Using low magnifications for cruising the night skies

[GavStar]

My first experience of stargazing was with a pair of canon image stabilising binoculars. I have to say, I was pretty underwhelmed - as a novice the views didn’t draw me in, there didn’t seem to be much to see apart from dots of stars. 

It was only when I got a 6 inch SCT a few months later and saw the cloud bands and moons of Jupiter did I get hooked. With the benefit of hindsight, I think the extreme light pollution of my back garden (being in SW London) was a key culprit of my dissatisfaction with the binoculars.

So the canons were put in a cupboard and only came out for sports events, ship spotting and the odd look at wildlife. I never thought I would use low mag views on the night sky again.

Last year I purchased my night vision monoculars and I also purchased a 3x afocal lens for it (as per the photo below). 

I’ve tried the 3x lens a couple of times in the past 10 months or so but there is some material vignetting due to the need to use a filter over the inside lens of the monocular. So I have generally used small fracs such as a 60mm to get widefield 6 degree fov views of large emission nebulae and star fields.

Indeed I rarely used the monoculars at 1x until May this year when I had a lovely session on the Isle of Wight scanning the Milky Way and getting views like this

Since then, I’ve gradually done more and more 1x scanning of the night sky using my night vision monoculars. However, the significant light pollution of my London back garden has meant that I generally only use 1x at dark sites. 1x with LP just doesn’t really provide enough for me - I found that I need to use a scope to get the magnification up to see the detail I wanted.

My very positive experiences with the night vision approach made me want to try to optimise my system and get even better views. Night vision was very nice in London but my fantastic views at dark sites spoilt me a bit.

So I’ve now purchased a Gen 3 night vision monocular that provides nearly double the night vision luminance gain. I’ve also just received a Chroma 5nm Ha filter to hopefully bring out the contrast on emission nebulae even more.

Last night the skies were clear in London and I got to test the new kit out properly.

It was immediately apparent that the chroma 5nm provided a big jump in contrast compared to the 6nm. The North American and gamma Cygni nebulae really popped out. I was effectively getting dark sky views but in  my LP back garden. 

But I then felt that I wanted a bit more magnification to get some more detailed views. I dusted off the 3x lens and gave this a try again. Yes there was the vignetting but oh my, the views were great.

The visible fov was about 10 degrees due to the edge vignetting (compared to 40 degrees at 1x). I was amazed at how much difference the jump from 1x to 3x. Suddenly I was able to see dark lanes running through the nebula that contains the elephant’s trunk. The North American nebula showed beautiful detail with the wall section standing out, the pelican very clear and Sharpless 119 standing out as a obvious streak. 

Gamma Cygni showed nebula fluffyness all around and above it and the North America.

Moving down the Milky Way, the Pac-Man showed off his open mouth. The heart was completely visible with the various sections complete and the wide fov showed the heart and soul very comfortably. Then across and down to the California nebula where the two edges were noticeably distinct from the rest of the nebulosity.

I ended the session switching out the Ha filter for a 685 long pass to look at star clusters and galaxies. M31 was awesome at 3x with m110 also clearly visible (a new experience for me in London). M45 is great with normal glass but was also a treat with nightvision. And roaming up and down the Milky Way showed thousands of stars all across the fov with various open clusters standing out.

My previous night vision setup enabled me to see things I hadn’t seen before. This new setup with the Gen 3 monocular and 5nm Ha filter gives me detail from my LP back garden as well. I seem to be getting Isle of Wight type views!!

And the other great thing about the low mag viewing is that it only takes me a few seconds to put filters and lens on and I’m ready. Just perfect for a quick 10 minute session before bed. ?

 

[Highburymark]

Nice report Gavin - glad to see the Harder tube is delivering results - where did you get the 3x lens from out of interest? I'm rather excited as I'm ordering a PVS-14 with 4G tube tonight. Should have it next week - though thanks to your report i won't expect too much from 1x views in central London

[GavStar]

7 minutes ago, Highburymark said:

Nice report Gavin - glad to see the Harder tube is delivering results - where did you get the 3x lens from out of interest? I'm rather excited as I'm ordering a PVS-14 with 4G tube tonight. Should have it next week - though thanks to your report i won't expect too much from 1x views in central London

Very exciting Mark! ? I look forward to hearing about it. Are you going for 4g rather than echo+? Have you got the tnvc televue adapter coming as well?

I got the 3x lens from actinblack. You do need to get some adapters from rafcamera to be able to install the necessary filters inside it. Happy to give more details if you wish?

I think you will still enjoy the 1x views particularly of star fields with the 685 filter.

[Stu]

Lovely stuff Gavin. Yet another dimension to NV, and yes the ability to have a quick session which is genuinely rewarding is great. Glad the Harder tube is proving to be a good improvement over the 4G. Look forward to having a go!

[Paul67]

I darn't look at how much this gear cost's, pretty amazing though.

[Highburymark]

1 hour ago, GavStar said:

Very exciting Mark! ? I look forward to hearing about it. Are you going for 4g rather than echo+? Have you got the tnvc televue adapter coming as well?

Thanks Gavin - In the end I've gone for a 4G intens as it wasn't a big jump pricewise from the Echo+ tubes, and the ebi, FOM and gain were quite a bit better. I have found a stockist that offers reasonably competitive deals - will report back on this next week. Tnvc adapter also on its way - along with 55mm and 32mm plossls - and I'm tempted by the 18.2mm Delite IF it can deliver bright enough views of globulars and galaxies. Lots to ponder - very grateful for everything I've absorbed from you