masmiffy 82 Posted March 24, 2011 Report Share Posted March 24, 2011 Was out last night with a mate rabbit shooting using his 17HMR Shot like a plum but such is life I guess! Noticed a couple of times the the picture thro the scope was less clear than normal due to fogging / mist on the lenses. Just wondered what do people do to try to help eliminate it? We shoot off the top of his Vitara so the gun is exposed to the elements for quite long periods. Quote Link to post
Tomm Parr 30 Posted March 24, 2011 Report Share Posted March 24, 2011 (edited) Was out last night with a mate rabbit shooting using his 17HMR Shot like a plum but such is life I guess! Noticed a couple of times the the picture thro the scope was less clear than normal due to fogging / mist on the lenses. Just wondered what do people do to try to help eliminate it? We shoot off the top of his Vitara so the gun is exposed to the elements for quite long periods. It might be the same problem that I had with fogging many years ago with an old scope. Every now and then i used to remove the scope and leave it on a shelf above the radiator for a day when the heating was on. The warm air rising from the radiator drove the moisture from the scope by evaporation and the fogging stopped. It sometimes came back every few months so it must have been a drop of rain getting into the scope somehow every now and then. That worked for me anyway, though you'd need to sight the scope again after doing this. Not sure if that is the proper way to resolve it but it worked for me, let me know... Edited March 24, 2011 by Tomm Parr Quote Link to post
matt_hooks 188 Posted March 24, 2011 Report Share Posted March 24, 2011 I had a scope which did this fairly regularly. I took the eye bell off and left it in front of the fire for an hour or so, then refitted the eye bell whilst it was still warm, that seemed to cure the problem. The issue is the air inside the scope being warmer than the outside air, and hence the lenses. The air meets the lens and cools, meaning it can't hold the water any more, and so the water condenses out onto the lense. Quote Link to post
dadioles 68 Posted March 24, 2011 Report Share Posted March 24, 2011 I had a scope which did this fairly regularly. I took the eye bell off and left it in front of the fire for an hour or so, then refitted the eye bell whilst it was still warm, that seemed to cure the problem. The issue is the air inside the scope being warmer than the outside air, and hence the lenses. The air meets the lens and cools, meaning it can't hold the water any more, and so the water condenses out onto the lense. Scopes are dry nitrogen filled when new but over time the o'rings perish a bit and moisture gets in. As matt and tom suggest, you need to let it warm up and dry out. The biggest problem I get on a cold night is my breath fogging up the scope and my glasses. Quote Link to post
masmiffy 82 Posted March 24, 2011 Author Report Share Posted March 24, 2011 I had a scope which did this fairly regularly. I took the eye bell off and left it in front of the fire for an hour or so, then refitted the eye bell whilst it was still warm, that seemed to cure the problem. The issue is the air inside the scope being warmer than the outside air, and hence the lenses. The air meets the lens and cools, meaning it can't hold the water any more, and so the water condenses out onto the lense. Scopes are dry nitrogen filled when new but over time the o'rings perish a bit and moisture gets in. As matt and tom suggest, you need to let it warm up and dry out. The biggest problem I get on a cold night is my breath fogging up the scope and my glasses. The scope is brand new and the fogging is on the external of the front lens, goes with a wipe but is bloody anoying and make it harder to see!! Quote Link to post
chimp 299 Posted March 24, 2011 Report Share Posted March 24, 2011 use the anti fog stuff you use on motorbike visors . and stop blaming fogging for your poor shooting lol Quote Link to post
masmiffy 82 Posted March 24, 2011 Author Report Share Posted March 24, 2011 use the anti fog stuff you use on motorbike visors . and stop blaming fogging for your poor shooting lol I am blond mate just hadnt thought of that one!! Cat Crap it is then!!!! Shooting wasnt that bad I guess 17 picked up and in your freezer, Pete recons we 'lost' another 6 or 7 so 24 in total for 35 rounds. Not my usual high standard I admit but wont get me in the olympics this time round eh! Quote Link to post
matt_hooks 188 Posted March 24, 2011 Report Share Posted March 24, 2011 Fogging on the outside? Sounds like a cold scope and warmer air then, strange! Once the rifle is at ambient air temp, you shouldn't have a problem with it. Quote Link to post
markha 99 Posted March 25, 2011 Report Share Posted March 25, 2011 I have had this happen before when out lamping in misty air, water dropplets built up on the lenses. RainX Quote Link to post
weejohn 3 Posted April 1, 2011 Report Share Posted April 1, 2011 The stuff you need to try is fogtech. This happened to me several times and i assume it was caused by the scope lying across my back during freezing conditions. Quote Link to post
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.