www.nightvisionforumuk.com

Hello all!

First, let me introduce myself. My name’s Tom and I live in Manchester. I have no particular ‘use’ for night vision, but I’m a technology geek and my girlfriend’s just bought me my first NVD for my birthday as I’ve always been intrigued with the idea.

If you don’t mind, I’d like to jump straight in with a question. It’s a very newbie-ish question I’m afraid, but I did *try* and find something using the search function first!

I have a Bushnell Night Watch 2x24 (waterproof/fog-proof version), and noticed a degree of ‘fuzz’ in the image. In pitch black darkness the image looks much the same as the screen you get on an old TV set with no signal - that constantly moving mass of black and white dots. This is much less apparent when there’s enough ambient light to get a decent picture, but it is still there to a degree.

I know that I only have a low-end Gen. 1 device and should have realistic expectations, but I did want to check with you guys to see whether you thought that sounded normal for a device of this quality. As this is my first NVD I have no frame of reference, and would hate to have got a defective one and just not realised since it does still work up to a point.

Many thanks in advance for your help, and it’s a pleasure to meet you all.

Tom

Hello To and welcome to our little forum. Hope you enjoy reading up on nv.

Does the in-built infra-red illuminator make any difference to the picture at all, and if so, does it make more difference at close range? It's just that all nv can benefit form extra illumination, with GEN1 stuff being the most needy.

George

I'll try again, George beat me to it whilst I was on the phone:)
Hello.
As a Gen1 mono it will only have light amplification in the region of 1000, in a dark room with no ambient light 1000 x nothing, equals nothing.
As George says you should be able to see something if the onboard IR is turned on but this will still be limited.
It is very easy with Gen 1 gear to get the setting up wrong, if the IR is working look down at the floor and adjust the eyepiece until you can see little black specks on the rear of the tube, turn it off and fit lens cap if you have one, it will take a few minutes for the mono to turn off fully so be careful.
Then either tape the eyepiece in place as it is now focused to your eye, or mark it somehow for future reference, or wrap a laggy band around it to lessen the chance of it moving by accident.
You should now only have to use the objective lens focus to get a crisp image but you'll not do that unless you have sufficient infrared kicking about.
Larger amounts of additional infrared can be Gen 1's best friend, it can also be it's worst enemy, over exposure can burn out the tube, so again be careful.

Hi Folks,

Thanks for your replies. I think I may have given you the wrong impression with what’s wrong. I don’t mean that it’s not magnifying enough light, I mean that when there is *no* light (e.g. when I cover the objective lens) I still get relatively bright speckling dotting about. When there is light to amplify the speckling is still there but is much less noticeable.... As far as I can tell with no comparison, the image quality it produces is about as you would expect, but getting illuminated dots when there is no light for it to amplify makes me wonder if there might be a fault that may affect the tube’s performance or longevity. Does that make sense?

I was meaning to ask about tube life at some point as well actually. I’m shying away from lights as far as possible, but don’t know how sensitive the tube is to damage. When I turn on the IR when indoors the display gets extremely bright... Is that worth avoiding doing that as far as possible? And do I need to make sure when I’m outdoors with it that there’s no risk of car headlights appearing over the horizon?

Sorry for more newbie-ness!

Tom

That's sounds pretty much as I would expect, Tom.

Don't be too scared of car headlights, as it's prolonged exposure that's going to cause the damage. Just pull the unit away when you hit bright lights.

Main points are not to use in daylight or artificial light with no cap on. Don't use the illuminator indoors, or, where stuff in close proximity can cause the ir to reflect back. If the illuminator is focusable, try to vary it so that it isn't concentrated on one area of the picture all of the time.

George

Hi George,

Cheers for that. As for not using the IR indoors, so far I have done (including turning the IR on when pointing against a wall a couple of times, I'm afraid) for about 30s to a minute. Will that have been enough to cook the tube?

Tom

The speckles your on about is 'noise' loose little electrons buzzing around in the tube and thats normal and nothing to worry about