Night vision compared to dark adapted naked eye

[danieldan256]

Hello,
I am an amateur astronomer who is considering a night vision device to use for astronomical observation. I would like anyone's opinion regarding the performance of a generation 1 NVD compared to a fully dark adapted human eye. I will not be using an infrared illuminator. If anyone has had any experience using a NVD for astronomy I would appreciate any suggestions. Thank you,
-Daniel Champion

 

[ewick]

Re: Night vision compared to dark adapted naked ey

danieldan256,

Welcome to the board. You're in the right place for honest feedback. There's plenty to be learned around here.

So, onto your question. There is no comparison between a night vision device and dark-adapted vision. Even with a Gen I device, the least impressive, you'll see a great deal more than with dark-adapted eyes.

But as far as astronomical use is concerned, I'm not really sure. Gen I devices are GRAINY. And there's enough grain to ruin any detail you would be looking for. Plus, you won't be able to get much magnification, so you'll be left staring at a bunch of pinholes. As a beginner, unless you already have a telescope, I would suggest spending the money on an entry level telescope or some good binoculars. I think you'd be more satisfied.

Hope this helps. If you give a little more detail about how you plan on using the NVGs, we might be able to give some better advice. Good luck.

 

[danieldan256]

Re: Night vision compared to dark adapted naked ey

Thanks for the reply,
I allready own a telescope that I plan on using with the NVD. I would mount the NVD after the eyepiece (perhaps removing the lens on the NVD)and project a focused image on the photocathode of the NVD.

 

[ewick]

Re: Night vision compared to dark adapted naked ey

I've not looked at this stuff for a while, but depending on your telescope and the model of the NVD you're looking at, you may be able to find a T-adapter that will allow you to mount the NVD directly to the telescope.

The only problem I can think of is overloading your NVD. This stuff is designed to operate in low light, and if you sweep across a bright enough object, there may be enough light to damage the photocathode. I'm not sure about this, and someone here may be able to give a more definitive answer, but it's something to consider.

 

[augon]

Re: Night vision compared to dark adapted naked ey

I've used a Gen II+, one power, on a telescope afocally behind an eyepiece, and have not been impressed. The stars stand out brighter but nebulosity is not better than with the naked eye through the eyepiece. Graininess and resolution are a problem with my unit, so Gen I will be worse. I would not recommend using a Gen I at all. My Gen II+ is all but worthless for telescope use, and I would guess that a Gen III would not be much better than that.

Having said all that, there is an eyepiece specifically made for astronomy that employs a Gen III unit and is claimed to be good. Big $$$. I have not looked through it. The company is in Denver. You might take a look at their website: http://www.ceoptics.com/astroindex.html

For visual observing of the sky, my Gen II+ 1x NVD is absolutely fabulous. The one power eyepiece gives the same image size as just my eyes, so you sort of end up with one bionic eye and one normal. I am able to see stars at least 3 magnitudes fainter with the unit. It does not help nebulosity very much. The stars are spectacular. You will see more meteors - even those not visible to the naked eye. I see meteor counts at least 3 times greater than what is normally reported. NVD's are sensitive to the near infrared, so the meteors will be more visible even without the light gain. You'll see many more satellites too. A good NVD opens up a whole new world of visual astronomy. Wildlife observation is great too. Everyone who has ever looked through mine is blown away. Needless to say, you will lose night vision in the eye using the device. Don't point at bright objects like Venus, Jupiter or moon.

IMHO, don't waste your money on any Gen I unit, nor on any brand using tubes made by other than Litton, ITT, or Phillips. The optics on the front end are important too. Some of the cheaper units have lenses that are like looking through a clear marble - small central part OK but all else smeary looking! You need fast lenses f1.2 or better. That's one of the reasons why good NVD's are expensive. Forget the cheapies. Save your bucks and buy the good ones - Gen II (American rating of units - not foreign) or better.

Hope this helps.

 

[manyclouds]

Re: Night vision compared to dark adapted naked ey

Unless you have other uses for night vision devices,what you want for astronomy is a ccd camera www.sbig.com/ www.starlight-xpress.co.uk/ www.newastro.com/newastro/default.asp. Google image intensifier or ccd and you'll discover a whole new world for your telescope. These ccd's are gen 4/5, you have to prove your a citizen and promise not to sell it to ANYONE overseas.

 

[manyclouds]

Re: Night vision compared to dark adapted naked ey

BTW what kinda telescope you got ? Me a 12.5 Dob f 5.6 . My friend a 12" schmidt cass and a TV 101 (really cool thing a H alpha filter for it saw the venus transit in technicolor !!! )

 

[manyclouds]

Re: Night vision compared to dark adapted naked ey

http://www.pacificsites.com/~brooke/ACCD.shtml#NVD