spandit Posted November 11, 2016 Report Share Posted November 11, 2016 After a lot of zeroing yesterday and today, I was finally happy with my DIY NV and thought I'd take it out tonight. Got to the permission and immediately saw several rabbits but could I hit them? No I couldn't. After wasting a full mag on a card target I realised the zero had drastically changed and I just didn't have the confidence to take a safe shot so I went home again & swapped the rifle for my Finnfire with a lamp. I've seen one bunny so far, on a ridgeline next to the road so not a safe shot. Before someone snarky tells me to get off my 'phone, I'm hiding up waiting to see if they'll come out again now I've stopped trampling through the leaves Quote Link to comment Share on other sites More sharing options...
spandit Posted November 11, 2016 Author Report Share Posted November 11, 2016 Well two came out to play but only one made it home Quote Link to comment Share on other sites More sharing options...
Hendrix's rifle Posted November 11, 2016 Report Share Posted November 11, 2016 Out of interest why did it move zero?? My diy never does that? Only time I can think is when it wasn't on properly (camera side) causing me to cant the rifle. Quote Link to comment Share on other sites More sharing options...
spandit Posted November 11, 2016 Author Report Share Posted November 11, 2016 I don't know. I'm wondering whether the camera could be more securely mounted internally. I do take it on and off but with Picatinny mounts I was hoping for decent repeatability (?) and the tests I did zeroing it before and after taking it on and off seemed to confirm that. It's a heavy unit, though, albeit on quite a heavy gun (Anschutz 525, PH mod) so I have to use sticks for support Semi auto still sounds a bit loud at night and the flash from the breech is a bit disconcerting in the dark Quote Link to comment Share on other sites More sharing options...
Dave-G Posted November 12, 2016 Report Share Posted November 12, 2016 Do you set it up in a way that requires the ocular lens to be rotated to focus the crosshair when fitting the NV to the scope? If so it's possible you are moving the POA from your daytime eye zero as you rotate the ocular lens if the thickest part of the lens is not exactly central. Try focusing the crosshair by adjusting the camera lens to the crosshair when the ocular lens is still in the same position that gives your eye a sharp crosshair. To get your head around that a bit easier, try fixing a 'T' range torch to a decent mount and see how its beam shifts when the head/lens is rotated. Quote Link to comment Share on other sites More sharing options...
Davyo Posted November 12, 2016 Report Share Posted November 12, 2016 Daves got it bang on spandit,plus you mention picatinny rail.Is it not a shove on unit?or is it a like a Rolaids type of unit?. Quote Link to comment Share on other sites More sharing options...
spandit Posted November 12, 2016 Author Report Share Posted November 12, 2016 I don't think I moved the ocular lens initially but don't fully understand what you mean Rolaids? It's a "Futon" type build - camera mounted into an old scope Quote Link to comment Share on other sites More sharing options...
Bangbangman Posted November 12, 2016 Report Share Posted November 12, 2016 I've had this problem but mine is a "slip-on" type. It has a thick rubber tube (stiff) that slides over the eyepiece of the scope. Twice now I've had inexcusable misses, rezero'd and it's been bang-on thereafter. I now check zero in the field, before hunting. I think the zero shift is because the tube can move in relation to the scope if pushed or twisted (though not easily.) Quote Link to comment Share on other sites More sharing options...
Rim Fire Posted November 12, 2016 Report Share Posted November 12, 2016 Have you got side paralax on your scope its a must wirh NV then you dont need to adjust focus ring i got side paralax on all three of my rifles Quote Link to comment Share on other sites More sharing options...
Davyo Posted November 12, 2016 Report Share Posted November 12, 2016 (edited) I don't think I moved the ocular lens initially but don't fully understand what you mean Rolaids? It's a "Futon" type build - camera mounted into an old scope No Rolaid 1st builds were simply the Cam mounted behind the ocular on a picitanny rail.I taee it you are using an EJ or an E700?.Also your scope has parallax adjust? Edited November 12, 2016 by Davyo Quote Link to comment Share on other sites More sharing options...
Davyo Posted November 12, 2016 Report Share Posted November 12, 2016 (edited) I've had this problem but mine is a "slip-on" type. It has a thick rubber tube (stiff) that slides over the eyepiece of the scope. Twice now I've had inexcusable misses, rezero'd and it's been bang-on thereafter. I now check zero in the field, before hunting. I think the zero shift is because the tube can move in relation to the scope if pushed or twisted (though not easily.) This is the fit i use but never had any issue,as Dave mentioned earlier its best to put the tube on.Then twist it to bring cross hairs in sharp focus (remember the cam is not the same focus as your eye so although your hairs are clear to the eye the cam will no focus the same).So after youve twisted it to focus,pull the tube off and then slip it on so the screen(if a one peice unit is vertical.If only a tube minus acreen the i would personaly have a mark on the tube to indicate the position ot the cam.Dave has a short video somewhere on here to demonstrate this. You should also have a spacer fuxed inside the tube that pushes up to the ocular end so every time you push the tube on the camera is the same distance away fron the ocular end every time.If you having to faff about without a spacer then you need to fix this issue 1st. Edited November 12, 2016 by Davyo Quote Link to comment Share on other sites More sharing options...
spandit Posted November 12, 2016 Author Report Share Posted November 12, 2016 Mine has the ocular lens (big one at the front) and the camera. That's it. The scope originally had parallax adjustment so I can focus at different ranges. I think I need to check the camera security (it's a board camera) in case it's shifting for some reason. Quote Link to comment Share on other sites More sharing options...
Dave-G Posted November 12, 2016 Report Share Posted November 12, 2016 (edited) I don't think I moved the ocular lens initially but don't fully understand what you mean Rolaids? It's a "Futon" type build - camera mounted into an old scope Aha - to be fair none of us would have remembered it was a futon with them being so rare - ignore my suggestion please. that build looks great BTW. I'm inclined to suspect the camera maybe shifts. On my scopeless builds just a 1/4 turn of a grub screw moves the POA quite a long way. EDIT having seen your last post. I wonder if the camera is slightly off centre with the centre of the objective lens - in which case the thickest part of the lens would move in an elliptical fashion relative to the sensor when rotated - which would have the same effect as moving the camera. I'm slightly dyslexic and can't always say what I mean lol... If you move a camera behind an aspheric lens the image will 'change position' on your monitor. That therefore also applies if the lens is moved in front the camera and is why we don't use zoom lenses for scopeless builds - because rotating a lens shifts.... Edited November 12, 2016 by Dave-G Quote Link to comment Share on other sites More sharing options...
spandit Posted November 12, 2016 Author Report Share Posted November 12, 2016 Could be moving, actually I recall I fitted another small lens to reduce the zoom. That might be an issue. I'll turn up a better mount for it to make sure it's fixed. The objective lens is so stiff to turn too. Don't know whether it's the grease or the spring that adds pressure to stop it turning. I think I'll temporarily remove the spring to see if that helps Quote Link to comment Share on other sites More sharing options...
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