Zero Change when using Night Vision

Kran

So i was just zeroing my air rifle with my Night Vision add on attached to my scope. I zeroed it with NV on and just for the sake of it I checked zero with it off. There was around an inch of a difference between the two. When the NV is on I have it zeroed dead center and when off its shooting an inch high. How is this possible? My add on is simply a camera looking down the scope, shouldnt it be the same zero? the only thing I have to adjust when fitting the camera is the eyepiece ring to help focus the crosshairs for the camera. You can never get it just right so its a balance between clear pic and clear cross hairs, I go for slightly out of focus cross hairs and sharper picture.

Cass

On the mobile so I'll keep this short and sweet.

I imagine it parallax. Improper focus of thee camera, which is different to blurred image, which causes the cross hair to "move" with your eye and hence the shift in poi.

reniwren

Seeing your previous posts, you have a spring air rifle, adding the night vision effects the way the gun will recoil throwing off the zero

Kran

reniwren wrote: »

Seeing your previous posts, you have a spring air rifle, adding the night vision effects the way the gun will recoil throwing off the zero

No it’s not throwing the zero off, it is just an inch lower with the NV on. It holds its zero steady. I zeroed it with the NV attached and fired 30 shots and it’s bang on. Take the NV off and fire again and the POI has changed by an inch but still it’s holding consistently. I can’t understand it.

reniwren

With your spring rifle consistancy is the name of the game, adding something that effects the mass of the rifle will effect the way it recoils throwing off your shot, removing remove the night vision and it will return to normal. Only thing you can do about it is zero it each time you add/remove the unit or invest in a night vision/daytime scope, not ideal but unfortunately it happens

Kran

reniwren wrote: »

With your spring rifle consistancy is the name of the game, adding something that effects the mass of the rifle will effect the way it recoils throwing off your shot, removing remove the night vision and it will return to normal. Only thing you can do about it is zero it each time you add/remove the unit or invest in a night vision/daytime scope, not ideal but unfortunately it happens

That actually makes perfect sense, the weight of the NV unit would obviously remain constant so the POI change would be consistant too, which it is. I’ve never had a problem with it on my 22 or 223. Re zeroing it each time is no problem, I was just worried I’d a bigger problem on my hands. Thanks for the input.