OK brains out there, help me here.
I did some optical phyics in my degree, but as that's more years ago than I wish to admit, my theory is a little rusty now.
I'm trying to optimise the picture on my XVD NV, and have the common problem in that if I get the cross hair sharp, the target goes out of focus and vice versa. The compromise is well off being great. I can get around this by mounting my laser, but that's a bit of a shame. If I understood what's happening, I'd be a lot happier. In my simplistic view, I thought that the XVD should be receiving basically the image that your eye does, so should be focussed on the image intensifier. However, the mounting is up against the back of the scope, so well in front of that focal point I imagine. Is this the problem? If you were to move the NV back so the image received is where your eye would be, although not practical to mount, would it solve it?
Questions! I know these monoculars were tweaked by Soviet Bazaar to work at all, so someone knows the theory behind them. And yes, Ben's given me some great tips on setting it up
Spanner Woman
You wouldn't be using a 4-16x56 SWAT would you?... I struggled with that very problem with one for a long time before Ben suggested the Bushnell Banner 4-12x40 I use now.
As to the physics I think that IR is focused at a slightly different place to visible light and maybe this means some scopes work well at IR (by chance) and others it works against - a search on cameras and IR reveals similar sorts of discussions.
Beth
(not much help really)
Simmons Whitetail Expedition 4-12x42Originally Posted by beth
Tried with my son's rifle and scope, was unusable.
Hmm, didn't think about the wavelength issue! Yes, the optics would be different. Duh.
Genius loci
On mine I:
1 - Set PA on scope to that of target
2 - twist front focus on XVD til the crosshairs are pin sharp (conveniently this just means "all the way in" on mine)
3 - twist rear focus til the full sight picture is clear.
Once set I can leave the rear focus alone when taken off the gun, and just adjust the front to scan the fields - once a target is located I just have to screw it all the way in again, refit to the adapter and ready the shot
Hmm, will try that when its dark.
Goes against Ben's teaching.... But I'll try it!
Spanner Woman
If you fancy meeting somewhere dark you can have a play with the Banner - it really does work very well. The downsides of it are light gathering is a bit poor and the ret is standard 30/30.
B.
Very temping, this however, is how I end up buying things!
Using Ben's XVD was my last mistake....
And damn you all for showing me those high power laser IR illuminators.
Spanner Woman
Chuckle! Whatever. Offers there.
B.
Southern Hunter Champion.
OOeerr - indecent proposals on the BBS
Indeed. Sarah asked about this too, meeting Beth at night.OOeerr - indecent proposals on the BBS
Amazed she let me out last night. Got it set up OK, and shot a couple, it was way too still though. They could hear me coming.
Spanner Woman
OOeerr - indecent proposals on the BBS
I just knew it would be you
B.
Spanner Woman
Errrr wierd thats Lewis using Sarah's account and conjuring a most odd image in my head!Indeed. Sarah asked about this too, meeting Beth at night.
Amazed she let me out last night. Got it set up OK, and shot a couple, it was way too still though. They could hear me coming.
Talking of the rabbits hearing you I keep having trouble with my boots sqeaking. One of these days I'll end up spraying them with oil just so as the rabbits dont hear me creaping up. Just before our hols we couldn't get within 50yards it was so still and the moon was out. Going to try some early mornings without the NV just to see how we get on - probably be even harder but we'll see.
Beth
Southern Hunter Champion.
I would hate to disappointI just knew it would be you
B.
Captain Mainwaring
OK brains out there, help me here.
I did some optical phyics in my degree, but as that's more years ago than I wish to admit, my theory is a little rusty now.
I'm trying to optimise the picture on my XVD NV, and have the common problem in that if I get the cross hair sharp, the target goes out of focus and vice versa. The compromise is well off being great. I can get around this by mounting my laser, but that's a bit of a shame. If I understood what's happening, I'd be a lot happier. In my simplistic view, I thought that the XVD should be receiving basically the image that your eye does, so should be focussed on the image intensifier. However, the mounting is up against the back of the scope, so well in front of that focal point I imagine. Is this the problem? If you were to move the NV back so the image received is where your eye would be, although not practical to mount, would it solve it?
Questions! I know these monoculars were tweaked by Soviet Bazaar to work at all, so someone knows the theory behind them. And yes, Ben's given me some great tips on setting it up
On mine I:
1 - Set PA on scope to that of target
2 - twist front focus on XVD til the crosshairs are pin sharp (conveniently this just means "all the way in" on mine)
3 - twist rear focus til the full sight picture is clear.
Once set I can leave the rear focus alone when taken off the gun, and just adjust the front to scan the fields - once a target is located I just have to screw it all the way in again, refit to the adapter and ready the shot
You fella's......
Try this (!)
[i] At night, monocular in hand and off the rifle......
Using the dioptre adjuster on the monocular, turn on the NV and the onboard illuminator. Looking at the ground 15ft away, focus the adjuster so the tube image you see is sharp. Few tubes (and certainly no Gen I's) are faultless, so you'll see small black inclusions on the tube. This is what you focus on. If you are the only person that'll ever use the NV. then you might put some (insulating/PVC) tape on the adjuster to stop it rotating (again.)
The tube is then focussed for YOUR eye.
Turn off both NV and illuminator.
[ii] Before mounting the monocular, wind out the front element of the monocular. This will ensure you'll leave enough space between the lens and the ocular of your scope.
Mount the monocular.
Preferably with your rifle on a bipod or some other rest, try to arrange a situation where your main illuminator (Laser/LED/lamp with IR filter) can be seen if the NV is switched on.
Switch on the NV and the illuminator. De-focus your scope, and turn the magnification down as low as it will go. [You're looking for a blurred image really.]
Now ..... Rotate the lens barrel at the front of the NV, until your crosshairs appear sharp. The image won't be a crystal clear as the daylight image will be, but you're recognise focussed from unfocussed.
When that is done, you'll be in a position where your NV is focussed to your eye, and the NV unit is corrected to the crosshairs.
All that is left to do, is correct the (day)scope parallax to the crosshairs, which you all normally manage without any help.
[iii] Select a 'target' say 30 yards away, and parallax your image using the correction facility on your (day)scope. Sidewheels are a better tool for this, as you don't have to reach all the way forward as with an AO correction system.
UNLESS you've done something drastically wrong.... Your target should be in focus, as should your crosshairs, and the image on the tube should be as focussed as your eyes will allow.
Simple, innit.
SWAT's are really good for this system BUT quite long. We are working on a specific scope for the 'add-on' systems, but this is some months away. Anyone using a fixed mag Falcon x10 "Tactical" is going to be using one of the best we've seen for this application, but only provides a fixed mag image. Which to be honest, is what the three 'erberts I shoot with always use.
Unlike myself.
'Cos I like high mag shooting.
...
To be good, one must do good.
Almost got there, and Beth, was me posting using Sarah's account, we're having to share a PC
I suspect that as my Whitetail doesn't focus at short distances, (i.e. 15 metres and below), and I know from talking to others that with NV you need to parallax shorter, this may be where the problem lies.
I got it set up pretty well last night, just know it could be better.
Anyone re parallaxed one of these scopes? Would help with them close targets at HFT too... (That's MY excuse for missing them).
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