How to stop/prevent Lens Fog?

[AzzA]

Hi all, just came back from a month long trip to China, Hong Kong, and Japan. Took so many photos that i'll be posting up eventually, but thats a whole other story.

I was wondering hoe many other people have had problems with their camera lens fogging up?

I tryed a search on this topic, because i think i rememebr someone mentioning it a while ago, but i couldnt seem to find any other threads.

Lens fog had never happened to me until i was in China. The MASSIVE humidity and temperature changes between indoors and out seemed to cause my lens to fog up (i think?).
Is there a way to avoid this? Any tips on preventing it from happening? Or quick ways to get rid of it after its happened?
It was quite frustrating at times, as it seemed to happen when i was in a really interesting area, and prevented me from taking photos from time to time.

It might be a dumb question, but i thought i'd just ask anyway.

cheers

[arthurking83]

I've never had this happen to me(lens fogging) but I have had the viewfinder fogging up!
(maybe the lens did fog up, but I didn't notice it because I couldn't see thru the finder?? )

Of course it begs the question, was that misting up 'inside' the lens or on the front or rear element?

If it was only the front/rear element that's a simple matter of cleaning with a micro fibre cloth.

If it's fogging up 'inside' the lens body,.... well .. you wait!

ps. I was once told by a service tech(of a camera sales company, not Nikon or Canon tech) and they specialize in rentals etc... to clean an obviously grubby lens.. breath on it with a HUH! and wipe with a micro fiber cloth! .. easy done.. and he gave me a small micro fiber cloth too!

But he said never rub/clean a dirty lens with a cloth if it has smeary type stains(like from child with chocolate covered fingers, or glucose lolly lip marks.. etc) without any moisture of any type. He just said moisture, not mentioning any particular lens cleaning solutions or anything like that.. just moisture.

[Ronbo]

I have had this a number of times...usually the opposite way....going from a cold outside to a warm inside.

The key is to acclimate the camera...meaning you should have it in a bag of some sort and give it time to allow the lens/camera to warm or cool down to whatever ambient temperature you're in. the key is to be patient, because it can take a little while to acclimate so plan ahead.

[I @ M]

Its not a dumb question at all , had the similar thing happen in Bali in January. I think what you are seeing is a combination of things Azza, if you are taking the camera from a bag and then taking the lens cap off you get a sudden change in temperature for sure. Where I think the fogging occurs is
#1 in or on the view finder
#2 the front or rear elements of the lens
#3 and this is the one I reckon that I experienced the most , BETWEEN the front lens element and any filter you have on at the time UV etc.

As noted by AK and Ronbo, patience and planning are the key in tropical conditions and after our January trip there appear to be no permanent issues with any lens we took over.

[ricktas]

Get some of those absorbent GEL packs (that sometimes come with new purchases). Those little ones that say 'do not eat' and put them in the bag with your camera gear, especially if you are going to places where humidity is an issue.

Replace them regularly.

A bit of fogging on the outside of the lens elements are easily cleaned as stated above, BUT, fogging inside the lens is BAD, and that is where those gel packs come to the rescue. Moisture inside a lens can lead to mould (another thing that likes the same warm moist environment).

http://www.jceh.co.uk/0953-6833/16/jceh_16_46_028.html

[ving]

astronomers use a dew zapped to stop dew forming on eyepieces, etc... that would work

[arthurking83]

......Those little ones that say 'do not eat' and put them in the bag with your camera gear, especially if you are going to places where humidity is an issue.

.....

Damn! I ate all mine!

I always thought they were a little dry!