night vision and light polution

[apaulo]

i was out last night with my gear at a local dark site. a passer by with his dogs stopped and chatted. he had a night vision viewer with him that he asked me to look through. wowwww what a bit of kit. i always knew about them but never looked through 1. it raised an immediate question within me. if they can turn dark into light why not a reverse item for the sky. maybe in my ignorance they do exist and ive never seen or heard of 1. we seem to get offered bits of glass that work with 1 thing and not another and seemingly quite useless. does anyone know of anything affordable that does work to make milky skies dark.

[GavStar]

53 minutes ago, apaulo said:

i was out last night with my gear at a local dark site. a passer by with his dogs stopped and chatted. he had a night vision viewer with him that he asked me to look through. wowwww what a bit of kit. i always knew about them but never looked through 1. it raised an immediate question within me. if they can turn dark into light why not a reverse item for the sky. maybe in my ignorance they do exist and ive never seen or heard of 1. we seem to get offered bits of glass that work with 1 thing and not another and seemingly quite useless. does anyone know of anything affordable that does work to make milky skies dark.

With night vision astronomy we use strong filters to remove the “milky ness”. Eg for viewing stars and galaxies in my London back garden I use a Baader 685 filter which filters out the visible wavebands just leaving the infrared which can  be seen by the night vision device. Works very well and with the manual gain adjustment you can get really quite black skies but retain lots of stars.

It’s expensive though unfortunately.

Here’s a thread I posted recently about how light pollution does affect night vision astronomy. For the observing discussed in this post I was using a narrowband ha filter to observe the emission nebulae. Some light pollution does sneak in hence the more milky views but night vision still allows you to see stuff you would have no chance otherwise.

 

Edited November 10, 2021 by GavStar

[RT65CB-SWL]

21 minutes ago, GavStar said:

With night vision astronomy we use strong filters to remove the “milky ness”. Eg for viewing stars and galaxies in my London back garden I use a Baader 685 filter which filters out the visible wavebands just leaving the infrared which can  be seen by the night vision device. Works very well and with the manual gain adjustment you can get really quite black skies but retain lots of stars.

It’s expensive though unfortunately.

Forgive my ignorance @GavStar, are you saying the Baader 685 filter can be used for visual as imaging?

[GavStar]

1 minute ago, Philip R said:

Forgive my ignorance @GavStar, are you saying the Baader 685 filter can be used for visual as imaging?

Only when attached to a night vision device. 

[RT65CB-SWL]

1 minute ago, GavStar said:

Only when attached to a night vision device. 

OK! Thank you for clarifying. 

[johninderby]

There is a cheap alternative to the Baader filter if you want to try an IR pass filter.

https://www.amazon.co.uk/Svbony-Astrophotography-Telescope-Photographing-Planetary/dp/B08P453951?th=1

[apaulo]

will this ir  filter  work for general observing. i have realised very quickly that bigger prices very often dont mean bigger improvements in astro gear in general. thanks for the advice and input.

[apaulo]

im sorry guys i forgot to state at the start, that i meant usage in observing, i dont do any serious astro photography.

[GavStar]

16 minutes ago, apaulo said:

will this ir  filter  work for general observing. i have realised very quickly that bigger prices very often dont mean bigger improvements in astro gear in general. thanks for the advice and input.

I use my night vision monoculars primarily for live visual observing, not imaging. However I do like taking quick phone shots of the views as a record of my observing sessions.

With respect to the ir filter this should be used in conjunction with a night vision device for live observing. 

Edited November 10, 2021 by GavStar

[apaulo]

thanks gav for clearing the ir filter up for me. so am i right in thinking that theres no filter  for observing that will  blacken the sky.

[GavStar]

14 minutes ago, apaulo said:

thanks gav for clearing the ir filter up for me. so am i right in thinking that theres no filter  for observing that will  blacken the sky.

Maybe I’m not answering your query, but For standard visual observing, depending on the object to be observed, there are various filters that can help to some extent like uhc, oiii (for emission nebulae) and Baader moon and sky glow (for planets). But these filters have nowhere near the impact that the night vision device plus appropriate filter has for light polluted skies. In this case bigger prices really do have a massive positive impact on what you can observe live.

Edited November 10, 2021 by GavStar