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Zeiss HT 8X42 dazzling flare spots (1 Viewer)

mulligatawny owl

Well-known member
Anyone else get this? Awesome binoculars in just about every other way but I find the internal flaring quite distracting on occasions.

I don't know if it's a side effect of their amazing brightness but I've never encountered a binocular that has such bright pinpoint spots of flare, almost like a purple Lazer beam point of light right in the field of view.

I get this whether I use them with my glasses or contacts. The only remedy seems to be sheilding the eyecups against the low sun with my hands.

Anyway, just curious if anyone else has found the same problem or a solution to it.
 
This problem is quite different from the glare we usually discuss since it happens when sunlight coming from behind the observer leaks between the observer's face and the eyecup and sends a tiny reflection of the sun from one or more eyepiece glass surfaces directly back into the eye. It's more likely to happen if the eyelens of the eyepiece is wide, and/or the eye relief is long, the eyecup is shallow and/or the observer's face is narrow. Eyeglasses make it harder to avoid since the eyecups have to be used in the down position.

I'm surprised you don't have the problem with other binoculars, since the 8x42 HT doesn't have a particularly wide eyelens or especially long eye relief. Winged eyecups can help or even completely eliminate the problem if they seal well against the side of your head. I use the Field Optics Research Eyeshields for standard sized binoculars on some Zeiss binoculars with the same size eyecup as the 8x42 HT, but they don't form a complete seal for me.

Henry
 
Thanks Henry, I might have to invest in some eyeshields for when I'm wearing contacts, I mostly wear glasses though so not an ideal solution.
I have indeed found similar flaring on other bins, each seems to flare in a slightly different way, but the HT just seems particularly bright and pinpoint and purple.
I guess once the mind has fixated on something in an otherwise flawless view it's hard to learn to ignore it.
 
MO
You might try checking to make sure your specs are sitting as high up your nose as is comfortable so they are as close to your eyes as can be. It may be that closing the gap between your face and the eyecups just a tiny bit might make all the difference.

I wear specs and have not seen this phenomenon with my HTs.

Good luck.

Lee
 
I use the HT with the eyecups mostly down [MOLCET], often exposed to the sun from behind, and never get this problem. I do see it a bit with a 10x42FL but not the HT and find the AR coatings seem more effective in suppressing reflections.

I've gone out of my way, messing about in the field with various view angles etc., to see if the HT eye-lenses produce reflections and have not yet been able to produce the effect.

Now, if the problem was crescent flare from in front I would suggest adjusting your IPD, as I find a too narrow IPD moves otherwise harmless flares back into your FOV, at least in my case.

I've said it before and will repeat - my HT, when properly set up in terms of IPD and eye-cup position, is glare / flare free....apart from veiling glare from extremely bright light sources, which seems impossible to completely control, no matter the bino.
 
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Thanks Lee and James.
I've tried various glasses/ eyecups adjustments and the problem seems to stubbornly not go away. Must be a combination of things regarding glasses, face shape etc. causing it.
The peculiar thing is how bright and pinpoint the flare is, on my SE's for example the flare spots when they do arise, which is much less often,are much more diffuse and less distracting.
It's a bit of a mystery to be honest.
 
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Does this happen only on bright sunny days with sun somewhat behind and to one side as suggested by Henry's explanation?

Lee
 
Lee, I've only had them for a few weeks and am not familiar with them in all conditions to say for sure but yes it's mainly when the sun is behind and to one side, not necessarily that low.
 
Pull your eyes back slowly from the eye-lens when you see the flare - you should be able to identify the source. If it's coming from the eye-lens itself, it should have a magenta or orangey tone.
 
The size and intensity of the solar reflections depend on whether the glass surfaces, probably the rear eye lens surface is flat or curved.
There could possibly be reflections from more than one surface, giving different sun glints.

The colour is probably due to coatings or combinations of coatings maybe if some are from internal eyepiece surface reflections.

If the rear of the binocular and also the observer are in the shade of say a tree, direct solar reflections won't occur.

If the sun is very high I suppose it might also not happen.

So these reflections can be avoided even on sunny days by careful positioning.

There could be lesser reflections from the sun's reflection from windows. Usually 25 times less bright.

We don't have these problems often in Britain.
 
Thanks James, will try that when the sun finally decides to show itself again here.

Thanks for the explanation Binastro.

I think I'll try using a different pair of glasses when I use them next and also experiment with different eye positions and IPD both with and without glasses.

It's not really a huge deal or anything but it's something I noticed almost right away with the HT's and it struck me as something I've not experienced before in quite this very particular manner. I've owned more bins than I care to admit too, and as far as I can recall most flare is more diffuse and at the edge of the FOV not quite this bright pinpoint closer to the centre.
I should say that I have on a couple of occasions seen the more familiar diffuse flare in the HT also but not found it distacting.

Anyway, I'm not blaming it on the HT's themselves, as I said earlier I guess it's probably just a combination of factors regarding glasses, face shape etc. but I do wonder if the very bright pinpoint nature of the flare is related to their very high transmission?
 
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If the phenomenon is caused as described by Henry as seems likely, the light is being reflected off the top surface of the eyepiece (although there could also be reflections off one or two lens surfaces below the top one) so the light is hardly traveling through enough HT glass for it to influence what you see and if the reflection is only off the top surface it is not traveling through any glass at all.

When it happens again, if you lift your hand on your 'sunward side' and use it to cover the gap between your face and the eyecup on that side then the reflection should disappear. Your binos won't be as steady as they can be when you do this but it would at least tell you for sure if the reflection is being caused in the way we suspect.

Lee
 
Try wearing a soft hat with a nice wide brim. If the sun is intruding too much from the sides or back, just adjust the brim to block it.
 
Well, the sun finally showed itself today so I had an hour out to test the HT's. The bad news is I forgot to take my hat (sorry peatmoss) or my other binoculars or my other pair of glasses...the good news is that I'm sure the problem is mainly a glasses problem.

Contrary to what I said earlier I couldn't get the flare to happen this time without my glasses whereas it was pretty apparent with them on. Also contrary to my earlier statement it appears to happen with the sun somewhat in front of me rather than behind ( normal type flare spots were noticeable with sun behind)

Strange that I've not had this problem before that I can recall with other binoculars but still I feel like a bit of a dunderhead for rattling off a thread on the subject before getting my facts ( or my glasses) straight.
 
Just a further update for anyone interested.
I've found this 'problem' has persisted whatever glasses I wear and is still somewhat evident without glasses. Fortunately wearing a wide brim hat as suggested pretty much cures it completely :)
 
So if I see a guy carrying a pair of HTs at Bird Fair and wearing one of those huge Mexican hats, that will be you then will it?

Glad to hear you have got on top of this issue and it looks like you owe Peatmoss a coffee........

Lee
 
Just another little update for those who might be interested.

I recently acquired some SF 8X42's and these work far better for me at controling glare and flare. In the same situation as the HT they show none of the flare problems I described in the original post. Unfortunately I'm not entirely convinced they are a superior binocular in other ways but I'll leave that for another post!
 
Just another little update for those who might be interested.

I recently acquired some SF 8X42's and these work far better for me at controling glare and flare. In the same situation as the HT they show none of the flare problems I described in the original post. Unfortunately I'm not entirely convinced they are a superior binocular in other ways but I'll leave that for another post!

From the description in your first post, it sounds like it might be specs of dust on the (ocular)lenses. I have seen this occasionally in bins as well.

Eye cups might be a bit shallower on the HT:s as well making them a bit more sensitive to stray/side light to the eye piece.

That the SF would handle glare and flare better than the HT is interesting, as the SF seem to suffer from occasional crescent flare in some difficult light situations. Both bins seem to be pretty good in most cases though.
 
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From the description in your first post, it sounds like it might be specs of dust on the (ocular)lenses. I have seen this occasionally in bins as well.

Eye cups might be a bit shallower on the HT:s as well making them a bit more sensitive to stray/side light to the eye piece.

That the SF would handle glare and flare better than the HT is interesting, as the SF seem to suffer from occasional crescent flare in some difficult light situations. Both bins seem to be pretty good in most cases though.

No specs of dust as far as I could see on the occulars, I'm quite handy with the blower too.

Talking of dust my SF's (bought used) have a shocking amount of internal dust in one barrel.
 
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