First light - night vision from central London

[Highburymark]

I recently took delivery of a PVS-14 night vision monocular with a Photonis 4G intensifier tube, and I've finally had the opportunity to try out the new gear with my Equinox 80ED (F6.25) and Takahashi FC-100 (F7.4) - although these are only first impressions - based on two short sessions.

Eyepieces used were TeleVue Plossl 55mm and Panoptic 27mm, and Baader Aspheric 36mm. Filters: Baader Ha 7nm and 685nm IR-Pass.

Location - central London. Without actually taking the telescopes to Piccadilly Circus, it's difficult to imagine a more challenging site for observing dsos in the UK. Just to add to the fun, the school at the end of the garden has four spotlights on all night, and the Moon was prominent throughout.

Hovering around Cygnus with the 80ED, 55mm EP and Ha filter, the distinctive shape of the North America Nebula popped out at just 9x. Clearer and more prominent than I've seen before at dark sites. The Pelican was less impressive, and the Veil only faintly apparent with averted vision. However the Gamma Cygni Nebula stood out beautifully - and I spent the rest of the session gawping at it, absorbing the fact that NV technology could show such detail through a 3" telescope in London.

Then tonight, I moved to the 4" Tak/36mm and 27mm EPs, with 685nm filter, and swept along the Milky Way from Cygnus to Cassiopeia. Wonderful to see so many stars against a dark background from the city. By turning down the 'gain', it's easy to achieve views that are indistinguishable from normal glass. Stars are tight - though I did notice some astigmatism at the edge with the 36mm Baader Asph eyepiece. The two TeleVue EPs appeared better corrected for faster focal ratios at which NV excels. Caroline's Rose, double cluster - both very nice. M39 too. Then a memorable view of M31. The core was brighter than I've seen even at darker sites, and there was a little more structure to the rest of the galaxy too, though interestingly I couldn't see either of the companion galaxies. Finally, just saw M81/82 as tiny wisps in the lower level urban fug.

So much more to look forward to, but at this early stage, the monocular has outperformed my expectations for urban stargazing. Can't wait for M42 and maybe a few globulars with the 27mm Panoptic. And a few trips outside the metropolis....

[alanjgreen]

Nice one Mark. Good that you are up and running...

Try to keep the f speed up as high as you can to get maximum bang for your buck. Which probably means using the 55mm plossl as much as possible.

Have you got a goto mount?

Buy a copy of the Bracken Astrophotography Atlas for £20 off Amazon then you are set...

https://www.amazon.co.uk/Astrophotography-Sky-Atlas-Charles-Bracken/dp/1517687802/ref=sr_1_1?ie=UTF8&qid=1542578936&sr=8-1&keywords=the+astrophotography+sky+atlas

Alan

[Highburymark]

2 minutes ago, alanjgreen said:

Nice one Mark. Good that you are up and running...

Try to keep the f speed up as high as you can to get maximum bang for your buck. Which probably means using the 55mm plossl as much as possible.

Have you got a goto mount?

Buy a copy of the Bracken Astrophotography Atlas for £20 off Amazon then you are set...

Alan

Thanks Alan - just using manual alt-az at moment but will get an AZGti at some stage.

[GavStar]

I’m very pleased the NV is doing well for you Mark. It adds another dimension to the hobby particularly for those of us who normally observe from heavily light polluted sites. It sounds like your garden is even worse than mine ? But getting the moon out of the way will make a big difference for you on nebulae. I also find nebulae are so much better when they are high in the sky (obvious really but the difference is much greater than I expected)

When I began to use NV I knew getting a fast f ratio was important but I didn’t realise just how IMPORTANT! 

I’d suggest getting the adapters so that you can use the monoculars at 1x mode with your 2 inch 7nm Ha at f1.4 (I think that’s the speed of the pvs-14). This will get 4x the amount of light in compared to using your f6 refractor and a 55mm plossl. I think it would be a great way for you to assess how much difference a super fast setup would make in your garden. I didn’t use 1x with an Ha filter until about six months after I got my NV monoculars and that was a mistake imo.

For example, I was scanning the Milky Way with my 1x setup and blobs of nebulae just kept appearing - I had to refer to the bracken book (definitely worth getting ?) to check out what I was observing. The tadpole nebula (IC 410) was one that stuck out. But all of the heart and soul, California, rosette were really bright and clear.

I also managed to get a distinctive view (without averted vision) of the full loop of Barnard’s Loop and the Angelfish nebula.

As you know, I’ve now got my ‘specialist’ NV scope, the Tak Epsilon 130d working well with the 55mm plossl. It took me a while to get the spacing adapter sorted - I discovered by trial and error that 2 inch eyepieces work fine with the Epsilon focuser which I wasn’t expecting. This gives a focal ratio of f1.6 so very nearly the same as the monoculars on their own and about as fast as you can go for visual use. And 4x the light of my ‘normal’ refractor setups. 

With a 55mm plossl the magnification is only 8x and the fov is around 5 degrees but it gives awesome views of the North America and California nebulae from London - real detail in the views and bright!

I also used the Epsilon at the weekend on Orion. The rosette was lovely - showing good detail of the various wisps of nebula and I could also see the dark running man bit in the rosette. I’ve never got near that view before in London. The flame nebula was clear with the dark lanes running through it very obvious. However at the low magnification of 8x the horsehead was small and so although I could see it, it wasn’t easy to make out the snout - but I did get there in the end.

A bit more of a ramble than I meant to do. ? 

The sky background always comes out grey rather than black in my phone photos from my back garden in London (dark sites are so much better for phonetography) but here are a couple of examples to give an indication of what the Epsilon can show from London LP with night vision.

 

[Stu]

1 hour ago, GavStar said:

The sky background always comes out grey rather than black in my phone photos from my back garden in London (dark sites are so much better for phonetography) but here are a couple of examples to give an indication of what the Epsilon can show from London LP with night vision.

I had a quick tweak with these two in Snapseed, which is an app I've just discovered for Android. The results with just a small amount of effort were very good, so at Gavin's suggestion I'll just post a little description of the process here.

After opening the image, I selected Tools, then went into Curves.

In here, you can see the graph showing the content by level, and by tapping the 45 degree line you can add control points which can then be dragged up or down to change the intensity of the graph at that point. By a process of trial and error I found that pulling the lowest levels down and leaving the areas of content unchanged the image improves considerably.

This is all trivially basic stuff to an imager, but having this functionality on a phone is very handy. Screenshots attached, then the results.

[Highburymark]

Excellent advice - thanks all.

[GavStar]

2 hours ago, Stu said:

I had a quick tweak with these two in Snapseed, which is an app I've just discovered for Android. The results with just a small amount of effort were very good, so at Gavin's suggestion I'll just post a little description of the process here.

After opening the image, I selected Tools, then went into Curves.

In here, you can see the graph showing the content by level, and by tapping the 45 degree line you can add control points which can then be dragged up or down to change the intensity of the graph at that point. By a process of trial and error I found that pulling the lowest levels down and leaving the areas of content unchanged the image improves considerably.

This is all trivially basic stuff to an imager, but having this functionality on a phone is very handy. Screenshots attached, then the results.

 

 

Many thanks for posting Stu, particularly helpful screen prints. I was finding it difficult to remove the grey sky background without affecting the nebulae - this method works a treat! ?

[PeterW]

Worse light pollution that me?? Unfortunately probably possible in central London... if you can read your charts without a torch then I feel your pain;-)

Great to hear your new toy is delivering the views! 

PEter

[Eastman]

On ‎18‎/‎11‎/‎2018 at 22:53, Highburymark said:

I recently took delivery of a PVS-14 night vision monocular with a Photonis 4G intensifier tube

Great stuff, nice report. I getting more and more interested into NV.

But how do you attach the PVS-14 onto the eyepiece, do need adapters or special eyepieces?

[alanjgreen]

8 minutes ago, Eastman said:

Great stuff, nice report. I getting more and more interested into NV.

But how do you attach the PVS-14 onto the eyepiece, do need adapters or special eyepieces?

The simplest option is to import the TNVC/Televue adapter from USA (if you use TeleVue eyepieces).

Alan

[PeterW]

Simples.

Peter