Compass reverse polarity – don’t keep your compass near your camera

I’ve always taken stories of compass reverse polarity with a degree of scepticism as I’ve never personally noticed any problems. But, in preparing for this year’s Challenge, I was  thinking of keeping my compass in a hip belt pocket along with my camera so I decided to see what effect it had. My expectation was that any effect would be so small as to be irrelevant.  I was astonished – there is a major magnetic effect (about 50 degrees)as you can see in the pictures below. How long it would take to reverse the polarity, I don’t know but for sure it is a possibility.

Compass 1

Compass with camera












I also tried other devices – a SPOT tracker which had no effect whatsoever and an iphone, which had a very minor effect. Probably too small to reverse polarity but I wouldn’t risk it. So – be careful and don’t keep your compass in the same pocket as your camera.

3 thoughts on “Compass reverse polarity – don’t keep your compass near your camera

  • May 5, 2015 at 11:00 am

    Wow. Thanks for sharing the info Ian.

  • May 5, 2015 at 1:45 pm

    It happened to me in the Picos about three years ago. In my case I had my compass in a pouch on the rucksack shoulder strap – well away from cameras and the like, but unfortunately right next to the magnetic clip on my new Osprey hydration thingy.

    Navigation became a right mucking fuddle until I figured out why the sun had moved!

  • May 6, 2015 at 8:20 pm

    Great info Ian – I was always aware of it but never seen it demonstrated so starkly. Last weekend on Culardoch I made sure to stow my compass in the same pocket as my wind gauge, but not mobile phone. Anything with a ‘large’ battery in it will have a magnetic effect.


Leave a Reply

Your email address will not be published. Required fields are marked *