Sony 24-70 f2.8 GM fogged inside

[peterbkk]

This evening I went for a walk. Singapore: inside aircon 24 degrees 50% humidity; outside 31 degrees 95% humidity. So, when you take a lens outside it sometimes fogs until it reaches ambient temperature. The fogging is always on the front glass (or UV filter). Sometimes a gentle wipe with a clean lens cloth speeds up the clearing process - it also cleans the front glass quite well.

 

But, today was unusual, the fogging was not on the front glass, not on the rear glass, not on the sensor: the fogging was on an internal glass element somewhere inside the lens barrel. I could see it clearly by looking through the lens. It was quite a small element somewhere about a 1/3 into the lens from the rear.

 

What's also strange is that it did not fog straight away. The camera had been out of my camera bag for at least 15 minutes and I had taken about 20 images - crystal clear, with no fogging. Then, suddenly, the EVF looked misty and, after investigating, I saw the fogging inside the lens.

 

After another 15 minutes the fogging had cleared.

 

I am not familiar with Sony lenses nor zoom lenses. Are they not sealed? Is this internal fogging usual? Should I be taking it back to the store? It is brand new.

 

 

Regards

Peter

http://www.peterwalker.com

[reyh66]

Changing from cold to warm will cause the fogging.. They will clear, mine happens between the filter and the front element

[Golem]

Zoom lenses can act similar to a bicycle tire pump.

 

So don't zoom, or zoom extra slowly, so as not to

pump outside air into the lens during extreme high

humidity. Most lenses are NOT sealed, apparently

including your zoom. 

  

A humid air mass supports many impurities. A tiny

bit of that is left behind when an internal fog clears

by itself. You obviously can't clean off internal fog.

This effect is cumulative. Repeated tiny deposits

can add up, such that you'll have a hazed surface

somewhere inside the lens :-(

[Mr_A7s]

Not on my GM, but on my Canon 2470 II in my last trip in Hong Kong. Took an early walk outside the city and humidity was high. Fog gone not too long after.

[fractal]

To avoid fogging going from cold to warm quickly, use a hairdryer to warm up the lens a bit before heading out.