• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

NL Pure condensation on eye pieces (1 Viewer)

I took delivery of a pair of NL pure 10x42 last weekend. I am thrilled with them in every way bar one concern.

I have noticed that they are particularly prone to condensation forming on the eyepieces. This is external and starts forming after about 45 seconds of continuous viewing. I can see it disappearing as soon as I take the bins from my eyes and it goes after about 10 seconds. The left eye piece seems more prone than the right, it happens every time when viewing from inside my house and looking outside. It happens only sometimes outside, but more regularly when its cooler. My wife tried the bins inside and it happened to her also.
I can't remember this happening at all with the pair of 8.5 x 42 SV's I had for the past 6 years and it does not happen with an old pair of Zeiss I have. I tried every eye relief adjustment on the NL's and it makes little difference. The bins are stable at room temperature when I use them inside. I have also even checked the removable eyepieces with a spare set of SV and there seems to be little difference in size/shape or eye relief. The SV eyepieces don't fit the NL so I can't test in situ.

Swarovski say that as it's not internal then the bins are not at fault.

I was wondering if anyone else has had a similar experience or if there are any solutions I am missing. It seems very odd given I have not noticed before with other bins. I am loathed to keep the bins if this is a feature that I would have to live with. Any ideas welcome. Many thanks
 
How odd. This sometimes happens, as with you, looking from within the house and usually if I'm warm and it's a cool morning but once wiped no further issues. What a shame.
 
I’ve had no such issue with my 8x42 NL while birding in warm, cool and cold weather, including precipitation. But I use binoculars while wearing eyeglasses.
 
This is normal for any binocular if you don't wear eyeglass. It depends on the temperature of your binocular. If the binocular is cold (approx less than 10 degrees C) the moisture from your eye will condensate on the eyepiece. On cold mornings I alway warm my binocular on my chest to reduce the effect. Having your eyecups set shorter than normal will improve ventilation between your eye and the eyepiece.
The NL may be more prone due to having less eye relief (only 1 mm less than EL8.5 according to some) and a large occular.
 
Your binocular is cold or significantly colder than the ambient temperature. Or there is significant humidity developing between your eye and the eyepiece when you hold the binocular up for viewing with the temperature gradient between your binocular and your body.
 
Last edited:
Face mask, take it off when viewing of course. I do hope you are not required to wear it in the house.:oops:

Jerry
 
Hi - thanks for all your replies. I am not wearing a mask and have also tried again all positions of the eye pieces including winding the eye pieces right down. It unfortunately makes no difference. Looks like it down to design and my eyes. But I still find it strange I have not experienced this before to this degree. My only other thought is to get hold of another paid of alpha bins and try in the same conditions before I decide whether to persevere with the NL's. Thanks again.
 
How do you clean the eyepiece? Maybe your method leaves some residue that increases the likelihood of condensation. Maybe try diluted shampoo or alcohol...
 
Hi, the bins are brand new and I have never cleaned the eyepieces, they look pristine to me.

I have heard back from Swaro who have suggested I return then to the dealer and try another pair to check if the particular pair I have are at fault. They don't have any ideas to offer on why they might be misting tho and don't have any other reports of similar so this looks like a long shot.

To try and reach some conclusion I have sourced a new Zeiss SF 10 x 32 to compare. Testing them in exactly the same conditions they showed absolutely no condensation build up, even after 5 minutes continuous use. The NL's started misting after 30 secs. The mystery deepens.

I do now have a direct comparison between the 2 and it will be decision time at the weekend.
 
it’s certainly worth a try to see if the issue is present with another NL. That is a shame if it is a personal incompatibility. :(
 
There is absolutely NOTHING wrong with your binocular , this type of condensation is normal , when the binocular warms up the "problem" will resolve itself.

Don't fret "the small stuff".
:)
Cheers.
 
This is normal for any binocular if you don't wear eyeglass. It depends on the temperature of your binocular. If the binocular is cold (approx less than 10 degrees C) the moisture from your eye will condensate on the eyepiece. On cold mornings I alway warm my binocular on my chest to reduce the effect. Having your eyecups set shorter than normal will improve ventilation between your eye and the eyepiece.

These are the best measures I've found myself when I have had this problem - certainly much more useful than "take a break until the weather improves" as suggested by the Nob from ND...

But (to the OP), if the NL keeps having this issue no matter what you do, and others don't, I'd ditch it. Good though it is, it's unlikely to be so good as to be worth the trouble all through the colder months.

I was wondering if anyone else has had a similar experience...

I have, when using old porros that cannot be used with glasses because they must be placed close to the eye. With glasses friendly designs like your NL, no (but, like RudiJG1 I use glasses with my binoculars if I can). But others have - as this (ahem) memorable thread discusses... Victory SF: Condensation on ocular lens
 
Thanks for the number of constructive thoughts and link to a previous post of a few years ago.

I tested the NL's in real world birdwatching over the weekend vs some new SF's in 10x30 and 8x30. Unfortunately the NL misted many times to a degree that the ability to see birds clearly was compromised. Mainly when in cooler conditions, when I was warm (after vigorous walking) or when viewing from indoors. The SF's did not mist once in the same conditions. I also don't ever recall my EL's missing either in similar conditions. Equally unfortunate was that (in my opinion) the NL's were superior in many ways. I so really wanted them to behave!
Anyway - I have sent all back and agreed with my supplier (who have been excellent) that once they get a new pair of NL's in I will test again to ascertain once and for all whether it was an issue with the sample or the design. If design I fear I may have made my task of finding my next binocular that much harder having seen what the NL can offer.
 
I took delivery of a pair of NL pure 10x42 last weekend. I am thrilled with them in every way bar one concern.

I have noticed that they are particularly prone to condensation forming on the eyepieces. This is external and starts forming after about 45 seconds of continuous viewing. I can see it disappearing as soon as I take the bins from my eyes and it goes after about 10 seconds. The left eye piece seems more prone than the right, it happens every time when viewing from inside my house and looking outside. It happens only sometimes outside, but more regularly when its cooler. My wife tried the bins inside and it happened to her also.
I can't remember this happening at all with the pair of 8.5 x 42 SV's I had for the past 6 years and it does not happen with an old pair of Zeiss I have. I tried every eye relief adjustment on the NL's and it makes little difference. The bins are stable at room temperature when I use them inside. I have also even checked the removable eyepieces with a spare set of SV and there seems to be little difference in size/shape or eye relief. The SV eyepieces don't fit the NL so I can't test in situ.

Swarovski say that as it's not internal then the bins are not at fault.

I was wondering if anyone else has had a similar experience or if there are any solutions I am missing. It seems very odd given I have not noticed before with other bins. I am loathed to keep the bins if this is a feature that I would have to live with. Any ideas welcome. Many thanks
I had exactly the same problem with a pair of 8X42 NL Pure that I purchased at the beginning of September only it was the right eyepiece that kept misting up. It was particularly bad in the field at temperatures below 4 degrees and rendered them useless. I took them back to the retailers and after experimenting with them and getting the same results, they sent them back to Swarovski who eventually said that a seal had been compromised on that barrel (and I therefore assume that the gas has been lost but I wasn't entirely convinced). This all took a lot of time and I had already lost confidence in the binnoculars and the dealer refunded me. As you wrote, they are optically stunning, but I personally couldn't justify spending over two grand on a pair of bins that become unusable in cool temperatures.
 
Wow, this is weird. The same thing happened with my 10x42 NL Pures (which I returned due to a faulty focusser) - although I didn't report on it because I just assumed it was normal.

During long glassing sessions, I sometimes held my breath to reduce condensation...as silly as that sounds.
I convinced myself that I was breathing too rapidly, or heavily, and that the binos weren't at fault.

My guess is that Swarovski was in a bit of a rush to get NL's out the door, and perhaps a few escaped quality control? One can only speculate.

There are plenty of people who have had nothing but positive experiences with their NL's, which suggests to me that the design itself is relatively sound.
 
Wow, this is weird. The same thing happened with my 10x42 NL Pures (which I returned due to a faulty focusser) - although I didn't report on it because I just assumed it was normal.

During long glassing sessions, I sometimes held my breath to reduce condensation...as silly as that sounds.
I convinced myself that I was breathing too rapidly, or heavily, and that the binos weren't at fault.

My guess is that Swarovski was in a bit of a rush to get NL's out the door, and perhaps a few escaped quality control? One can only speculate.
I am of the same opinion: a number of NLs have passed Swaro's QC despite some manufacturing defects. I am attaching 3 photos of the bridge of one of my NLs. The defect is obvious, the cause is less clear but look at the 3rd pic for a possible explanation---can you see the problem? Selling binos with manufacturing defects is rather atypical for Swaro, I'd guess the reason was a combination between the rush to get the NLs out the door and the effects of the pandemic.
 

Attachments

  • a.jpg
    a.jpg
    136.1 KB · Views: 172
  • c.jpg
    c.jpg
    142.9 KB · Views: 168
  • d.jpg
    d.jpg
    144.2 KB · Views: 170
I took them back to the retailers and after experimenting with them and getting the same results, they sent them back to Swarovski who eventually said that a seal had been compromised on that barrel (and I therefore assume that the gas has been lost but I wasn't entirely convinced).
I've been scratching my head for this whole thread. I occasionally encounter fogging but always bilaterally, presumably from my own eye moisture at some critical humidity/temp (generally around 40 F), possibly also involving how tightly the eyecups happen to be against my face. How could it involve gas purging -- isn't that meant to prevent condensation internally?

Sadly this may not be the best time to buy Swaro in any case. They must be understaffed, and are far behind in stocking dealers. Perhaps this is also why some units are showing "visible seams" while others aren't?
 
There is nothing that will stop or prevent condensation from happening on the outside of lenses. It is a matter of physics. When a surface is cold and warm air hits it moisture will condense on it. The design of the binocular has nothing to do with it nor does nitrogen purging the inside of the binoculars. Nitrogen purging prevents internal fogging. If your getting fogged up external lenses it is NOT because there is something wrong with your Swarovski NL binocular.

"Anhydrous (no water) gas like argon or nitrogen is purged inside the barrels of optics to remove moisture, mainly oxygen, and contaminants found in the air we breathe. Why? Optic companies do this to prevent internal fogging and create a clean moisture free non-corrosive environment between the lenses creating fog proof properties for the binocular or scope. That’s it! That being said, if your binocular/spotting scope/monocular/camera is moved into an environment with a sudden temperature change, you will experience instant fogging/condensation on the outside of the lenses. Nitrogen and argon purged binoculars will not deter external fogging. It’s best to acclimate your optic to the outside temperature before viewing. Here in Florida, I often pull off the road when I spot a less common bird. The latest was an American Kestral and Loggerhead Shrike pair. After pulling the binoculars out from the air-conditioned car, bam, instant fog on the outside of the lenses. Argon vs nitrogen purged binos doesn’t matter here because you can’t really just wipe away the condensation, it will just reappear, the binoculars must acclimate."
 
Last edited:
Warning! This thread is more than 3 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Users who are viewing this thread

Back
Top