Poll: does NL glare depend on eyeglasses? (1 Viewer)

[Troubador]

Well, it was a rather small sample (32), and other limitations of such a poll have been justly pointed out, although I see no reason to expect extraneous factors (weather, use habits, etc) to correlate much with wearing specs or not.

Its not so much a question of correlation. If a substantial number of spectacle wearers report no problem with glare, but actually they were all using their binos under cloudy skies when glare is unlikely anyway, this gives a false result.

Lee

 

[tenex]

Why would spec-wearers be more likely to have cloudy skies? (Unless you mean just a weird coincidence, but that comes under sample size.)

 

[Troubador]

Why would spec-wearers be more likely to have cloudy skies? (Unless you mean just a weird coincidence, but that comes under sample size.)

Ha! Of course you are right that considered globally, there is no reason spec-wearers should be more likely to have cloudy skies, but there are many parts of the world where cloudy skies are normal and not weird at all, and other places where cloudless skies are normal too, so, yes, it comes down to sample size. The larger the sample the more likely the weather conditions will 'average-out'. The same applies to sunny skies too and even the direction of viewing.

My point is that these factors strongly influence the likelihood of encountering glare and without controlling for these it seems difficult if not impossible to know how much or how little glare might be due to wearing spectacles.

Lee

 

[Richard D]

We'd need a much larger sample size to draw any real conclusions - there might even be variations in lens shape - If the curvature of the lens makes it harder to perfectly centre the pupils, that could be a cause for flare. I can't comment in depth on the NLs because whilst I've used them I don't currently own a pair, but with the EL 32's I only get flare if I try and look down with my eyes rather than moving the binoculars.

 

[Troubador]

We'd need a much larger sample size to draw any real conclusions - there might even be variations in lens shape - If the curvature of the lens makes it harder to perfectly centre the pupils, that could be a cause for flare. I can't comment in depth on the NLs because whilst I've used them I don't currently own a pair, but with the EL 32's I only get flare if I try and look down with my eyes rather than moving the binoculars.

Richard I see exactly what you mean but please allow me to be pedantic and point out that spectacles don't cause glare (which is reflections off surfaces within the binoculars) but they might indeed influence how likely you are to see it. I am think especially of the fact that folks who don't wear glasses have their eyesockets to help place the eyecups in front of their eyes whereas spectacle wearers have to position their binos on two glass lenses with no such guiding structures. Certainly when using the NL 8x32 I found the position of the binos relative to the eye most definitely influenced the extent of the glare I saw.

Lee

 

[Dennis Mau]

This was an interesting post by aznuge over at Cloudy Nights where he tested various binoculars for zones of glare. The NL's were the worst and the porro's the best. 1st attempt I have seen at testing and quantifying glare.

"I guess I have had a little too much time on my hands during the recent cloudy nights in Arizona. Here is some follow up on my glare tests. This was driven out of curiosity about glare in my NL Pure's. Yes, of all the binoculars I tested (6) ALL had glare, and all the glare could be eliminated with a shroud. I have now conducted new tests with more control and quantification of glare than the rough check done earlier. In the new ones, I have explored glare in a radial pattern about an LED light source in a darkish room. The purpose was to establish a "zone of glare" for each set of binoculars under these admittedly very harsh conditions. The pattern involved approaching the light source with each binocular from eight radial directions from 5 meters away. The room had been marked in increments of 5 degrees from the light source along these radial arms out to 45 degrees (as viewed from 5 meters away). When observing, I recorded the first significant appearance of glare along each direction, moving toward the light source origin. I repeated this testing in three sessions, on different days, with the same same binoculars.I averaged and charted the data. The results were interesting. I could establish a unique "zone of glare" for each pair of binoculars tested under these particular conditions. Here are the important comparative trends:

• The grand averages of the zones, by binocular, ranged from 19.8 to 38.3 degrees.
• The order of largest to the smallest zones was NL 8x42 > NL 12x42 > Maven 15x56 > Nikon 7x50 SP > Canon 10x42IS > Fuji 10x50.
• The roofs had symmetrical zones of glare about the light source; whereas the porros were a little asymmetrical.

What practically does this mean to me? Not much really. I do understand more fully now what the potential for glare behavior there is in my binoculars under extreme conditions. With that, I'm not about to send any instruments back to the suppliers for glare remediation. It's more of a personality trait than a defect, I believe. And in the field, it is not so easy to encounter glare. I'll give an example. The other night I was spotting a doubles location near the moon with my cherished NL 8x42s to set up for honing in with the big APM 100BTs. Searching very near the moon and gazing at the moon itself, I could see not glare in the NL's. The point source was very bright, but the surrounding background was pretty bright as well - not enough contrast to see glare. But I intentionally dropped 30 degrees or so to a dark background of trees, and then I could see a crescent of glare in my FOV opposite the moon. No surprise. I suppose I could have seen glare in any of my binoculars as long as the angle from the moon was within their zone of glare. I am still thinking about why glare varies among these particular binoculars the way it does. My first thought is that actual field of view is the dominant variable. But the Maven's with the least (4.5) are right up there with the NL's for glare. And the 12x42 NL's are not in the same lower zone as the Canon's and the Fuji's, even though they have the same FOV (6.5). Any ideas would be much appreciated. I think you nailed it. The roofs cluster together in FOV order. and so do porros together with Canon. I am showing charted data below to help illustrate:

 

[GrampaTom]

Richard I see exactly what you mean but please allow me to be pedantic and point out that spectacles don't cause glare (which is reflections off surfaces within the binoculars) but they might indeed influence how likely you are to see it. I am think especially of the fact that folks who don't wear glasses have their eyesockets to help place the eyecups in front of their eyes whereas spectacle wearers have to position their binos on two glass lenses with no such guiding structures. Certainly when using the NL 8x32 I found the position of the binos relative to the eye most definitely influenced the extent of the glare I saw.

Lee

Well, not my experience. Eyeglasses can and do permit, maybe even cause glare. I once had a pair of so-called rimless glasses with the lens edges polished. Sort of cool look, until I realized light was bouncing off that polished surface somehow and showing up as glare on my glasses, where I looked. I don't do polished edges any more. Shiny frames can also cause light to bounce on the lens. The eyeglass lens has 2 surfaces from which to collect and transmit reflection/glare. Opticians do sell anti glare coatings, surely you know this. We deal.

I know some here think glare, especially NL glare is an objective fact. My experience is too limited to say no, though I have yet to see it in my few quick looks. I also get that many think glare is an objective thing from within the bino do to Henry's flashlight experiments. I wonder. I collected flashlights for awhile before I came here. Now if you want to have some fun.., go read Candle Power Forums. You think we go a little bonkers? But that experience raises some questions I might ask of Henry. Bino designers design binos to work for most people in most conditions under which they can figure people will practically use them. I dont recall ever seeing instructions that said one should shine a flashlight into the big lens and point the small at a wall. Just sayin. But, what if that unusual usage, with that unusual, non natural light source is in fact making glare? Lumens, Candela, Frosted lens, clear lens, multiple LEDs, LEDs from this maker or that, all produce different light down range. What happens when we dont control or select for THOSE differences when we use so-called objective means to prove a bino has glare? Im truly sorry Henry if you did and commented on that in your early writings here.

So Lee, we know you see this peculiar kind of glare, and join a couple others here promoting your observation. But that seems rather more, subjective then objective. If That's correct and I fully acknowledge it may not be, I dont think we can say unequivocally "spectacles don't cause glare (which is reflections off surfaces within the binoculars)" We need to know more before we blame the tool. My Dad, used to say "its a poor craftsman who blames his tools."

 

[GrampaTom]

This was an interesting post by aznuge over at Cloudy Nights where he tested various binoculars for zones of glare. The NL's were the worst and the porro's the best. 1st attempt I have seen at testing and quantifying glare.

"I guess I have had a little too much time on my hands during the recent cloudy nights in Arizona. Here is some follow up on my glare tests. This was driven out of curiosity about glare in my NL Pure's. Yes, of all the binoculars I tested (6) ALL had glare, and all the glare could be eliminated with a shroud. I have now conducted new tests with more control and quantification of glare than the rough check done earlier. In the new ones, I have explored glare in a radial pattern about an LED light source in a darkish room. The purpose was to establish a "zone of glare" for each set of binoculars under these admittedly very harsh conditions. The pattern involved approaching the light source with each binocular from eight radial directions from 5 meters away. The room had been marked in increments of 5 degrees from the light source along these radial arms out to 45 degrees (as viewed from 5 meters away). When observing, I recorded the first significant appearance of glare along each direction, moving toward the light source origin. I repeated this testing in three sessions, on different days, with the same same binoculars.I averaged and charted the data. The results were interesting. I could establish a unique "zone of glare" for each pair of binoculars tested under these particular conditions. Here are the important comparative trends:

• The grand averages of the zones, by binocular, ranged from 19.8 to 38.3 degrees.
• The order of largest to the smallest zones was NL 8x42 > NL 12x42 > Maven 15x56 > Nikon 7x50 SP > Canon 10x42IS > Fuji 10x50.
• The roofs had symmetrical zones of glare about the light source; whereas the porros were a little asymmetrical.

What practically does this mean to me? Not much really. I do understand more fully now what the potential for glare behavior there is in my binoculars under extreme conditions. With that, I'm not about to send any instruments back to the suppliers for glare remediation. It's more of a personality trait than a defect, I believe. And in the field, it is not so easy to encounter glare. I'll give an example. The other night I was spotting a doubles location near the moon with my cherished NL 8x42s to set up for honing in with the big APM 100BTs. Searching very near the moon and gazing at the moon itself, I could see not glare in the NL's. The point source was very bright, but the surrounding background was pretty bright as well - not enough contrast to see glare. But I intentionally dropped 30 degrees or so to a dark background of trees, and then I could see a crescent of glare in my FOV opposite the moon. No surprise. I suppose I could have seen glare in any of my binoculars as long as the angle from the moon was within their zone of glare. I am still thinking about why glare varies among these particular binoculars the way it does. My first thought is that actual field of view is the dominant variable. But the Maven's with the least (4.5) are right up there with the NL's for glare. And the 12x42 NL's are not in the same lower zone as the Canon's and the Fuji's, even though they have the same FOV (6.5). Any ideas would be much appreciated. I think you nailed it. The roofs cluster together in FOV order. and so do porros together with Canon. I am showing charted data below to help illustrate:

View attachment 1449185

Denco, pretty cool find. I like his questioning style and conclusions most of which acknowledge the extreme "tests" we talk about dont zactly impact normal real, intended, use and when glare is there, its not the major thing some make it out to be. Its very interesting he, like Tenex, went looking for a correlation,Tenex/eyeglasses, this fellow/ FOV. We need to know more.

 

[henry link]

I know some here think glare, especially NL glare is an objective fact. My experience is too limited to say no, though I have yet to see it in my few quick looks. I also get that many think glare is an objective thing from within the bino do to Henry's flashlight experiments. I wonder. I collected flashlights for awhile before I came here. Now if you want to have some fun.., go read Candle Power Forums. You think we go a little bonkers? But that experience raises some questions I might ask of Henry. Bino designers design binos to work for most people in most conditions under which they can figure people will practically use them. I dont recall ever seeing instructions that said one should shine a flashlight into the big lens and point the small at a wall. Just sayin. But, what if that unusual usage, with that unusual, non natural light source is in fact making glare? Lumens, Candela, Frosted lens, clear lens, multiple LEDs, LEDs from this maker or that, all produce different light down range. What happens when we dont control or select for THOSE differences when we use so-called objective means to prove a bino has glare? Im truly sorry Henry if you did and commented on that in your early writings here.

Tom,

I don't recognize any of my ideas or methods for observing glare in that paragraph. Perhaps you're confusing the photos I posted of the NL's internal reflections with the "flashlight" method for measuring the clear aperture of a binocular, which I've also posted.

Here's one of my old posts showing the internal reflections that cause glare in the 8x42 NL.

Swarovski NL 8x42 - First Impressions

The usual difference that one would expect as the magnification increases: I had the 8x42 and the 10x42 and the latter was worse---the larger EP of the 8x42 makes eye placement easier. So apparently the large FOV has little to do with the glare problem, as speculated by some, since the glare...

www.birdforum.net

I don't have any more to add to the subject. I considered it a settled matter over a year ago.

Henry

 

[GrampaTom]

Tom,
Perhaps you're confusing the photos I posted of the NL's internal reflections with the "flashlight" method for measuring the clear aperture of a binocular, which I've also posted.

Ah! I bet, yes, thanks