TNVC Night Vision for visual astronomy

[stewe]

Hi

The opportunity of using a night vision (NV) device (image intensifier) for visual hobby astronomy has been around for a little while, but I have seldom read meaningful discussions about it so far. Unfortunately, I have never had the opportunity to try it, either. Does anyone here have any first hand experience?

In case someone reading this has not yet heard about it, here is a link to TeleVue's info page about the topic:
http://www.televue.com/engine/TV3b_page.asp?id=36
They say the technology (of certain NV models) fits their "do no harm to the image" product philosophy, which seems to be reassuring to me that using an NV device on an eyepiece is not heresy.

What I am wondering about is: if someone is using a scope in the, say, 6"-8" range, and gets serious aperture fever, then can NV be an effective cure instead of investing in serious artillery (Big Dob) and subdue to all of its shortcomings? I guess the 4k USD investment for an NV device would be similar to (or less than) an investment into a 18"-20" Dob. I am also wondering about how the image in a 8"-10" scope with NV compares to the image in a huge Dob?

I hope there will be interest in a discussion.

[sdbodin]

I have seen people before think that NV cures all, stack a bunch of NVs to a 60mm drug store scope and you by miracle of science have a Palomar on the back porch. But, light doesn't work that way. It is photons flux that determines what you see in an image, small scope gather fewer photons and amplifying that is almost meaningless. Bigger is better or the pros would give up on 10 meter monsters and buy Tak 106s instead.

Four K bucks would buy a really nice OSC camera that would provide color images in near real time to a small flat screen or laptop. That's what I do when guests are over to see the stars. They look thru the Bigdog eyepiece and see the faint fuzzy thing and then see a better view on the screen from the 80 riding on top with my Asi1600MC attached shooting 1 min exposures.

So, rather than a mono image from NV tech, I would go with the astrophotography tech.

Just thoughts,
Steve

[stewe]

Thanks for your answer. In my opinion, astrophotography and visual astronomy are two very different kinds of experience, though. One cannot be a substitute for the other. AP, as photography in more general terms, is kind of an art, the process of creating the image gives most of the experience. Looking at great photos is fun, but it is not the same as looking at the object through an eyepiece, even if it is fainter, at least it is not for me. Likewise, looking at stunning nightscape time-lapse videos is fun, but it is not the same as lying under a truly dark sky and getting lost in the view, even if you don't see that much faint detail with the naked eye. If these were the same experiences, I would not have a scope and would not go out at night, but I would be looking at professional astrophotos on the internet instead. Likewise, looking at 1-minute unprocessed single exposures on a screen by the telescope for a "better view" of a faint object as you suggested is not an alternative of looking into an eyepiece.

My understanding is that looking through an eyepiece combined with a night vision device is not the same as looking at a screen, since one is effectively not looking at a screen. Also, in my original question, I was not considering putting a white phosphor NV device on a 60mm drug store scope, but rather on a 6" refractor or an SCT. I am wondering how a C9.25+TNVC would visually compare to the views provided by a huge (say, 16-18") Dob.

It would be great if anyone in this forum had a first-hand experience with that kind of a setup, could share it with us.

[pakarinen]

You might want to check over on cloudynights.com on that one. There's a whole subforum devoted to electronically assisted astronomy.

[Voyageur]

When one looks through an NV device, one is looking at a screen, a phosphor screen not unlike an old style TV. Light energy from the photons coming from the object is converted to electrons. The electrons are amplified by a multiplier. They exit the multiplier and hit the phosphor screen, which then emits photons. That's what the viewer sees.

People seem to be divided on the nature of the viewing experience with an NV device vs a camera-to-computer setup. Some suggest that since they are looking through an eyepiece, the experience is more immersive, and they feel like they are looking at the actual object more than with a camera to computer (or other display, e.g. phone) But the NV image is no more or less "real" than the one on the computer. In neither case are the actual photons from the object striking the viewer's retina. It seems to some that the NV setup provides more of the impression of seeing something in real time than looking at an image on an external display does.

And that seems to be a personal choice. You would need to look through an NV device to decide if you find it to be a more immersive or genuine experience. The flickering of the image as seen in YouTube videos seems bothersome to me, and in my thinking, it would detract from one's ability to discern detail in objects. I have no doubt that I would appreciate and enjoy a look though one of these devices, but for now it isn't something I really want for myself. However, I can certainly understand the enthusiasm, especially for those in light-polluted areas. Ultimately, I am all in favor of any equipment that truly enhances someone's enjoyment of the hobby.

[Lady Fraktor]

NV devices amplify ALL incoming light so if in a light polluted area it will amplify that as well.
You will need filters of different wavelengths to help cut down some of this extra lighting (usually red for street lighting)
NV can get very expensive, very fast.
A good basic system can easily start at $3000USD, a decent advanced system will be $5000+ and that is just the system with no required spacers/ filters etc.
I tried the PVS-7 style (BV) at a star party and the cost for the enhancement received was not worth the money.
Between the BV style and Monocular the Monocular has more clarity.
EAA is a much simpler and less costly solution.