GavStar

53 minutes ago, Martin Meredith said:

Agreed, very interesting to get a feel for the experience. The mount sound adds a lot to the 'live-ness'. Given you've set the exposure to 1s, it made me wonder what the kind of non-NV based EEVA stuff I do would look like at 1s exposures for these objects. There is a qualitative difference between the kind of image produced in this way and those from an astro camera without NV -- different kind of noise for one thing, and a different nebula vs star balance, the latter much tighter in NV it seems. Please do post more of these when you can.

Thanks Martin. Please could you expand a bit more on nv having a much tighter nebula vs star balance?

On YouTube there are several videos of observing with night vision monoculars. They are fun to watch and give a “feel” of what night vision astronomy is about. However, generally I feel the videos do not show how nice the actual live views are and have a lot of scintillation in them. I have posted quite a few still phone images of the view through my night vision monoculars but have so far struggled to get my phone to produce decent videos of the live views.

However, after watching a few more night vision videos this week, I decided to have another attempt using the nightcap camera app. This app enabled me to adjust the frame rate and iso used for the video recording. By reducing the frame rate to 1 per second and reducing the iso to a relatively low 650, I’ve managed to produce some videos that, although not as good as the live views, do give a reasonable feel of the live nv experience. These were done using my 92mm refractor, 67mm eyepiece and pvs-14 nv monoculars giving around 10x magnification. The first video is a mini tour through Cygnus ie North America, gamma cygni, crescent and nebula containing the elephant’s trunk. The second is a tour through Sagittarius Witt the lagoon, Trifid, swan and eagle nebulae.

I want to stick just with my phone rather than get a specialist astro camera, but hopefully I will be able to gradually improve the results. It was a lot of fun producing these!

2 minutes ago, Deadlake said:

Is your 16" Dob going to stay on the Isle of Wight or will you bring it back to London light pollution?

Wondering if above a certain aperture with NV you need a darker site? 

It’s staying on the Isle of Wight for now. I don’t think my partner would be happy with it clogging up the boot each time we visited 🤣 My c11 is absolutely fine for when I feel like more aperture in London or darker sites in Surrey/Sussex.

14 minutes ago, Ships and Stars said:

What about NV on a larger dob? I imagine that would be mind-blowing.

I'm considering putting something from the NV world on my 20". The 500p weighs 75-85kg all in, but breaks down quickly into smaller parts and sets up in about 15 minutes if I'm really moving fast.  I don't need a ladder per se, just a step about 20-30cm high to view at zenith. I feel like I am starting to find the limits of what I can see with my 20" under dark skies, which is an awful lot, but there are also tons of very faint galaxies I'd like to see in more detail and I'd also like to see a lot more from my 20.25-35ish SQM-L home if I can't drive to my rural spots.  Gerry does have the benefit of being able to wheel his dob out under dark skies right at home, so his mirror might not need a lot of cool down if his storage area is more or less unheated, or at least considerably colder than the interior, plus he has wolves to keep him company  which is honestly rather spectacular!

Now for larger extended objects, NV on something with a shorter focal length like my 12"  (300mm/1500mm) flextube would presumably show a lot as well. Even binoculars...

I suspect in the future NV will continue to edge into the realm of mainstream astronomy, but there will always be the big reflector crowd, the direct, natural naked eye views are amazing, but the option to add NV if desired would produce a real powerhouse I'd imagine...

Interesting to think about, I wonder how the image quality of NV compares though to naked eye astronomy (i.e. looking through eyepieces)? I imagine there would be flicker and much lower resolution. I seem to recall the human eye can see about 300dpi on average, maybe a bit more.

Anyway...fun to think about

My dob is not a 20 inch but quite close and in combination with my night vision monocular I think the views are amazing with very good image quality. Not sure I’d like to go up against Gerry with his 24 inch one though 😀

I’ve just found the an interview with the founder of William Optics, William Yang, where he discusses the Pegasus Binoscope. The English translation is towards the end 

https://www.binomania.it/william_yang_intervista/
 

I note that the original 10 units (of which mine was one 😀) sold out very quickly. But he is making a new run for 2021.

Here’s some phone shots of recent visual views from my London back garden through the Binoscope (with my night vision monoculars). (Rosette, monkeyhead, California, soul and heart nebulae)  It’s a really impressive instrument. 

These are my bad boys. A 103mm William optics Binoscope. Fantastic widefield views of the skies...

2 hours ago, Stu said:

We had a first club meet up since lock down last night, and met up at the local village green. I just took my Tak and Heritage 150p and only viewed the Moon. The seeing was actually pretty good, quite surprising given the wobbliness during the day.

It was good to be able to do a meet up after such a long time. Shame I forgot that I didn’t have a diagonal attached to my AP130GTX! However luckily I had my tec turret to use instead which was quite fun to rotate around for easy magnification changes.

1 hour ago, Piero said:

My new 16" dobson cooling down 🙂

I do like a 16 inch f4 dob. Here is mine, a Skyvision t400. Any more details you can share on yours, eg mirror maker, who built yours, etc?

I’ve just done a video montage of recent phone pics I’ve taken using my ovni-m night vision monoculars and a variety of scopes including a 16 inch dob and a 40mm refractor. The images give a very good representation of the actual live visual views at the eyepiece.

I have just watched Al Nagler of Televue talking about how night vision monoculars turn an 85mm refractor into a 10-14 inch scope. And suddenly up pops a couple of images I recognise 😀. 
Link attached

Great report Max. Nice to see a night vision report given there are only a few UK astro nvers.

Currently, the skies are not that conducive to night vision with a small scope as a) night vision is more impressive on emission nebulae, and b) due to need to use long focal length eyepieces (to get brighter views), the image scale is too small for many of the objects as you stated. I think a minimum of 10 inches aperture is really needed with nv to get the best of these smaller objects.

August/September will be a great time for your nv plus 90mm refractor as Cygnus will be high in the sky and Sagittarius is also nicely visible. A few days ago I got up at 3am to catch these with my nv and 103mm Binoscope. Absolutely fantastic views even from light polluted London of the North American, pelican, gamma cygni, crescent, eagle (dark pillars of creation visible at 10x mag), and swan.

As an experienced observer, I’d be very interested in your initial thoughts regarding standard glass observing vs night vision observing? Which objects do you prefer with each one etc?

As already mentioned, I do rather like AP scopes. Here is the unboxing thread for my AP130GTX 

And here is a comparison I did between my tec140 and my AP130GTX which eventually resulted in me selling the tec as I just preferred the views the AP gives me. Also the Ap is so wonderfully compact compared to the tec140

But the AP130GTX is bested my my Tec160fl (unsurprisingly)

My little AP stowaway is pretty special too

I always enjoy observing with my AP scopes, they just put a smile on my face each time. 😀

15 minutes ago, Highburymark said:

A particularly interesting point you make Brian, and my experience also chimes with this.

@Highburymark do you mean that in single stack mode your Solarscope setup shows limited surface detail? What about proms? Are they better in single stack or double stack?

16 minutes ago, Solar B said:

I attempted a Lunt Triple stack in 08 with an LS60 and two 50s (no external 60s back then) and of course it didn't work (posted on CN at the time), as I recall an Andy Denvy did often "very" successfully image with a rare Coronado/Solarscope 100/90/90 crossover triple stack , again on CN some 10yrs ago from memory , more recently on here I tried a 60,60,40 Coronado with some more success than the Lunt , I'll try a 60mm triple as soon as conditions allow in Scotland 🌞

I think that factory matched DS scopes & filters perhaps more recently ? do tend to preform much better in DS mode than SS  meaning that they appear to be heavily set or weighted toward DS views and my recent experiences concur.

But Lunt v Solarscope 😅

Brian 

 

I did a side by side of my lunt 60mm DS vs my new Solarscope 70mm double stack (attached to a televue 76) last summer and unfortunately the views through the Solarscope setup just wasn’t as good as the lunt. The Solarscope filters went back to the Isle of Man to be adjusted but even when they came back the setup wasn’t performing as I wanted. Just goes to show how difficult it can be to get these filters performing optimally. I’m very keen to check out Mark’s Solarscope setup (which is virtually identical to mine) as I know he is extremely happy with his.

I’ve had a six month break from solar but this week had a good opportunity to use this setup again. This time I installed the telescope express adapter between the two front mounted filters. This enabled me to fine tune the setup by “clocking” the two filters. The views were even better with the surface detail and contrast noticeably enhanced in double stack mode with two external filters. I did try triple stack again by adding the internal pressure tuned etalon but although contrast was good, I thought the detail wasn’t as sharp or even across the disk and of course the views were noticeably dimmer. Going forward I’m going to stick with just the two front mounted filters and not bother with triple stacking. The views in double stack mode with Mark v binoviewers are just incredible.

I also tried just single stack with one front filter and this gave excellent fine detail on proms and still showed a good amount of surface detail, much better than the 70mm Solarscope setup in single stack mode that I had.

So @Highburymark how about a shootout between your Solarscope 70mm DS and my lunt ED 60mm front mounted double stack? 😃

Picture of the lunt setup in “clocked” mode below.

Yes great views today, one huge prom and one nice group if proms. Some well defined surface activity as well.

I tried single front stack, double front stack and triple stack (one internal, two external filters), mono and bino viewing.

Today my favourite for fantastic full surface views was double front stack with binoviewers, consistent detail across the full surface.

Just now, Stu said:

Fantastic pictures Gavin. Some of the best I’ve seen I think, great to see how you have improved your setup over time.

What is the Galaxy in the second image?

Thanks Stu, as you know it’s taken me a while to get the dob set up to how I like but I think I’m there now, it’s almost grab and go 😀.

It’s the needle galaxy, one of my favourites and spectacular through the eyepiece of my dob.

5 minutes ago, Deadlake said:

@GavStar Great pictures, taken last night? Nice you can do that when the moon is fully (~99%) out. 

No taken a few weeks ago with much less moon!

Some more phone pics with my 16 inch dob and new night vision monocular, taken recently with ovni-m (rather than my pvs-14 which I used for all the pics above). I think the ovni-m in prime mode gives sharper stars to the edge visually.

2 hours ago, Highburymark said:

Agree with all of this. Except we don’t have enough NV practitioners on SGL to justify a separate forum at the moment. Trouble is we have almost nothing in common with EEVA either. The only threads we can all contribute to are these long discussions trying to define what EEVA is. There’s no common ground - unless we use the same filters. 

 

I think some night vision discussion on sgl even with the existing few practioners on a separate nv forum would be better than the current virtual zero nv discussion that happens on the eeva forums. A separate forum might also prompt more people to consider trying nv.

29 minutes ago, vlaiv said:

For some strange reason people get defensive when talking about EEVA. In two different ways.

Some people feel like traditional observing is under attack from EEVA. I actually get this - too much in today's world is digitized and we have become heavily dependent on computers in one form or another.

I've also seen that people get defensive on the notion that night vision is EEVA. It really is - when using night vision device - you are actually looking at the screen. It is nicely attached in the place you expect eyepiece to be - but you are still looking at the screen. It has resolution - like 40 lp/mm and similar - which translates to DPI/PPI of computer screens by simply multiplying it with 25.4 (but is much higher res than regular computer screen at 96dpi).

In fact, I've written about this before in EEVA section. You could get exceptionally cheap night vision device for your telescope if you had higher density display on your mobile phone.

All you need to do is to connect everything up in this configuration:

And have some software to do the stacking / processing.

Problem is that you are going to get very low resolution device this way as most phones have displays that are at most 500-560ppi. With 40 lp/mm, night vision devices have 1000+ ppi - so double the resolution. This can be somewhat fixed with using very long focal length eyepiece like 2" 55mm plossl.

Alternative is to use some lens system that will project phone display onto focal plane of eyepiece. HD phone with 1920 x 1080 could easily have equivalent of 1000 ppi in that case as we could squeeze phone width (1080px) into 25mm field stop of 1.25" eyepiece - however such device would be at least 20cm long.

Night vision is very different to EAA in terms of practical usage. Cloudynights has recognised this and now has separate EAA and night vision sections. This change has been a positive development for both EAA and NV users.

8 hours ago, saac said:

GavStar out of interest is there any prospect of the cost of these units falling?  There was an NV unit advertised recently on Surplus Shed - not sure if was being made available outside of the USA though; the price was quite appealing though.  That said, not sure about the compatibility of it for astro use , it was part of a vehicle periscope setup. 

Jim 

Jim

Unfortunately I don’t think gen 3 night vision monoculars will drop in price anytime soon, particularly in Europe where they are materially more expensive than the USA. (Europeans cannot purchase USA tech due to ITAR regs). 

I bought my first nv monocular over 3 years ago and prices have remained high since. It’s important to note that for astronomy due to the narrow ha filters used to view nebulae, you do need to get good quality gen 3 technology. Lesser gen 1 or gen 2 (with the exception of photonis intens tubes which also cost £6k plus) just won’t give good results.

I think the best ‘cheaper’ option is to purchase secondhand. There is a Facebook group where secondhand gen 3 monoculars can be purchased legally. I recently saw a good spec gen 3 actinblack pvs-14 for sale for £3k there which would be great for astronomy.

From a personal perspective and as a visual only astronomer, night vision has transformed the hobby for me - it’s a real shame that it’s so expensive. From my London back garden I was previously restricted to lunar, planetary and open clusters observing. Now I can see hundreds of other Dsos including many nebulae and galaxies.

I don’t care whether it’s the original photons hitting my eyeball or not. The key thing for me is that it feels just like a ‘normal’ eyepiece when I’m visually observing AND that I can see so much stuff clearly. I’ve read about many starting in the hobby being disappointed with the ‘faint fuzzies’ etc and not really seeing much   compared to astro photos. Night vision is fantastic as a visual observer aid.

A few years ago there was a flurry of night vision posts on SGL but this stopped when the EEVA sections were introduced. I think many of us just didn’t think Night vision fitted into EEVA since it uses completely different techniques to EAA and feels much more like normal observing. Maybe in order to get more nv discussion, one of the 3 EEVA sections could be renamed to Night Vision Astronomy?

6 minutes ago, Moonshed said:

Okay, thanks for the link. “The night vision eyepiece” that you “class as just another eyepiece” is in reality an entire night vision system similar to that used by the military and requiring a power source and image intensifying tube, it’s a lot of gear, not just an eyepiece. This is what I was expecting and was confused by your description of it. I get it now thanks.

Is it a lot of gear? I can literally just put it into my diagonal and off I go like any other eyepiece. The actual in use experience is identical.

6 minutes ago, Moonshed said:

Curious as to what you mean by a night vision eyepiece that you class as just another eyepiece.

Here’s a link to the Televue section on night vision which I think is a good starting point for this approach

https://www.televue.com/mobile/TV5_page.asp?id=36

1 minute ago, vlaiv said:

Not in the same sense using dew shields that are electrically powered not EEVA.

You are still hit by original photons from the target - regardless of the fact that Mica crystal filter needs to be kept at certain temperature in order to operate on band.

Ah now you are changing it from use of electricity to original photons etc...