Image intensifier eyepieces

Hey everyone,
Has anyone here ever got or used one of these image intensifier eyepieces, such as the Collins I3 or some equivalent, I've read the reviews and the good and bad, you read all the US reviews and was wondering had someone here had used one

What do they exactly do Dave, improve contrast ? I have never heard of them myself and would be interested to know

Keith..

Hi Keith,
Apparently on the right objects the I3 can multiply your aperture by about 2.5 times according to the manufacturers, you can find reports of people easily and fully resolving m13 and other globulars with 4 inch aperture scopes and so on, they use photo multiplier vacuum tubes.
they have their drawbacks though, extreme cost for one thing and you can forget about dark adaption, their effectiveness on some faint extended objects is hit and miss.
I got a cheapo night vision monocular from lidl a few years back and am going try it out on my next outing on the the 20 inch, but I'm wondering how good a proper system would really be....
I was wondering is their any local experience with an I3 or something similar....

Dave,
I would be very interested in trying one but alas never seen any.
Have you considered making your own?
www.imageintensifier.org.uk
and results discussed here
www.thornett.net/Rosliston_Archive_2009-...age_intensifier.html

Hi Michael,
I had a good long look at making my own over the weekend, same site you found, its trivial enough technically and would cost about 100 euros to do, I tried my lidl intensifier (not attached to anything) on the clear sky here tonight and noted a few things,

its great for getting those faint stars, excellent limiting magnitude, well beyond what you'd see without it
but ...
narrow field of view, a loss if you're used the wide fov's
sky glow is amplified, swamps out faint nebula, you need a dark sky...
will deffo wipe out your dark adaption.

so, I've made up a rig where I can put this thing on the eye end of a 31mm nagler, I'm hoping its wide fov will help give a decent overall fov. I'm also going to dismantle the intensifier and see if I can run the intensifier tube attached directly to the scope, running in prime focus mode instead of eyepiece projection mode,

One problem I see with the ex military tube is that they're wider then a 2" focuser, so for my newt where the focus point is inside the focuser, you'd need to be able to put the tube in the focuser barrel, and since its wider, you wont be able to. I'd have to make up a second focuser on the scope or raise the primary mirror and risk loosing aperture....
It would take a little experimenting to get right....