lens fogging up

[Soma Jones]

Pardon me if this has been asked countless times before, but what does one do to prevent lenses from fogging up? I was out taking photos by a lake near my house at dawn and since I'd neglected to bring anything to wipe the lens with all I could do was keep moving.

[Peter Ryan]

Pardon me if this has been asked countless times before, but what does one do to prevent lenses from fogging up? I was out taking photos by a lake near my house at dawn and since I'd neglected to bring anything to wipe the lens with all I could do was keep moving.

Hi Soma and welcome to CiC.

Can you give us a bit more information?

Reading between the lines I assume you took your camera out of a warm environment to the lake and the cold atmosphere outside caused condensation on the lens. If this is the case then you need to acclimatise your camera to the new environment. I recently went up to the snow for a shoot. I had the camera in a warm car for the trip. We hired a helicopter for the final part of the trip so while waiting for the helicopter I opened the top of the camera bag a little to let the gear inside slowly acclimatise to the new surroundings outside. By the time the helicopter arrived I was ready to shoot it landing and also aerial shots of the mountains, etc.

If this is what happened you need to be very careful as condensation can also form inside the lens and cause damage to your aperture blades.

Is this what happened or some other reason the lens fogged up?

[Colin Southern]

Hi Peter,

It's normally more of a problem the other way around where a cold camera condenses the warm/moist air around it when you bring it inside from being out in the cold.

The one I have to be constantly aware of when shooting in cold environments is hot breathe too close to the camera as warm breath @ 100% humidity condenses onto the camera easily, and doesn't evaporate. Period! Perhaps this is part of Soma's issue?

Normally going from warm to cold environments actually does quite a good job of preventing fogging until the camera cools down.

[Peter Ryan]

Thanks Colin - that makes sense. I’m an accountant so science is not my strong point but I understand what you say. I have just been careful both ways – in and out (so to speak).

[Colin Southern]

Thanks Colin - that makes sense. I’m an accountant so science is not my strong point but I understand what you say. I have just been careful both ways – in and out (so to speak).

Hi Peter,

This kind a stuff was drilled into me during my aviation days - there can be a danger of warm air being trapped inside the camera/lens that subsequently has the moisture condensed out of it if the whole lot cools down too much, but as I say, it's more of an issue the other way. Personally I keep a couple of dehumidifiers running 24 x 7 in the workshop / studio to keep the relative humidity pretty low so - hopefully 0 I won't have a problem with this kinda stuff.

[David]

Hi Soma - Welcome to CiC. Apart from acclimatising the camera and lens as suggested above and/or keeping a lens wipe handy, it's difficult to think of any other method. Perhaps this is one of those lateral thinking problems that requires "out-of-the-envelop" thinking. Come on guys - get the brains in gear.

David

[Peter Ryan]

Hi Soma - Welcome to CiC. Apart from acclimatising the camera and lens as suggested above and/or keeping a lens wipe handy, it's difficult to think of any other method. Perhaps this is one of those lateral thinking problems that requires "out-of-the-envelop" thinking. Come on guys - get the brains in gear.

David

Buy an anti-fogging camera!!!

[Dave Humphries]

I was out shooting at Kew Gardens earlier in the year (cool spring day 10-15 degrees C) and while using the camera, I made sure I had planned a route that did outdoors mostly first, then a couple of the hot and humid tropical glass houses together.

Upon first entering the filter over lens front element misted (lens body and camera didn't, but they'd had my warm hands around them).

However, I didn't wipe it (it would have smeared), I just walked around choosing angles so I knew where to shoot from. About 10-15 minutes later, when the camera had acclimatised, the mist had cleared all by itself and off I went shooting.

Then I had to get from one tropical glass house to another via the cool outside, so I put the camera inside my jacket and dashed from glass house to tropical glass house in minimum time possible. That way I could continue shooting in the second tropical glass house without having a 'second misting'.

As has been said, going back to the cooler outdoors isn't a problem.
... and I had this all planned as a result of reading advice here

Cheers,

[Colin Southern]

Come on guys - get the brains in gear.

We did - and now we're waiting to hear if it worked

[Soma Jones]

Thanks everyone, I was kind of hoping there was some kind of magical professional photographer substance that I was unaware of as opposed to having to rely on common sense and physics. I was surprised that it was a problem that morning since the temperature inside my house wasn't that much different than outside. On the other hand the lake was shrouded in fog so I should have anticipated this. I'll try leaving the camera out in the garage overnight and see if that helps.

[Donald]

I'll try leaving the camera out in the garage overnight and see if that helps.

Just so long as it's locked (the garage, that is)

[Soma Jones]

It's not really that nice of camera, and we don't lock our houses up here.

[Colin Southern]

Thanks everyone, I was kind of hoping there was some kind of magical professional photographer substance that I was unaware of as opposed to having to rely on common sense and physics.

Unfortunately, even photographers are subject to the laws of physics

I was surprised that it was a problem that morning since the temperature inside my house wasn't that much different than outside.

It's not so much the temperature as it is the relative humidity. If you had fog outside then you'll have had 100% relative humidity outside, and unless you live in a greenhouse, it's very unlikely that you'll have 100% RH inside.

I'll try leaving the camera out in the garage overnight and see if that helps.

I wouldn't - if anything, I'd so the other way and perhaps leave it in the hot water cupboard overnight; the warmer you can get the camera the more it will raise the temperature of air that comes in contact with it and thus the more water vapour that that air will be able to hold, thus the lower the relative humidity and the less chance of condensation

[David]

There are anti-mist or anti-fogging coatings available for masks and lenses. See http://cgi.ebay.co.uk/McNett-Goggle-...ht_3068wt_1235

What effect such materials would have on a camera lens I don't know for sure, probably not a lot. I remember analysing a silicone anti-misting oil many, many years ago. It seemed to work fine, was inert and could be removed by typical aqueous/alcohol/detergent solutions. A possible disadvantage of a coating would be that it could trap dust particles with the possible result of lens scratching. Maybe a friendly optician would be able to advise.

Cheers

David

[Colin Southern]

I'm not sure why, but a scene from the movie Forrest Gump suddenly popped into my mind ... the one where Forrest is being chased by the bullies and Jenny calls out RUN FORREST, RUN!

[Nass]

I attach a little fan to the tripod/camera setup and point it towards the lens, one of those little £2.99 "handheld" fans. The moving air stops condensation forming.

[Ricko]

http://www.racevisors.co.uk/product/...hiftit-antifog

Just a thought, dont know what effect it might have on the lens.

[David]

Now there are some ideas appearing - I like the fan one, Nass (welcome to CiC BTW) - it could also blow off dust as well.

David

[JonathanC]

The problem is caused by the lens front element being at a temperature below the "dew point" of the air. The moisture condenses on the lens and it is often difficult to get it to go away. If you can keep the lens warm, by having it under your coat for example, the fogging will be reduced.
You can buy dewstraps for astronomy applications, but they are power hungry heaters and not very portable friendly.

[Colin Southern]

You can buy dewstraps for astronomy applications, but they are power hungry heaters and not very portable friendly.

Being a Kiwi, I was expected to come up with a down-to-earth & innovative solution for my recent startrails ... so I just duck taped a hair dryer to a light stand