38 replies to this topic

[drt3d]

I see the subject of glare in the Swarovski NL Pure line has already been discussed, but maybe this is something new.

 

I got my Swarovski NL Pure 8x32 this week and I noticed the glare right away, when viewing against a bright source of light (could be the open sky) a bit off the axis.

One thing I noticed, and I don't see it mentioned, is that the left side shows considerably more glare than the right side.

 

Last night I was in my living room in total darkness, except a few "Christmas lights" hanging on the bookcase across the room. As I was checking the binoculars out, I noticed that at a certain direction I could see the reflections of these lights on the left side only. I could see distinct lights reflected, moving in and out, as I was moving the binoculars. This was happening when the lights were about 20 degrees (my estimate) to the right. Using my hand to block a bit this side, would make the reflections disappear.

 

If I can see the distinct points of light reflected, obviously I can see the entire bright sky reflected and causing glare galore, on the left side only. The right side also shows some glare but not as bad as the left side.

 

Has anyone noticed anything like that?

 

Are my binoculars defective?

 

I was planning to make shades over the oculars, something that I really should not have to do when using such an expensive pair of binoculars.

By comparison, I also got a pair of Nikon 8x30 EII, and these show no glare at all.

 

George

Edited by drt3d, 10 October 2023 - 12:07 PM.

[pat in los angeles basin]

I would flip the binos over - using the right tube to the left eye and repeat the experiment to determine if the artifacts are strictly limited to the one side. Pat

[exup]

https://www.birdforu...onsters.445008/

 

This is another tedious thread from BF, but there seem to be reports of Swaro NLs displaying glare. One of the later posts found it was possible to modify eye position & orientation that mitigated it. 

TBD if yours could benefit as it sounds rather specific in your case.

I don't have NLs, so can't comment from experience.

[Erik Bakker]

Sorry to hear that George.

 

Individual fit of the eyes and face of the observer to a binocular is an important factor in this. That said, many Swaro’s are prone to veiling glare. My Habicht 8x30 porro suffered from that very substantially for me. Making it hard to use and enjoy with brighter skies above the object of interest, especially during dusk and dawn. And none of my Swaro’s liked a half full or fuller moon in the outer parts of their fields. My NL 10x42 also suffered from that and some veiling glare, but I could mitigate that a bit at times with repositioning my eyes carefully.  In the end, I sold all my Swaro’s, in part because of the glare issues, but they also do have wonderful strong points, so if those matter more/most and the glare is not much of a personal bother, owners are vey happy with their Swaro’s. The SLC 56’s do better in that respect, as does the 7x42 Habicht porro.

[GlennLeDrew]

Here's something to consider. Outside of the exit pupil are partial false pupil sections. If they are sufficiently close to the central pupil, and or your iris is wide open, and/or you allow the exit pupil to shift laterally w.r.t. to your iris, such a false pupil can admit its unwanted light through your iris.

 

I fairly strongly suspect this is the main issue.

Edited by GlennLeDrew, 10 October 2023 - 11:23 PM.

[pat in los angeles basin]

Glen, could that be caused by a slight miss setting of the IPD? More accurate eye placement as a partial remedy? Or simply a feature of the optics= live with it.  Pat

[aznuge]

Just chiming in since I have the 8x32 and haven't noticed any asymmetrical glare.  Also, I have not tested it yet for the magnitude of veiling glare like I have the NL 42 series. But if it is true to form it will have glare sensitivity that is among the highest in my collection - seems to be a personality trait of the NLs; but one I can live with while still enjoying their other, highly positive features.

 

This could very well be a defective unit.  If it were me I would follow Pat's advice and flip the binocular to see if the glare asymmetry changes or remains the same. Then send it in for replacement or repair if the more intense glare is barrel-centric.

[pat in los angeles basin]

aznuge; Was there a way to minimize the glare in the NL8x42 or did you live with it.  Pat

[aznuge]

I live with it

[Binojunky]

Not wishing to be critical as I own a Alpha binocular from the company in question, how on earth do defects either in build or design get past the QC department ?, at the prices charged they should be ashamed of the fact, I guess its like most things nowadays, grab the money and run for the hills. I ran into a similar problem on an expensive premium binocular a few years back, proudly proclaiming lots of eye relief for glasses wearers when it fact only 90% of the FOV could be seen, Dave.

[aznuge]

I have never had a defect in a Swarovski product and I own my fair share.  I wouldn't call glare in the NLs a design defect, but it seems to me that some glare is the compromise for the wide field.  For me it is not a show stopper, I rarely see glare in them when in use.  I feel I have characterized the NLs to a level that I understand their potential for glare, and have quantified it in my own way.  I would buy them again. 

 

Every binocular I have tested exhibits veiling glare - its a matter of degree and personal tolerance.

 

The type of issue described by the OP seems unusual.  It may be from a factory defect.  All OEMs have defects and returns, its a matter of rate.  (And now I am curious what these rates are among optics suppliers...)  Then again, it may have been caused by previous wear and tear if the NL 8x32 in question was a "used" purchase.  Regardless, it should be able to be remedied I think.

 

Eye relief is a frustrating one.  I have also been let down by good ER numbers from a supplier only to find out I couldn't see the entire field of view with my glasses on. So now I rely on independent sources, such as Binoculars Today, to get the measured  "usable" eye relief. Also, Oberwerk now measures and self reports "usable" eye relief for their products.

Edited by aznuge, 11 October 2023 - 04:20 PM.

[drt3d]

Hi Guys,

 

I am a big Swarovski fan and I love the feel, sharpness and just about everything about this pair, except for the glare.

 

I bought them brand new at full retail price. I have them for a week. I enjoy using them, and the glare is only a problem in some cases. I agree that it is not a showstopper and, yes, I can live with it. Yes, all binoculars show some glare, but the amount of glare here is unprecedented. It is really a scandal. And we should say something about it.

 

Last night, my wife was watching TV and I was playing with the binoculars looking around the room. The big bright TV screen causes loads of glare. At some angle, very close to the TV but a bit to the side, I can see the TV screen. I can watch the show inside the binoculars, while my binoculars are pointing to the side of the TV. It's fascinating I compare them to the Nikon 8x32 EII. Totally different design, similar wide field of view, very minimal (almost non-existent) glare in the Nikons.  I tried using shades but the angle to the bright source (TV screen) is so steep that even a long shade cannot stop the glare. 

 

Instead of sweeping the issue under the carpet, I think Swarovski should address it and hopefully do something about it.

 

George

[aznuge]

Cool. I am going to try the TV screen test when I get home from traveling, and I’ll report back. I have the Nikon 8x30 EII as well.

[GlennLeDrew]

If I had one of these in hand to examine, I think it would take less than 60 seconds to determine if we're dealing with a coherent reflection passing through the exit pupil or if the cause is a proximate false pupil near the exit pupil. The fact of a ghost image being seen leads me to want to put the blame on the false pupil.

 

Set up the bino on a tripod, or devise a means to anchor it once a reflected image is seen during use. Then use a magnifier to examine the exit pupil and the false pupils. The indoors TV test is good for this, as the reflrcted image is unambiguous.

[Bkoh]

Glare seems to be an inherent "feature" of many 8x30/32 binoculars with a wide (8°+) field of view:

Swarovski NL 8x32
Swarovksi EL 8x32
Zeiss Conquest HD 8x32
Nikon Monarch M7 8x30
Kite Optics Lynx 8x30
Opticron Traveller 8x30

All have attracted comments and complaints about veiling glare on Birdforum.

My EL 8x32 also suffers glare around sunset, and at night from street lights nearby. Most of my birding is in the mid/late morning so it's not normally an issue, but it's there.

My non-8x32 binos, such as 8x42 Celestron Trailseeker and 10x42 Canon IS, do not exhibit noticeable glare.

Leica's 8x32 units don't seem to have many glare complaints, but their field of view is slightly smaller and eye relief somewhat shorter. So maybe the baffling or eyepiece design needed to cut out glare requires compromises elsewhere. Horses for courses, as it were. YMMV, my $0.02 etc.

[GlennLeDrew]

In order for a ghost reflection to be seen through the exit pupil and be superimposed upon the actual image, the path of reflected light must pass out through the exit pupil and remain within the field of view.

 

How to unambiguously determine this? Set up the bino so that some identifiable object outside the FoV of the instrument is seen as a ghost image. Such as a TV screen, as someone described earlier. Lock down the bino so that it cannot move; a tripod is good. Place a laser pointer at the position of the object whose ghost reflection is seen. Aim the laser into the relevant objective until its spot passes out through the eyepiece. If you can lock down the laser, good; if not, a lab assistant is needed. Determine if the laser light is exiting through the exit pupil or instead a false pupil segment. To verify that the exiting light path is indeed within the field of view, place a screen behind the bino, shine a flashlight into the objective so as to get a circle of field-filling light projected upon the screen, and note the position of the laser spot with respect to the circle's periphery.

 

Someone who can do this would provide a service to the community. I have no access to an NL Pure.

[cimar]

I've never had a flare problem with any of my Leica binoculars, including the 8x32 Ultravid.

[aznuge]

I remember the feeling I had when I first saw significant glare in my 8x42 NLs.  Pretty devastating - how could such high end bins show glare like this?!  It was late afternoon almost three years ago.  I was starting to observe birds at feeders in a tree in my back yard in a direction toward the northwest.  It was a cloudy day, so no direct sunlight.  But huge and intense glare (veiling glare as I now understand it) jumped into my FOV in an imposing fashion. The clouded over sun was in the range of 10 to 30 degrees off axis toward the west.

 

I wanted to understand this phenomenon better, especially after getting involved in this thread some months later. I wondered if any other of my bins would show anything like the NL 8x42s did in terms of glare.  So I decided on an artificial glare test that I could do at home.  It involved a darkened room, a point source of light, and mounted binoculars approaching the point of light from different angles, and recording the angle away from the source that glare first appears.

 

All the binoculars that I tested this way showed glare.  The angular range of this "zone of glare" was 20 to 38 degrees from the point source of light, the highest being the NL 8x42.  Although I didn't use lasers (intriguing idea), this point source test gave satisfying results in terms of establishing practical expectations for seeing glare in the field for a particular binocular.  And in practice it bears out fairly closely.

 

With the insight of ihf for the analysis, these trends were evident:  porros vs roofs group differently, with porros tighter and smaller for zone of glare (ZOG); within the groups, the wider the FOV, the larger the ZOG.  I'll show some detail in a little while...

[drt3d]

I just came inside the house from looking around the bird feeder at my deck. It is a cloudy / heavy overcast day.

 

There is noticeable glare at the bottom of the image, both sides, from the overcast sky at the top. Using my fingers to block the top, the glare disappears. I can get used to this and ignore the bottom glare and only pay attention to the center of the image, but it's a lot better without the glare.

 

So, l am thinking of making a pull in/out shade from black cardboard/paper, one for each barrel, to eliminate this type of glare. Pull out the shade to stop the glare, push it back in to close the lens caps.

 

George

[aznuge]

Follow-up for post 18 - here is the ZOG testing concept that I used:

 

 

This illustrates the pattern of detecting "first" glare for each of three sessions, across the 6 binoculars. Glare was noted at the first encounter where it had grown to about 1/4 of the FOV. It was usually in a crescent or half-moon shape on the opposite side of the FOV from the light source. Eight tests were done for each binocular per session, and there were 3 sessions. First glare was noted along each of the radial paths toward the light source to the nearest 5 degrees. The dark room for the tests was laid out with degree markers in advance in increments of 5 degrees, from 45 to 5, along the radial paths. Glare, once noted, always increased toward the light source. There were no exceptions.

[aznuge]

And these were the results for the first 6 binos tested:

 

 

The overall grand average for all results is 26.9. The order of the individual binocular averages, form largest to smallest "zone of glare" are these: Swarovski NL 8x42 > Swarovski NL 12x42 > Maven 5B 15x56 > Nikon 7x50 SP > Canon 10x42L IS > Fujinon FMT-SX 10x50.

[aznuge]

Some asymmetry was evident in the porros, and I'm not sure how to explain that:

 

[GlennLeDrew]

We need to be careful to differentiate between glare as resulting from light scatter off of interior surfaces and ghost reflections which are coherent images resulting from reflection off of flat, polished surfaces. These are utterly different phenomena.

 

The objective focal length (and to a degree the f/ratio) plays a role in the angular offset from which an out-of-field light source can illuminate the interior. Shorter f.l. objectives are nearer to the prism system, and so light can enter there from a larger off-axis angle.

 

The prism type and orientation of its various sides and faces has a bearing on the directions from which light is admitted to cause the most prominent of these unwanted light intrusions.

 

Prism systems are the leading source of scatter, reflections and ghosts. To control unwanted light prism apertures should be knife-edged or otherwise made to not introduce specular reflections. Prism sides should be ground and blackened.

 

A disadvantage of wide angle binos is the fact that the prism system-induced false pupils get nearer to the central pupil, other things being equal.

[aznuge]

This was admittedly a "harsh" test.  But life in the field can get harsh when pointing optics near a bright moon, the sun, stadium lights etc.  I have since tested a couple other bins, and plan to test more.  I have eased the testing regimen to just the two horizontal positions, left and right, assuming symmetry for the most part.  The ZOG values for the added ones are:  Zeiss Victory SF T* 10x42 - 23°; and Nikon SE 10x42 - 24°.

 

The relevance for this thread is that, in my opinion, binoculars can be be expected to show veiling glare under harsh conditions, its a matter of degree.  And the wide field NLs show stronger sensitivity to glare than narrower FOV binoculars.

 

The bins that I'm now curious to test for ZOG are the NL 8x32 and Nikon 8x30 EII (including the TV test  ), the Nikon WX 10x50, and one of the EDGs in 42mm.  The EDGs have been cited often as having no glare, and maybe their result be zero for this test, we'll see...

[gwlee]

 

So, l am thinking of making a pull in/out shade from black cardboard/paper, one for each barrel, to eliminate this type of glare. Pull out the shade to stop the glare, push it back in to close the lens caps.

 

George

All of my binoculars show some glare under some circumstances. Under those circumstances, I hold the binoculars nearer  the objective lenses so that my hands partially shield the objectives and reduce the glare.