All fogged up

RIFLES

When I travel to my stalking grounds in a warm car my scope’s lenses fog up in the cold weather. What, if anything, can I do to stop this?

It can indeed be a real pain when you get to your shooting grounds after a long drive and then, when you remove the rifle from its case, the scope’s lenses fog over with condensation in the colder air.

If it is just the external surfaces that are fogging or showing signs of condensation, it is not too bad — it is when the internal of the scope fogs that you have a bigger problem on your hands. This means that the scope’s seals have failed and the inert gas used to purge the scope to keep it dry has escaped. This will require repair by the manufacturer.

However, it is more likely that the rifle is warm from the car and it is simply the change in temperature causing the problem. To prevent this, keep the rifle in the case but put it in the coldest part of the car — for example, the boot — and then when you arrive at the shoot bring it out and unzip it and let it acclimatise a while to the new temperature. Also open the scope’s flip-up covers if it has them.

It is best to wait until the condensation does not form any more, as you know what will happen — a deer will walk out and you won’t be able to see it, and it is dangerous too. I also always have a small scope cloth in a pouch that attaches to the sling so I can keep the scope clear if necessary as I stalk. BP

Let your kit acclimatise when you arrive, and open the scope’s flip-up covers if it has them