gen 3 tubes by harder digital. However they only had green tubes in this make and harder are not as well known (from my research harder digital acquired a Serbian maker of vision tubes and I think this is where their tech comes from).

[Highburymark]

Didn't realise 'harder' tubes were green only - white looks so much nicer for astronomy. Everything you write reinforces your choice of equipment and retailer - as long as access to Gen 3 devices remains so restricted in Europe.

[GavStar]

Mark, Actinblack told me that harder do make white tubes but that there would be none available for at least six months. They steered me towards photonis tubes despite some of the harder tubes having better specs on paper.

I have looked through a green tube and I found the colour a bit off putting - imo it looked artificial. I took a risk ordering a white tube without having any direct experience but I’m very pleased I did. With the gain turned down to around half, i love the natural clear look. Manual gain is important to get I think.

[PeterW]

Dark nebulae :-( no wonder I have yet to nail Barnards E. For small scopes the NV improves globs, but personally ruins the view through a BiG scope. The effect on galaxies depends on the spectrum of the galaxy and the tube response, old orange red stars or blue star birth regions. M82 works well as do some others, other galaxies is no improvement. 

There is always the secondhand market... but then you get no specs.

PEterW