Blackouts looking at edge of FOV with Noctivid 8x (2 Viewers)

[hopster]

As many of you here will know if you have seen some of my posts, I'm a big fan of the Noctivid as my favourite 8x42 because of the great (unique?) combination of colour balance and saturation, sharpness, contrast, focuser, glare resistance, panning behaviour, build etc. After having compared with everything I could get my hands on, I have owned a pair from new since August and have seen no other binocular that competes in terms of natural and vibrant colour representation in particular. I am not troubled by the occasional lateral CA which some mention because it is quite rare once you get your eye positioning just right. So why this post? Well, I am noticing something that is starting to trouble me a bit now. I should mention that I use them with glasses, so I will confirm whether or not this happens without but I don't see why it should be any different.

I have learned to carefully set the IPD (sometimes needs to be a little different for close and far viewing) and the ER where I use O-rings so that I can adjust it with 0.5mm precision if necessary and not rely on the eyecup stops. I have found this to be quite important - the NV seems more sensitive to eye position than most other 8x and 10x binoculars that I have used enough to get to know well.

When everything is set so that I can just see the field stop, I would assume that this is the correct distance away from the eyepiece glass and therefore far enough to avoid kidney beans/blackouts as I look around the FOV. But this does not seem to be the case because when I look to an edge of the FOV I very often get them, even on a relatively bright day when my pupil should be smaller. I have tried going closer but then it gets worse, and further away but then I lose some of the field. I'm not sure what else I can do. All I have to do to stop it happening is to move the binocular slightly relative to my eye and then it's fine; this also completely eradicates any residual lateral CA, by the way. Do other people have this same experience?

Am I perhaps being too fussy and any 8x42 with modern wide'ish angle eyepieces will do the same thing because of the finite exit pupil? Does everyone slightly move an 8x42 binocular (or NV in particular) relative to their eye to get a clear view of the edges of the FOV? If so, I should just stop worrying about it and enjoy the positives, but if there are other binoculars out there which allow me to roam the FOV more easily with just eye movements then I should probably at least know about them so that I could consider alternatives. If I do, I need the following:

• a waterproof 8x42 (or 7x42) roof which is well-built
• enough ER for spectacles
• good warranty and long-term service situation (so probably European built plus perhaps some Japanese)
• does not filter out the red end of the spectrum too much (so for me this means no Zeiss or Swaro unfortunately, unless I potentially consider SLC/Kahles Helia S)
• controls CA well in most of the FOV
• has a relatively fast and smooth focuser
• produces a good level of colour saturation and sharpness
• good resistance to glare

I am not bothered about a super-flat field or super-wide FOV, though if I get them I won't complain

The above requirements cut down the options pretty sharply to the following I think in, either 7x42 or 8x42:

• Meopta Meostar
• Leica UVHD+
• Nikon EDG
• SLC/Kahles Helia S

The Meoptas are not current models but there should be some second-hand around. The UVHD+ in 7x42 might be a nice choice if it has enough ER and controls CA at least as well as the NV. The SLC/Kahles Helia S (8x42 only) does filter out a little too much red for my taste and has a slow and slightly gritty focuser. The EDGs I have never looked through for any length of time and seem like a good possibility because I have heard very good things about focuser, colour balance, CA, ease of eye positioning (though opinions seem to differ between 7x and 8x?), glare performance.

Any other thoughts on this? I am particularly interested to hear from those who have (or had) the above binoculars and have been able to compare to the NV at some point.

Anyway this might be irrelevant if all of them will behave similarly to the NV in terms of blackouts looking at the edge of the FOV, so if this is likely then please just tell me straight and I'll either stop fussing about it and enjoy the NV for the great things it does do or else consider a 7x50 or 8x50 instead! Meopta do a nice 7x50 Meostar I believe, if I can deal with the extra heft.

TIA

M

 

[Maljunulo]

You need to fiddle with IPD and eyepiece extension.

 

[hopster]

You need to fiddle with IPD and eyepiece extension.

I have explored all the options pretty thoroughly, and precisely.

 

[dries1]

Hopefully others who wear glasses will chime in.

 

[Maljunulo]

I have explored all the options pretty thoroughly, and precisely.

Good for you!

So had I, until I finally got it right.

 

[Ratal]

Good for you!

So had I, until I finally got it right.

^^^ This. 100%.

Drove my brother absolutely demented at first - then he got them sorted. Its a very fine line to tread with the Noctavid.

 

[hopster]

I have to say to #5 & #6 that I have been using them basically every day since August, sometimes for several hours a day, in many different lighting conditions, and there are not that many variables to explore with ER and IPD until you have exhausted all their combinations. So if it's a fine line it may be a bit too fine to be viable. Must be something about my eyes or face. Unless the following...

What I'm most curious about is whether people also have this experience with other modern 8x42s, or if at the right ER and IPD some allow you to roam all over the FOV without moving the binocular at all. I used to do this easily in older 8x42s with narrower FOVs.

 

[hopster]

What I'm most curious about is whether people also have this experience with other modern 8x42s, or if at the right ER and IPD some allow you to roam all over the FOV without moving the binocular at all. I used to do this easily in older 8x42s with narrower FOVs.

I'm curious that nobody has answered this question yet, which is the core of the whole discussion. It would be easy to say "yes my XYZ brand 8x42 allows me to look at the edge of the FOV with no blackouts when I have the IPD and ER dialled in properly" - or the converse.

Does this suggest it that it may be a common issue but either not noticed or discussed very often?

 

[mskb]

Hi @hopster,

I used to have the issues you note before with pretty much all binoculars. This video helped me immensely in setting up the IPD and eye relief :

.

One other point: as far as I understand, binoculars are designed to be looked at the center of the FoV. So if something on the edge of the FoV catches your attention, instead of bringing your eyes to look at the edge (which may cause blackouts when the eyes' pupils fall partially outside the region covered by the exit pupil of the binoculars), move the binoculars so that the center is now aligned to the subject that caught your attention.

Cheers and happy viewing through the Noctivids!

 

[Maljunulo]

I'm curious that nobody has answered this question yet, which is the core of the whole discussion. It would be easy to say "yes my XYZ brand 8x42 allows me to look at the edge of the FOV with no blackouts when I have the IPD and ER dialled in properly" - or the converse.

Does this suggest it that it may be a common issue but either not noticed or discussed very often?

My answer is a qualified yes.

I can look around the field in my 8X32 SF, but not with the ease that I could with my 10X42 EL SV.

Almost, but not quite, and this after lots of fiddling, until I finally got it right.

In the beginning, it was a real nuisance.

I don’t think it has anything to do with field of view, but is related o the size of the exit pupil in relation to your entrance pupil. (I’m guessing here)

 

[Maljunulo]

Hi @hopster,

I used to have the issues you note before with pretty much all binoculars. This video helped me immensely in setting up the IPD and eye relief :

.

One other point: as far as I understand, binoculars are designed to be looked at the center of the FoV. So if something on the edge of the FoV catches your attention, instead of bringing your eyes to look at the edge (which may cause blackouts when the eyes' pupils fall partially outside the region covered by the exit pupil of the binoculars), move the binoculars so that the center is now aligned to the subject that caught your attention.

Cheers and happy viewing through the Noctivids!

Thank you.

You put that up while I was typing.

 

[hopster]

Hi @hopster,

I used to have the issues you note before with pretty much all binoculars. This video helped me immensely in setting up the IPD and eye relief :

.

One other point: as far as I understand, binoculars are designed to be looked at the center of the FoV. So if something on the edge of the FoV catches your attention, instead of bringing your eyes to look at the edge (which may cause blackouts when the eyes' pupils fall partially outside the region covered by the exit pupil of the binoculars), move the binoculars so that the center is now aligned to the subject that caught your attention.

Cheers and happy viewing through the Noctivids!

Thanks for the positive reply and the attempt to be helpful. Like some others though, it does assume that I don't know how or why to adjust IPD and ER. Nobody here knows my history (and why would they) so I should just say that I learned these skills many years ago (30?) and have done it on many binoculars since then.

This thread is an attempt to focus the discussion on modern 8x42 roofs with wide'ish angle eyepieces, and the NV in particular.

 

[Maljunulo]

Thanks for the positive reply and the attempt to be helpful. Like some others though, it does assume that I don't know how or why to adjust IPD and ER. Nobody here knows my history (and why would they) so I should just say that I learned these skills many years ago (30?) and have done it on many binoculars since then.

This thread is an attempt to focus the discussion on modern 8x42 roofs with wide'ish angle eyepieces, and the NV in particular.

No one is assuming any such thing. We are simply stating what we see as a possible reason for your difficulties, based on our experience.

Just because you have been doing something for n years doesn’t necessarily mean you are doing it right.

Kidney beans and blackouts result from incorrect eye placement, not some mysterious properties of a particular binocular. (my opinion)

 

[mskb]

Thanks for the positive reply and the attempt to be helpful. Like some others though, it does assume that I don't know how or why to adjust IPD and ER. Nobody here knows my history (and why would they) so I should just say that I learned these skills many years ago (30?) and have done it on many binoculars since then.

This thread is an attempt to focus the discussion on modern 8x42 roofs with wide'ish angle eyepieces, and the NV in particular.

My sincere apologies @hopster. Hope the thread catches more attention from other optics experts here, and that they are able to offer some clarity! Good luck with the research!

 

[dries1]

Hopster,

You were using them since August and everything was fine until present. Any changes that you could recall, different viewing conditions from then to now, etc? I am only asking why all of a sudden, August is three months past.

 

[PeterPS]

The keyword here is what's usually called the "eye box", which is a misnomer as it's not a box but rather a cone with the vertex toward the eyepieces and the flat base toward your eyes. The conic shape of the "eye box" means that when you get closer to the oculars the eye placement becomes more critical, and even a small misalignment (such as when you roam your eyes around in the FoV) can cause blackouts---you said that you "just see the field stop" thus you must be close to the oculars.

 

[Patudo]

When everything is set so that I can just see the field stop, I would assume that this is the correct distance away from the eyepiece glass...

I'm slightly hesitating to weigh in here, given the tone of your post #12, but here goes ...

I really like the effect you get when you can move the field stop "far out" as I would call it - it gives you the oft mentioned "open window" and in general makes for a more pleasant viewing experience. But this is normally achieved by moving the binocular closer to your eyes and when you get too close, blackouts start to happen. Some binoculars allow me to move the field stop further out than others, but - certainly with the more modern ones with longer eye relief - there comes a stage that blackouts happen with all of them.

I get the feeling when reading your original post that your eyes are just a little too close, so that blackouts are only appearing at the edges of your field of view rather than across the whole image. My recommendation would be (not to teach you to suck eggs, but...) to extend the eyecups very slightly until the edge blackouts no longer happen. You will not lose actual field of view (this can be easily checked against landmarks) unless and until you move your eye back beyond the binocular's eye relief figure, which should not happen as we are talking very slight adjustments here and the Noctivid range have pretty generous eye relief.

In terms of modus operandi when observing - I am myself of the school that looks around my field of view to find things, rather than re-centering my field of view on everything I want to look at - I only do that when something of real interest is seen. I don't move my binocular relative to my eyes to get a clear view of the edges of the FOV - I aim to have set the eyecup distance up so that the entire FOV is accessible. FOV of my regular 8x42 (Zeiss FL) is I believe the same as your Noctivid at 135m - not truly wide-angle but perfectly adequate for me.

PS. for what it's worth, exacting eye placement is by no means limited to modern binoculars, 8x42 or otherwise. In fact my experience is, if anything, the opposite - in general modern binoculars (very much including the 8x42 Noctivid, in the admittedly limited time I have had with it) are easier to use and have a more accessible view than many binoculars of the past. I agree the Swarovski 10x42 NL seemed to require more precision in terms of eye placement than the 8.5x42 EL I'm familiar with, but it's not quite apples to apples there.

 

[hopster]

Hopster,

You were using them since August and everything was fine until present. Any changes that you could recall, different viewing conditions from then to now, etc? I am only asking why all of a sudden, August is three months past.

I would say that everything except this has been fine, and I have been experimenting in the hope that I could find the magic combination of IPD and ER. Initially CA was also a bit more than I wanted but I discovered that careful eye position dealt with that.

 

[Conndomat]

Hopefully others who wear glasses will chime in.

Moin,

I don't find Noctivid with glasses that easy either!

I use it at the first click stop, here I can only put the glasses on very lightly and hold the binoculars as still as possible otherwise I'll get beans too.

The UV 7x42 is more comfortable here despite the shorter eye relief, the click-stop glasses wearer is a perfect fit.

My favorite with glasses is still the Swarovski 8.5x42, here the impression is excellent.

Just my 2 cents,

Andreas

 

[hopster]

I'm slightly hesitating to weigh in here, given the tone of your post #12, but here goes ...

No need to hesitate, I'm asking for informed input.

I really like the effect you get when you can move the field stop "far out" as I would call it - it gives you the oft mentioned "open window" and in general makes for a more pleasant viewing experience. But this is normally achieved by moving the binocular closer to your eyes and when you get too close, blackouts start to happen. Some binoculars allow me to move the field stop further out than others, but - certainly with the more modern ones with longer eye relief - there comes a stage that blackouts happen with all of them.

I get the feeling when reading your original post that your eyes are just a little too close, so that blackouts are only appearing at the edges of your field of view rather than across the whole image. My recommendation would be (not to teach you to suck eggs, but...) to extend the eyecups very slightly until the edge blackouts no longer happen. You will not lose actual field of view (this can be easily checked against landmarks) unless and until you move your eye back beyond the binocular's eye relief figure, which should not happen as we are talking very slight adjustments here and the Noctivid range have pretty generous eye relief.

Yes, I have explored the whole range from very close where the field stop is clearly visible and kidney beans are happening all the time, to a long way out where there is significant vignetting and I have lost the outer 10%. I did this in 0.5mm increments using O-rings. At no point in this range was the edge of the FOV easily accessible. So you'll see what I mean when I say I believe that I have covered all the ER possibilities.

In terms of modus operandi when observing - I am myself of the school that looks around my field of view to find things, rather than re-centering my field of view on everything I want to look at - I only do that when something of real interest is seen. I don't move my binocular relative to my eyes to get a clear view of the edges of the FOV - I aim to have set the eyecup distance up so that the entire FOV is accessible. FOV of my regular 8x42 (Zeiss FL) is I believe the same as your Noctivid at 135m - not truly wide-angle but perfectly adequate for me.

That's interesting. I'm still feeling out whether I can be satisfied with keeping my eyes in the centre and just noticing things in peripheral vision.

In my experience quite a bit of the edge in the FL is both out of focus compared to the centre due to the curved field and also slightly astigmatic. How much of it do you find useful?

PS. for what it's worth, exacting eye placement is by no means limited to modern binoculars, 8x42 or otherwise. In fact my experience is, if anything, the opposite - in general modern binoculars (very much including the 8x42 Noctivid, in the admittedly limited time I have had with it) are easier to use and have a more accessible view than many binoculars of the past. I agree the Swarovski 10x42 NL seemed to require more precision in terms of eye placement than the 8.5x42 EL I'm familiar with, but it's not quite apples to apples there.

OK, interesting. So you would consider the NV easier than average by the sound of it.