NV meets a Genesis and a Mewlon with a learner driver in charge!

[Stu]

A very generous gentleman on the forum (I’m sure you can guess who) has leant me his Photonis NV monocular to try for a little while. Fortunately I have had a couple of clear nights this week and the opportunity to give it a spin, so, here is my report on what happened and my thoughts so far.

The Kit I have borrowed consists of the Photonis NV monocular, a 55mm Plossl, a 32mm Plossl, an adaptor to connect the monocular to the eyepieces and one to connect 2” filters to the monocular for x1 viewing. Finally, there are two Astronomik filters, an Ha 6nm for viewing nebulae and a 642nm ProPlanet for viewing galaxies.

The main intention was to try this with my Televue Genesis which is a 100mm, f5 scope with a flat field of view. In theory, very good for NV as it is fast. I also wanted to try x1 observing just handheld for scanning the skies, and also then considered using the Mewlon 210 for galaxies and clusters. Over a couple of nights this week I’ve achieved all three of these objectives, so here goes.

On Sunday 24th March, I used the NV handheld at x1 with the 6nm filter in place. Orion was pretty low by this time, but I saw M42 albeit not very impressively. Moving on, the Rosette was clear, bright and quite large. From there I moved along the bottom of Gemini, and found a small bright patch of nebulosity which turned out to be the Monkeyhead nebula, I had never really known where it was before, and certainly hadn’t seen it visually. Scanning through Auriga, I noticed a patch of nebulosity with some form of structure to it. Again, I didn’t know at the time but it was the Flaming Star Nebula, another than I had not seen before. Next up, the California Nebula. This one was bright with an obvious elongated shape, one of the better targets. Finally, the Heart and Soul nebulae. This is in a bad area of sky for me at the moment but still I managed to detect both of these nebulae. So, overall a good start. Targets that I just never see from home, or even have never seen before became quite obvious.

Monday night, 25th, I negotiated a couple of hours observing between 8 and 10pm with SWMBO because we both had early starts in the morning. I got the GP-DX up and running with Skysafari early on with the Mewlon on top, but must have messed up the alignment because the Gotos were way off. M42 looked ok, but the scope was still showing quite bad tube currents, so I decided to switch to the Genesis and get going with the main event; nebulae hunting. I had to quickly change the dovetail on the Genesis because it would not fit on the new, longer ADM dual saddle I fitted recently. Once fixed, a fresh alignment sorted the gotos and for the rest of the night they were very accurate, although it needed a quick re-align after I switched to the Mewlon.

The skies were clear, but the transparency was only average I would say. I was too occupied with working out what I was doing with this unfamiliar kit to take an SQL measure or even assess the NELM, but normally my skies are mag 19.1 at best, around mag 5 NELM. I suspect it was a little less than that last night. The Genesis was theoretically giving around 4.4 degrees field of view, but in reality it felt like 4 degrees max, possibly a little less.

My first target was the Rosette, and I will confess to being a little disappointed with the view. It was more like a poorly defined oval with a central hole than anything defined. In hindsight I think this was down to sky brightness – it was still not Astronomical twilight when I started observing, and also dark adaptation. This is a controversial point which I will address with my thoughts at the end of this post. Later on I returned to the Rosette and it was much better, even though it was lower in the sky. Clear structure to it and much better definition. The darker central hole sparkling with the stars of the embedded cluster.

I moved on to the California Nebula, NGC 1499. This was better straight away; the long axis very nearly filled the field of view, and I could see both the overall shape, plus the brighter edges and slightly darker inner regions. I viewed this one several times over the course of 2 hours, and it generally got better each time, more definition and detail visible.

The Flaming Star nebula was a disappointment. Very poorly defined, although I did also identify IC417 nearby which stood out quite clearly. The Monkeyhead was a good one, the shape was clearly identifiable, and I got hints of the internal structure which made the ‘monkey’ association clearer. Onto the Heart & Soul nebula next. The Soul, I found quite soulless… ? Not much definition, just a sort of squared off long oval shape, if that makes sense. The Heart on the other hand was much more interesting. I could follow the loop of nebulosity dropping down from beside the embedded star cluster, and also hints of the ‘arm’ stretching out. Bearing in mind these two were in my worst direction, towards London and Heathrow I was surprised to see anything. Lastly with the Genesis, I went for the Pacman Nebula which I enjoyed. Clear shape, with the Pacman mouth plain to see.

Actually, lastly was incorrect, I noticed just before I took the Genesis off the mount that Orion had cleared the annoying (but very nice) tree which blocks the view of Orion at a certain time and was still visible above the neighbour’s house. Not expecting  anything, I tapped IC434 on Skysafari and sent the scope off to find it, which it did, bang on. The Flame Nebula, NGC 2024 was immediately obvious, with the central lane well defined. There wasn’t much more detail to be seen to be honest, but it was reasonably bright, particularly given the transparency and altitude. IC434 was visible more faintly, and initially I didn’t think I was going to be able to see my prize! However, with some averted vision, and flicking my eye from the target away, I was able to see the notch in the nebula that was the HorseHead Nebula. It wasn’t obvious, or always there, but reference to Skysafari showed that the object I was detecting was in exactly the right place, so I will put that down as a win! The Horsey from a suburban sky with a 20 year old 4” scope and a bit (lot) of help from technology, not too bad!

I’m hoping to get a chance under better conditions, as I think the nebulae will show better with improved transparency. It will be interesting to put the Genesis side by side with Gavin’s Baader 95mm (ooops, gave it away) to see which gives best results. I’m hoping the veteran Genesis will at least give a good account of itself next to the young pup Baader.

Time to switch to the Mewlon for some Galaxies and clusters.  The Goto drifted a little after the switch, but I aligned on nearby bright stars with Skysafari to get it back on track.

The Leo Triplet didn’t quite fit in the field of view which I would estimate at around 0.7 degrees. I guess I would say this was an nice view, but not overwhelming. M65 and M66 were there, had shape and showed in their correct orientation. NGC 3628 was visible, although much fainter. I’ve seen better views in a large dob under dark skies, but this was a 4” scope under poor skies, so I can’t really complain! These targets are all but invisible in this sized scope from here normally.

The Whirlpool Galaxy showed as two bright cores, little or no halo detected. I did a whirl (?) around a few more galaxies; M95 & M96, M83 and M106. All were clear visible as galaxies but with little to see other than their basic shape. More rewarding were Bode’s and the Cigar Galaxy. Bode’s showed as a bright core and the faint oval shape of the spiral arms (no spirals visible though obviously). The Cigar Galaxy was great, lovely elongated shape, and dark mottled structure in the centre. A really nice view, the best galaxy of the evening.

Finally on the Galaxies I went for the Needle. This showed clearly as the core, with it’s fine needle like arms extending from it. They showed better with averted vision, growing in length each time I moved my eye away.

Last stop were the clusters which turned out to be great targets for this combination of Scope and NV. The Double Cluster was fabulous. Lacking the fine pin point stars that you get visually normally, but made up for with the sheer number and brightness. I couldn’t quite fit both in comfortably at once, but taking each on its own was more than enough. M44 was too big for this combo really, but M67 was ideal, resolving clearly in a fine, small cluster. Lovely one.

M36, M7 & M38 all benefited from the NV, showing far more stars and with more definition than visually. Each has its own character, very different and they show the variety that you can get with what are apparently similar sized cluster.

And finally, as Mr McDonald used to say…. M3. A great way to finish. Bright and resolved to the core, it would have benefited from some addition mag but I could not face changing eyepieces at that point so that is one for another night. It seems that globs respond well to NV too, so definitely worth trying for more of these.

I wish I had had the time to move on to the Virgo cluster of galaxies, and hope to be able to do that at some point before this lovely kit has to go back home!

So, my thoughts?

I very much enjoyed using the NV gear in both scopes. Very different setups giving good results on different targets. Fast scope for the faint nebulae, and larger aperture for the galaxies and clusters. Despite being electronic in nature, using NV feels very natural and does not necessarily serve objects up to you on a plate. You still have to put some effort in to get the best out of the kit.

Two questions….

Do you need to be dark adapted to get the best out of NV?

In my short experience yes, some level of dark adaptation is required because looking at my phone on even on half brightness still significantly reduced the amount of detail I could see afterwards. Setting my phone to low brightness and red really helped. The NV display is not that bright, so I think you have to adapt enough to maximise what you can see. The precise biological mechanism in this instance I have no idea about! In my view using NV does affect your night vision though for really faint objects so I would tend to stay clear of mixing NV and traditional visual astronomy in the same session if you want to see the most visually.

Is AV useful for NV viewing?

Again, I would say yes to this. Specifically for the Horsehead and the Needle Galaxy, AV was a clear benefit to detecting the Horsey and seeing the further extension of the galaxy's arms. Like dark adaptation, I am unclear of the mechanism at work, but it does seem to be a factor.

I hope that has been useful as a newbie's guide to NV use. This kit is very expensive, and without selling much of my kit I won’t be in a position to own an NV monocular myself. I believe I will always be a committed, traditional visual astronomer; I have a large element of masochism in me which leads me to take the harder route to achieving my observing goals, so I will always enjoy being under a dark sky and observing with just optical aids. That said, I am in the very fortunate position of being in one of the few (only?) clubs in the country with two NV owners (and a possible third around soon), so I have been able to enjoy the technology without the sizeable investment! It really is a game changer in terms of being able to observe faint objects from poor skies, if you can afford the stakes to play! The interesting point is that it also benefits from being under dark skies, just the same as regular observing, so ultimately we are still all after the same thing! Less light pollution please!

With grateful thanks to @GavStar ??

[GavStar]

Very interesting report @Stu. Like you I’ve definitely found dark adaptation and averted vision help with NV - and I’ve no idea why apart from the NV screen is not bright at all when you get the gain adjusted so I guess the rods do start getting used.

I’ve also found that after several observations of the same object over a period of time I can tease out more detail. Eg I remember the first time on the rosette with NV at Walton was a bit disappointing but now in SW London I can get some really good detail. Transparency and speed of scope key as well.

And a key point you make is that under dark skies night vision is truly wonderful. Hopefully we get lucky tomorrow evening at our Club dark sky trip...

[Davey-T]

Great stuff Stu, nice to hear what NV is capable of though not expecting to invest in it myself, you certainly managed to pack a lot in a couple of hours, I guess the GoTo helps 

Dave

[Stu]

3 hours ago, Davey-T said:

Great stuff Stu, nice to hear what NV is capable of though not expecting to invest in it myself, you certainly managed to pack a lot in a couple of hours, I guess the GoTo helps 

Dave

Thanks Dave. I've had better views with Gavin's kit and better skies, but it is nice to be driving it myself. It works well in the Mewlon which I hadn't even considered before; Gavin suggested it because he uses a C11 for galaxies.

The Goto certainly helps, I'm enjoying having the GP-DX ready to go at short notice and it makes finding targets under my skies much easier.

[RobertI]

Very interesting report Stu, hope you get to try NV with your equipment at a dark site for comparison. Based on previous NV reports (from memory at least), I thought you might see a bit more of the detail in objects with your Genesis - did the absence of detail disappoint you? Perhaps this will be improved on a dark site trip. 

[Stu]

16 minutes ago, RobertI said:

Very interesting report Stu, hope you get to try NV with your equipment at a dark site for comparison. Based on previous NV reports (from memory at least), I thought you might see a bit more of the detail in objects with your Genesis - did the absence of detail disappoint you? Perhaps this will be improved on a dark site trip. 

Thanks Robert. Straight answer is yes, it was a little disappointing vs previous experiences, but ultimately how can you call seeing the Horsehead with a 4" scope disappointing? 

I think transparency, or lack of it was the main problem. These faint objects are very susceptible to poorer transparency so I'm sure I would get better results on a different night. I will try again and report back.

[RobertI]

Thanks Stu, NV is certainly a new world, good luck. 

[Paul73]

Oh dear Stu. This is going to get expensive. The seed is sown.... you’ll have one by Christmas (possibly missing another kidney along the way, but have NV you will).

I enjoyed the read. Especially the varied targets. Is your Tak too slow for NV to really fly?

Paul

[Stu]

5 minutes ago, Paul73 said:

Oh dear Stu. This is going to get expensive. The seed is sown.... you’ll have one by Christmas (possibly missing another kidney along the way, but have NV you will).

I enjoyed the read. Especially the varied targets. Is your Tak too slow for NV to really fly?

Paul

I'm hoping I will be able to resist this one Paul. It's not just the NV monocular itself, the adaptors and filters are a fortune too!

I've not tried the Tak, for nebulae speed really makes a difference so the Genesis will be better, for global and clusters I guess the Tak would be better, but more aperture is what helps on those.

[Paul73]

29 minutes ago, Stu said:

I'm hoping I will be able to resist this one

I’m Remembering when a kind gentleman lent me his Lunt Wedge ‘to see how I got on with solar’......

I’ve still got it* and Ha gear too.....

Paul

* I did buy it from him. Rather than just refusing to give it back.

[Highburymark]

Terrific report Stu - great to have another account from a different location. Transparency is crucial - from central London it can be the difference between seeing a nebula and not. 

[David Levi]

That was a very interesting read. It's good to have a new starter's point of view.  I was surprised by how many targets weren't great.  GavStar's picture of Orion with Barnard's Loop is seared into my brain.

After reading a few NV reports I see there is mention of a 'gain' adjustment. Would adjusting this have given better views on some targets even from your light polluted site? Whatever it is the gain does for NV.

[Stu]

21 minutes ago, David Levi said:

That was a very interesting read. It's good to have a new starter's point of view.  I was surprised by how many targets weren't great.  GavStar's picture of Orion with Barnard's Loop is seared into my brain.

After reading a few NV reports I see there is mention of a 'gain' adjustment. Would adjusting this have given better views on some targets even from your light polluted site? Whatever it is the gain does for NV.

Thanks David. I think, as mentioned, alot of the success or not is down to transparency. On a more transparent night I'm sure I would have had more luck.

The gain seems to turn the brightness up, but it increases both the background and the target so I tended to keep it fairly low to middling. At higher gains there is alot more scintillating which makes the image quite artificial. Down at lower gains the view is much more natural.

[jetstream]

On 28/03/2019 at 08:04, Stu said:

some level of dark adaptation is required because looking at my phone on even on half brightness still significantly reduced the amount of detail I could see afterwards. Setting my phone to low brightness and red really helped.

Great report Stu.

Our eyes will adapt to the level of light presented to them, up to their limit in true darkness, where complete adaptation occurs, over time. So yes,exposure to brighter light than your NV screen produces will negatively affect your ability to see objects, IMHO.