Lens annoyances--fogging and defogging

[VanessaN]

Hello,

This weekend I had another reoccurance of a really annoying phenomenon that I was wondering if there was any quick fix to. It's about the third time or so this happened, but it really shouldn't have this time.

The first two times had obvious reasons as to why it happened. Both were Tamron lenses, and the first time I had gone from a chilly Niagara Falls temperature to a humid butterfly house. The camera which had been next to my chest under my jacket, and the lens fogged, and was pretty much useless. The lenses in my bag were fine, and so I had to use those instead, but at first I thought the first lens had been damaged as it took nearly to the next day to defog.

The second time it happened it was not winter, and another butterfly house, so the temperature change was not drastic....this time it was only a couple hours or two.

This weekend it was my Canon 28-135IS lens, probably the best lens I have right now, and it was really important that it worked. I was outside the entire time, at a race track for the Smarty retirement party. I was "out back" with an owner photographing her horse, outside the stables, and also in the barn, but the barn is an open barn,with plenty of breeze and open areas. Then we went to the track to watch horses work, and this is where it fogged up instantly. The day was not overtly hot at that point (10am), slightly muggy due to oncoming aftereffects of Charley that evening, and it had been around my neck for at least twenty minutes (and as I said, outside). So it was all cloudy on the *inside* of the lens (like the last two times also). It looked like a frosted area covering most of the lens, with a slight round clear area in the middle, but otherwise everything through the viewfinder was dim due to the haze. It was not the outside of the lens, nor the rear of the lens where it connects to the camera--I wiped all of these and the viewfinder itself.

It took 6-7 hours for the frosted area to melt, so to speak, too late for the Smarty party. I had to leave the rear cap off and the front cap off the lens in my backpack. I was forced to use my 100-400 Tamron to take pictures of Smarty who was 5-10 feet away from me in the winner's circle, and the 28-135 would have been more than adequate. Never mind that the Canon is a better lens as well. I could really have used the IS.

In any event, when I specifically have to go somewhere to shoot things, and it's summer (and not even a greenhouse for heaven's sake), it's really irritating to have a lens out of action. Totally ruins my whole day.

Is there anything quick to defog a lens? Any special tricks? Dump it in something cold? (like that's convenient) It's really annoying, especially when it's during moderate temperatures without drastic weather changes!

Thanks,
Vanessa

[opus]

The kind of fogging that you describe sounds weird, but I suppose within the realm of temperature changes. I've never had a lens fog unless I went into an obvious humidity/temperature change. And I've never had the inside fog up. I always thought that the sealed air pocket prevented it. Maybe your lens is damaged and no longer sealed? That might explain why even a bit of humidity caught inside the lens would cause fog against the outside, and why it would take so long to defog. I'd get your lens checked out.

Otherwise, I was just at a conference this past week where several very successful photographers spoke. They mentioned fogging briefly, and they said a good trick to defog quickly is a hairdryer. I wonder if you could carry around a battery operated blow dryer?

[Michael Fanelli]

Hello,

This weekend I had another reoccurance of a really annoying phenomenon that I was wondering if there was any quick fix to. It's about the third time or so this happened, but it really shouldn't have this time.

The first two times had obvious reasons as to why it happened. Both were Tamron lenses, and the first time I had gone from a chilly Niagara Falls temperature to a humid butterfly house. The camera which had been next to my chest under my jacket, and the lens fogged, and was pretty much useless. The lenses in my bag were fine, and so I had to use those instead, but at first I thought the first lens had been damaged as it took nearly to the next day to defog.

The second time it happened it was not winter, and another butterfly house, so the temperature change was not drastic....this time it was only a couple hours or two.

This weekend it was my Canon 28-135IS lens, probably the best lens I have right now, and it was really important that it worked. I was outside the entire time, at a race track for the Smarty retirement party. I was "out back" with an owner photographing her horse, outside the stables, and also in the barn, but the barn is an open barn,with plenty of breeze and open areas. Then we went to the track to watch horses work, and this is where it fogged up instantly. The day was not overtly hot at that point (10am), slightly muggy due to oncoming aftereffects of Charley that evening, and it had been around my neck for at least twenty minutes (and as I said, outside). So it was all cloudy on the *inside* of the lens (like the last two times also). It looked like a frosted area covering most of the lens, with a slight round clear area in the middle, but otherwise everything through the viewfinder was dim due to the haze. It was not the outside of the lens, nor the rear of the lens where it connects to the camera--I wiped all of these and the viewfinder itself.

It took 6-7 hours for the frosted area to melt, so to speak, too late for the Smarty party. I had to leave the rear cap off and the front cap off the lens in my backpack. I was forced to use my 100-400 Tamron to take pictures of Smarty who was 5-10 feet away from me in the winner's circle, and the 28-135 would have been more than adequate. Never mind that the Canon is a better lens as well. I could really have used the IS.

In any event, when I specifically have to go somewhere to shoot things, and it's summer (and not even a greenhouse for heaven's sake), it's really irritating to have a lens out of action. Totally ruins my whole day.

Is there anything quick to defog a lens? Any special tricks? Dump it in something cold? (like that's convenient) It's really annoying, especially when it's during moderate temperatures without drastic weather changes!

Thanks,
Vanessa

Unfortunately, this is normal behavior. When I was in Colorado, I arranged with the Butterfy Pavillion to keep my lenses in the humid butterfly exhibit overnight. Most of the time, that worked.

Condensation will occur whenever your glass is at or below the dew point. Cold glass takes a long time to warm up. If it is a humid environment, the already condensed water can't evaporate off. My eyeglasses do this all the time. I have tried every trick and gadget over the last 30 years to no avail. You can't beat basic physics!

[p220sigmans]

Unfortunately, like Michael said, it is a fact of life. I live in FL and down here we always have high humidity. When I travel around the state on business, I am frequently up to photograph sunrises. The problem is that I like my hotel room very cool at night. Since, unless it is winter in North FL, the outside temperature in the morning is usually in the high 60's low 70's with high humidity. Obviously coming out of a very cool (usually low 60's) room into the humidity spells fog on the lens. Since I don't want to leave my equipment in my vehicle, I started putting my camera backpack in the closet of the hotel room on the highest shelf (heat rises) with the door closed. I wrap the backpack in an extra blanket or towels if no blankets are available. After I am dressed and ready to walk out the door, I grab the bag. This has seemed to help prevent the fogging in all for the highest humidity days.

I realize this won't exactly help in your situation as you aren't coming from a hotel room at the time, but there may be a a time you could use this tip.

Good luck
Terry

[tab]

I would have the Canon lens checked out by Canon. Lenses will fog under circumstances that already been listed but they shouldn't fog on the inside nor should it take hours to defog. You obviously have moisture inside your lens otherwise that wouldn't happen. When a lens fogs on the outside it's because the lens is cooler than the ambient temperature. If there is moisture in the air it will condense when it hits the cooler glass of the lens. The air inside the lens should be about the same temperature as the glass and should warm up a little faster than the glass but not enough to cause instant fogging unless the outside air is freely displacing the air inside your lens. I live down south so I have alot of experience with lenses fogging when I take them out of an air conditioned car or house into the hot humid outdoors. But when I have had them fog it was always on the outside glass and only lasted until the temperature gradient decreased. I would keep the rear cap on though.

[Clemmie]

The fog around the outside, leaving the center clear - coupled with the extreme persistency of the fogging - indicates to me the possibility of the lubricant seals being breached.

Have these lenses EVER been left in a hot car? Or laying out in the sun for several hours? Extreme overheating can cause it.

May be time for shop care.

[another view]

Something doesn't sound right here, I'd get the lens checked out too. If you use equipment in very humid conditions (or you're caught in a downpour, etc), take the gear home when you're done with it and let it dry out thoroughly before putting it back in the bag. I take both caps off of lenses, take all the stuff out of the camera bag, open up the tripod and anything else I can do to make sure everything's completely dry before it gets loaded in the bag again.

I've had lenses fog but only a few times. It's either been outside late at night when everything starts getting a layer of dew (can't do anything about this one) or because I didn't let a cold lens warm up enough before using it (like outside in the winter, then brought inside). Shouldn't happen that easily - as in the case of the Canon lens.

[VanessaN]

Thanks for everyone's help so far. Yes, I know the *outer* side of the lens will fog when going from cold to hot or humid or vice-versa, and this part is correctable with wiping until the camera adjusts, but it's the inner side of the glass that has been the problem.......and the thing is, is that I was totally not expecting it to happen on Saturday, since I got to the track at 7am, took some pictures (before security told me not to) of early am horses in training, as well as some front shots of the track entrance.

It was not cold, not hot, since I had been up that morning (had spent 2 hours on a PA bus from Philly, and 8 hours before that on a Greyhound bus from NY. And before that it was in my apartment, which has no airconditioning at all.

So after 7am I put the camera back in the bag where it sat around (outside the track) doing nothing until 9:40am, when I went back with the owner to the stables. I took a whole roll of her horse with the Canon lens without incident, outside the barn, then led her horse back in the barn and stood there for a while, then went outside and up a flight of stairs to the track. If it wasn't around my neck it was in my bag, and the bag itself had been in external and/or non-drastic elements for at least 3 hours.

The bag has not been subject to any downpours lately. And, the lens was fine with the first roll I shot. There was no discernable temperature change from climbing one flight of stairs to the track. It was breezier up there.

So, there's probably some damage, huh? (sigh) And I should send it directly to Canon? How much does this usually cost, anyway? Someone mentioned a breach--is this only caused by very hot temperatures? I have never left it outside for several hours in direct sun nor in a hot car (don't have a car, actually). I have been out for hours at a time, but it is usually in my bag, or, around my neck for extended periods if I go to the zoo (but then I am usually using my 100-400 Phoneix almost exclusively)

Thanks,
Vanessa