24-70mm f/2.8 G Condensation Inside Front Element

This is a new one on me. I was out walking around with this lens mounted on my D810 yesterday, and it was fine for a good hour and a half or better. I did get splashed a few times(there's a bit more of a story to that), but nothing resembling full immersion or even a light rainstorm. I wasn't too worried when it happened as I did have a filter on the front and also I thought these cameras and lenses were supposed to be weatherproof at least up to the point of being safe to use in moderate rain.

 

In any case, I put it up to my eye to use it and noticed that it looked very "cloudy" through the VF. I pulled the polarizer off the front of it, and found a nasty spot of condensation just under the front element. This came up rather suddenly-I have photos taken 2-3 minutes before where I can see no signs of it.

 

Fortunately, it cleared about an hour late(I made sure to keep it dry and also tried to let it get sun on the body) but I still wanted to ask if anyone has seen anything like this.

 

At the time I took this photo, it had already shrunk some. It started out about the size of a half dollar.

 

 

 

Those lenses are water-resistant but by no means waterproof. On the rear end that is a rubber gasket, but this is a zoom and the front extend and contract. There is a pretty big gap between the front and rear barrels. For example, when the lens is extended, if water falls on the front barrel and you zoom back, that will certainly bring some water droplets inside.

Thanks Shun-that makes sense. I'm just glad it cleared!

but I still wanted to ask if anyone has seen anything like this.

Yes, several times.

Lenses cannot be made hermetic, otherwise air pressure would stop them zooming or focussing freely. So if you get humid air inside a lens it'll condense out on any cold surface it can find - usually the inside of the exposed front element.

 

You're lucky it cleared within an hour. Sometimes a mist spot will hang around in a lens for the best part of a day, or until you can artificially warm it.

However, the water is still inside the lens body. I'd rack out the zoom and pop it in a sealable sandwich box with a bunch of silica gel.

On a trip to Okinawa during a typhoon, my Leica M6 lived inside my jacket. The high humidity caused condensation on the inside surfaces of the viewfinder. The condensation quickly disappeared but caused flaring pattern of dust that stuck to the finder surfaces. At that time the camera was 20+ years old and I imagine a lot of dust accumulated over the years. A simple top plate removal and cleanup was required (simple but expensive).

Your newish lens shouldn't have much accumulated dust, but if it does, this phenomenon should be easy to see.

As Mike suggests, you should now try to dry this as thoroughly as possible. Leaving any residual moisture in the lens is just asking for fungus.

If you have no silica handy, stick the lens, extended, in an old pair of socks and stick it in a Tupperware container surrounded by dry rice. Even better. All good in the morning and the rice will be fine :-)

This 'rice as a dessicant' meme keeps doing the rounds.

Is there any evidence that it works?

 

I seem to recall that somebody tested the myth once, and found that it was no more effective than just leaving the wet object to dry naturally in open air.

 

If rice really did have some deliquescent/dessicant properties, wouldn't every opened bag of rice quickly turn into a soggy mess?

Edited October 13, 2020 by rodeo_joe|1

The effectiveness of commercial desiccants and uncooked rice in removing moisture from hearing aids - PubMed

 

Only if it absorbs enough to turn into a soggy mess.

Starting with the drop on barrel possibly going inside per Shun's post, what probably happened is that your hand on the aluminum barrel warmed the lens during the period when moisture was inside the barrel, creating the potential for a higher than ambient dewpoint inside the lens. The front element would have been closer to the outside temperature, which likely would have been lower than the dewpoint inside the lens, creating the condensation. The moisture itself is "distilled" but could combine with residue present on the glass or in the air within the lens to leave traces of the event. If using a desiccant to dry, the desiccant does need to be regenerated periodically to remain effective. They don't work forever on their own.

 

Am adding to this post to recommend that all with expensive gear living in humid climates store the gear in a room with a dehumidifier to help reduce the possibility of fungus growth in the equipment. This year has had crazy moisture in NC, seems more than normal. I just dumped my dehumidifier 4x in the last 24 hours, in mid October!.

Apparently a old, well read, paperback book if left on a hot radiator overnight is a very good extractor of XS moisture.

 

Read is so the pages arn't too tightly bound.

 

and old, so it's cotton rag paper, rather than modern 'tree' paper.

I'm a chemist and know dessicants.

 

I will snag some Dri-Rite and seal it in a bag and hopefully stick it in a dessicator for a few days to dry it out. There should also be some silica gel around here somewhere(I'm still learning the lay of the land) which of course I can bake overnight, although I'm not particularly fond of handling loose silica gel.

I've had this happen to my old 24-120 f3.5-5.6 VR years ago when I exited my air conditioned car on a hot and humid day in the Smoky mountains. It looked like I was seeing fog through the D700 viewfinder. After hiking for 20-30 minutes it cleared up. It hasn't happened since and I still live near the Smoky mountains and go out on hot and humid days for an air conditioned car.

This 'rice as a dessicant' meme keeps doing the rounds.

Is there any evidence that it works?

This just had to be tested, since the Internet 'evidence' seems equally split between supporters and nay-sayers.

 

Sooo. Two days ago I locked a beaker of water and some rice in the obligatory Tupperware container - as recommended by every wet-phone pundit on the Internet.

 

Method: 100gms of water was weighed into a 100ml beaker using digital scales with a 0.1gm precision. 100gms of rice was also weighed out using the same scales. The beaker was placed in the centre of a 15cm diameter sealable food container. The rice was loosely scattered around the beaker and the food container sealed with its close-fitting lid.

 

The container was then left for 48 hours in a room at an average temperature of 20 degrees C.

 

The free surface area of water was measured at 2,350 square millimetres (5.47cm diameter).

 

At the end of 48 hrs both the rice and water were re-weighed.

 

It was found that the beaker of water had lost 1.5gms, while the rice had gained 1.4gms.

 

Conclusions: Since the precision of the scales used was only 0.1gms, the weight difference (between water weight lost and rice weight gained) might well be accounted for by the lack of precision. So it might be said that 100%, or close to, of the evaporated water was absorbed by the rice.

 

However, the amount of water transferred is not great, being about 0.75ml per day. The same amount could easily evaporate into free air @ 20 C, and quite possibly at a greater rate.

 

Objections might be raised that 100 gms of rice isn't a large amount, but in response it has to be remembered that absorption is related to surface area. Therefore a small amount of loosely packed rice might well have a similar or greater exposed surface area than does a greater weight of tightly-packed rice.

 

Myth sustained or busted?

Well, there's a grain of truth in it (sorry!)

Rice will indeed maintain the humidity of a sealed container at a fairly stable value, but actually dry out some waterlogged object? That's still debatable.

 

The real question to ask is: Is the rice + sealed container treatment any better than simply leaving your drowned phone, or whatever in open air in the warm? Or playing a cool hair-dryer over it? Or using a sous-vide sealer or vacuum luggage bag to create lower air pressure around the object?

 

I'm pretty sure that if my phone got soaked I wouldn't mess about with bags of rice and tupperware. I'd want to extract the water by some far quicker and more reliable method. A vacuum or partial-vacuum would be my first choice.

Edited October 15, 2020 by rodeo_joe|1

How about a smaller and more realistic volume of water and some controls? You could try box + rice vs box without rice vs open air, see how much water is left in each case, then write it up for publication in a journal that accepts frivolous research in the Christmas issue. Might even have a shot at the Ig Nobel for physics.

"internet" and "evidence"??? As in "internet evidence"?

But you put evidence between quotation marks, so you know.

 

The internet is the largest and most effective way of spreading mis- and desinformation the world has ever known. By far. You will have to look no further than PNet to find 'evidence' for that. And PNet is quite well behaved in comparison to what you generally find on the internet.

Luckily, there still are some places that are a bit better than the rest, but even there you have to remain suspicious.

 

Dessicants may be used to dry equipment that is really soaked, but you will need a lot for that. Put it out to dry in the sun first.

In general, by the likes of us, they are used to reduce humidity in the air to prevent mostly the growth of molds. You do not need to absorb a lot to have an effect. Though it will be a neverending task.

Edited October 15, 2020 by q.g._de_bakker

I've had this happen to my old 24-120 f3.5-5.6 VR years ago when I exited my air conditioned car on a hot and humid day in the Smoky mountains. It looked like I was seeing fog through the D700 viewfinder. After hiking for 20-30 minutes it cleared up. It hasn't happened since and I still live near the Smoky mountains and go out on hot and humid days for an air conditioned car.

I just turn the aircon around to heat and put the lens up in front off it and 30 seconds later the lens is clear and ready. I have done that the last 20 years without noticing any damage to the lens.

rodeo_joe|1 - the statement that rice method is working may be more efficient, that your test. I am living in a rice country - I am not a farmer or expert - and there is numerous type of rice here and the there is a relative big difference how good/bad they absorb water.

Put it out to dry in the sun first

Wot, you mean wait for next summer?

 

Crazy man....:D

Wot, you mean wait for next summer?

 

Crazy man....:D

Yes. That's life. But take heart: everything is heating up nicely.

everything is heating up nicely.

Guess you must be in the Southern hemisphere...;)

 

Just had our first frost of the year last night!

 

It's that time where if you breath out just as you raise the camera to your eye, the VF has misted over...:eek:

That's why we invented houses and heaters.

That's why we invented houses and heaters.

...and i believe people make little houses with heaters to keep their camera gear comfy too....:cool:

Yes... even in warm, no, hot climates.