jan van daalen
Well-known member
Thank you Lee for defending the honour of my more private parts........
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Victory SF: Condensation on ocular lens (1 Viewer)
- Thread starter J899
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Thank you Lee for defending the honour of my more private parts........
So then you are attributing the superior fogging resistance of the ELSV to the Swarotop hydrophobic lens coating factory applied on the ELSV's? So then your actual field experience supports the theory that a Lotutec type coating as used by Zeiss does aid in the prevention of fogging. I have used these anti-fogging lens coatings on my scuba mask while diving also and they are quite effective. We also commonly spit in our mask before diving to prevent fogging. Sounds weird but there is something in saliva that stops condensation from forming on the inside of a diving mask. I believe you are correct in believing that these anti-fog lens coatings could damage the factory coatings on the binoculars. So the theory of a poorly applied Lotutec coating by Zeiss could very well affect the fog resistance of the lens.
I agree about the defects being put right under warranty but I think these threads are an excellent source of information about various problems with the Zeiss SF. These threads get a LOT of reads so they are interesting and valuable to a lot of forum members. Your input is very valuable as a Zeiss SF owner and I appreciate that but I feel the thread still has some interesting points to discover. For example, new information has come in that shows these coatings do aid in fog resistance. Too me that is VERY interesting and I will definitely make a note of that for my next binocular purchase.
jan van daalen
Well-known member
This morning I woke up from a dream that Dennis surfaced out of my more private part with a typewriter in his hands and a 8x32 round his neck, while writing a letter to Swaro CS complaining that the hydrofobic protection coating of Swaro did not give any protection to ........ and than I woke up screaming.
Can anyone explain what happened?
Lee, where were you when I needed you?
Jan
kestrel1
Well-known member
Based on my field experience, my assumption is that combination of hydrophobic coating with such high lens diameter and properly designed eyecups increase "vaporisation" of condensed water microdrops.
ELSV has fair big surface of eyepiece lens, and probably eyecups enable air circulation. Regarding Lotutec coating, I do not have my Zeiss this winter, so I will try it next time. To be honest, it is annoying, if binocular fogs up in best moment in winter.
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perterra
Well-known member
I think it's called channeling.
Doesn't any hydrophobic coating, by definition, repel water?
It wasn't a dream Jan, he does that all the time.
Me? I was making a cup of tea, it seemed like the most constructive thing to do.
Lee
perterra
Well-known member
To a degree, when conditions are right it will fail to do the job. My eye glasses were coated, yet they fogged over.
The fogging part is a red herring, not knowing the conditions it happened in means it happened, nothing else. Spend a while on the gulf coast in the summer, everything will be fogged.
It's just something else for denco to go on and on and on about. If it were a swaro, you would hear crickets chirping before you heard a peep from denco.
Yes, that is the idea.
But I think the concept of 'repelling water' is slightly misleading. Raindrops will still land on the lens.
LotoTec and AFAIK all the others create a situation where the base of the droplet that is touching the glass is too small in surface area to support the weight of the drop so that the drop runs off.
In my extensive experience of standing for hours in the rain in the Western Isles of Scotland with both my spectacles and binoculars equipped with LotuTec I can say that this system works well for medium and large rain drops. With these size of drops their weight is such that with the small area of base that LotuTec promotes the drops run off due to gravity. If the drops are smaller than medium then they don't tend to run off, but a vigorous shake will get rid of most of them.
Fogging produces a thin film of fine droplets which can be so tiny that they don't have enough weight to run off or be shaken off. I find that fogging doesn't happen very often, probably because we don't go out in cold enough temperatures. But it has happened in Novembers and has been caused by me pushing the bins too close to my face or lowering the bins to look with my naked eyes and accidentally breathing on an eyepiece. In these circumstances I wouldn't say the coating helps much, although to be sure the coating does make wiping and drying with a microfibre cloth easier and more effective than having no coating.
Fine mist-like rain acts more or less like fogging. It can cover the lenses but won't run off due to the small droplet size.
My wife has the same experience with her Leicas and I have the same experience with the Swaro EL SVs that I have been testing. They all work well with drops of water above a certain size.
I think these coatings are a great help and wouldn't go back to being without them.
Lee
HighNorth
Well-known member
I think Zeiss should outfit their binoculars with force fields to prevent that from happening!
HN
Hydrophobic means "Water Hating". When a dog or animal contracts the Rabies they become hydrophobic. They can't stand even the sight of water. That is how these lens coating like Lotutec work. They repel the water and cause the water molecules to bunch up into larger groups so the water runs immediately off your binocular objective instead of just sitting there disturbing your view. In some cases like when condensation tries to form they will stop it before it has a chance to settle on your binoculars objective by repelling the microscopic condensate drops which if enough of them accumulate will form a visible drop. Kind of like a magnet repelling fine metallic particles. If you don't believe it take a non-Lotutec coated binocular and a Lotutec coated binocular(A Swarovski with Swarotop could substitute for this sample) and put them side by side. It is preferable if you put them in the refrigerator for awhile to get them cool(Be careful with the Zeiss SF we don't want them to rust). Now breath on each ocular simultaneously by putting them side by side and see which one fogs up first and most importantly which one clears up first. You will see every time the Lotutec coated lens will take longer to fog up and will clear up faster than the non-Lotutec coated lens. Try it!
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Life`s too short. Pity this thread is`nt.
You could be right about this Dennis but you make my point for me: LotuTec coated lenses do fog.
BTW the most recent example of fogging eyepieces occured during my testing of the Conquest and Terra 8x32s and the CL 8x30s. I was holding a binocular in each hand and holding them together, one on top of the other in front of my face, so I could switch quickly from one to the other. Several times I fogged one of the eyepieces of the lower pair of bins with the breath from my nose while I was looking through the upper pair.
Lee
Let's try again.
Any hydrophobic coating is, by definition, non-wettable.
This is irrespective of whether the surface to which it is applied "fogs" or not. The substrate is, and remains, not wet.
On a clean substrate, droplets of water spread into a film, which is the definition of "wet" I believe.
Any hydrophobic coating is, by definition, non-wettable.
This is irrespective of whether the surface to which it is applied "fogs" or not. The substrate is, and remains, not wet.
On a clean substrate, droplets of water spread into a film, which is the definition of "wet" I believe.
