Swarovski NL 8x42 - First Impressions (1 Viewer)

[AltaVista]

Do you imply that in case of moustache distorsion the user might be subjected to a ‘basketball’ effect, ie a rolling ball confined to a central zone?

Edmund

No, did not imply that and have not seen that but it is possible. The mustache distortion I have noticed in the past was visible in the outer 40% of the field whereas the central zone was calm.

I think these effects are well understood by most binocular optics designers now and are carefully considered so that we don't expect to see the disturbing mustache distortion effects that showed up in the past in some models.

Stephanie

 

[Troubador]

Thanks for your comment Henry. My professional field is optomechanical design and engineering. I have worked with optics for large aerospace companies as well as some small companies over the years. My expertise is in mechanical design of optical systems but I have worked closely with some of the best lens design engineers in the world and have learned much from them. One of the things that directed my career was my early interest in binoculars.

Stephanie

Excellent discussions Stephanie, thank you for your contributions.

Lee

 

[Hermann]

It's perhaps no coincidence that 35º (left and right) is the eye's maximum lateral rotation angle for 95% of the population.

That may well be the reason why Zeiss limited the field of view in the old wideangle porros (8x30, 10x50) to ~70º, although there were several eyepieces with wider fields of view (cf. König/Köhler ³1959, p. 160-173) and Zeiss had already made a binocular with a much wider field of view, the Deltar/Deltarem 8x40 (1937-1943, 198m/1000m).

It seems to me ~70º may well prove to be a very good choice when it comes to field of view.

Hermann

 

[Rotherbirder]

Excellent discussions Stephanie, thank you for your contributions.

Lee

I'll second that emotion (as the song goes)! Some very considered input from a knowledgeable & experienced contributor that even laymen can understand. Much appreciated Stephanie.

RB

 

[Holger Merlitz]

Regarding the expected distortion mapping in the new Swarovski NL models and to elaborate on Canips post just now and the link to Holger Merlitz's new graph showing the NL binoculars:

The published values for AFOV appear to be the actual design values since they are not the ISO (tangent mapping) and not the previously common estimations of AFOV = M x FOV (angle mapping) used in the past by many manufacturers.

These AFOV numbers would therefore not be estimates but actual values for the AFOV based on the design of the respective optical systems for the 8X42, 10X42 and 12X42 NL models. The optical design engineer would know exactly what these values are for the nominal design and may have had target values in mind in the design optimization process.

Holger Merlitz has published some informative technical work on the topic of distortion mapping in binoculars:
http://www.holgermerlitz.de/globe/distortion.html

In this work, Dr. Merlitz has proposed a “distortion parameter” K to characterize the distortion seen by the user of an individual binocular. In this work the K value can vary from 0 to 1.

K = 0 Imaging with the angle condition resulting in pincushion distortion
but uniform panning effects

K = 1 Imaging with the tangent condition resulting in rectilinear correction
(straight lines) but with rolling ball effect (or GE, globe effect) when
panning


Merlitz tested various observers with a simulated view of different K values and concluded that the optimal view with minimum perceived distortion and minimal rolling ball effects was achieved with a K value between 0.6 and 0.7.

Based on the published magnification, real FOV (m/1000m) and AFOV values the Merlitz distortion parameters for the Swarovski NL models is:

8 X 42 NL ------ K = 0.65
10 X 42 NL ------ K = 0.80
12 X 42 NL ------ K = 0.81

Based on these K values we might expect that the 8X42 will have close to optimal distortion with slight pincushion and minimal rolling ball effect. The 10X and 12X may well have less pincushion and some noticeable rolling ball based on these calculations.

However, the Merlitz K value is based on the assumption of a simple uniform proportion between object angle and image angle. If the binocular optical design has the so called “mustache distortion” (present in some previous Swarovski binoculars) where the distortion might vary from pincushion to barrel distortion as the field angle increases then the Merlitz K parameter does not strictly apply.

This observer is looking forward to evaluating the new NL binoculars, especially the 8X42 NL which might just have optimal distortion correction combined with high definition across the field of view.

Stephanie

Thank you so much, Stephanie, you have summarized these points better than I could possibly have done.

Although these numbers which are derived from the actual apparent angles of view are intriguing, we must be aware of their limitations. As you have already mentioned, we only obtain the total distortion, integrated over the entire angle, but not the actual distortion curve. The Zeiss 8x42 is an example where such a calculation fails, since it appears to have the right k-value but is nonetheless suffering a globe effect because its distortion curve drops toward the edges. On the other hand, the 10x42 SF is fine.

Another shortcoming arises from rounded numbers. A representative of Swarovski has mentioned to me that some of my computations are inaccurate because the magnifications of binoculars are not precisely as stated in the data sheets. Of course, it affects the relative distortion if e.g. a 8x42 is actually a 7.8x42. I asked Swarovski to pass me the exact numbers to get the numbers straight, but they refused to do so

Apart from these shortcomings, it is nice to know that more manufacturers are now offering actual AFOV specifications instead of those (rather useless) computed approximations.

Cheers,
Holger

 

[Troubador]

On top of all this, there is the question of the individual perception of the RB/GE which appears to very widely from one person to another. I have not seen RB in a bino yet although I did notice the effect when panning a defocused Meopta scope. Intriguingly during panning the same scope when it was focused I did not see the effect.

It seems to me to suggest that one should regard Holger's graph as one indicating probabilities rather than absolute certainties.

Lee

 

[Holger Merlitz]

On top of all this, there is the question of the individual perception of the RB/GE which appears to very widely from one person to another. I have not seen RB in a bino yet although I did notice the effect when panning a defocused Meopta scope. Intriguingly during panning the same scope when it was focused I did not see the effect.

It seems to me to suggest that one should regard Holger's graph as one indicating probabilities rather than absolute certainties.

Lee

Yes, perception differs quite a bit among individuals, there is no recipe which is ideal for everybody.

Cheers,
Holger

 

[Chosun Juan]

.... It seems to me to suggest that one should regard Holger's graph as one indicating probabilities rather than absolute certainties.

Lee

Yes, perception differs quite a bit among individuals, there is no recipe which is ideal for everybody.

Cheers,
Holger

Lee - do Holger's excellent eye distortion test - it proved a very accurate predictor for me.
The more data gathered, the more accurate the results :t:




Chosun :gh:

 

[jgraider]

My suggestion would be when you pick up any binocular, let your eyes and brain tell you how much you like or dislike that particular binocular, and not let any preconceived notions, opinions, or specs get in the way.

 

[Canip]

Excellent discussions Stephanie, thank you for your contributions.

Lee

I fully agree, Lee, thank you all, this is one of these great threads again for me and, I am sure, other people like me who are not experts but are interested to learn and try to understand more about this wonder device called binocular.

 

[pbjosh]

A question for Holger, Stephanie, and all other knowledgable optics folks here: Is there any method available to a typical user, or to any end user perhaps, including an optics specialist, to determine true magnification with any precision? The only way I'm aware of estimating it is simple division of measured objective lens diameter by measured exit pupil diameter.

Additionally, with field flattening yielding non-uniform distortion profiles (essentially I am trying to express anything other than a simpler design with naturally curved field), shouldn't magnification technically vary from one part of the field to another? Meaning that a "true magnification of the entire FOV" is something of an average?

As well let me chime in with Lee and Canip and others and express my appreciation of the in depth knowledge shared here. Tremendously cool place to learn!

 

[AltaVista]

A question for Holger, Stephanie, and all other knowledgable optics folks here: Is there any method available to a typical user, or to any end user perhaps, including an optics specialist, to determine true magnification with any precision? The only way I'm aware of estimating it is simple division of measured objective lens diameter by measured exit pupil diameter.

Additionally, with field flattening yielding non-uniform distortion profiles (essentially I am trying to express anything other than a simpler design with naturally curved field), shouldn't magnification technically vary from one part of the field to another? Meaning that a "true magnification of the entire FOV" is something of an average?

As well let me chime in with Lee and Canip and others and express my appreciation of the in depth knowledge shared here. Tremendously cool place to learn!

With true angle mapping in a binocular (with resulting pincushion) the angular magnification is constant across the field of view. With tangent mapping or some form of non-uniform image mapping the magnification does change across the field of view.

There are several laboratory methods to measure magnification with good precision.

As I think about a simple non-laboratory method the first thing that comes to mind is to use a digital camera to photograph a distant object like a chimney or utility pole and then using the same camera without changing the lens focus setting to photograph the same object through the binocular. Comparing the two resulting images using a photo editing application (like Photoshop) the number of pixels spanning the width of the chimney or pole can be determined for each image. The ratio of the number of pixels is effectively the magnification of the binocular. This depends on the small angle approximation to be accurate. You might want the object width to be no more than 10 degrees as viewed through the eyepiece of the binocular.

The camera lens used must be able to couple effectively with the exit pupil of the binocular eyepiece for this to work. Cell phone cameras tend to work well for this since the lenses are small and can get close to the binocular exit pupil. Binocular should be tripod mounted and camera should be rigidly attached to avoid image motion that will cause errors in measurement.

Hope all this is not too far off topic for this thread which is supposed to be about the new NL series!

Stephanie

 

[henry link]

I’ve been using the method Stephanie described for a long time without any complaints. I don’t have photoshop. I just place a transparent ruler on the computer screen to measure the size difference.

Henry

 

[SuperDuty]

Yes, perception differs quite a bit among individuals, there is no recipe which is ideal for everybody.

Cheers,
Holger

Hi Holger, how much does the night sky tell us about different distortions in binoculars that don’t necessarily show up clearly in daytime viewing, (pinpoint stars across the field of view), (spikes, or lack therefore on bright light sources), (CA around the edge of the moon), etc.
I’m interested in how the NL handles CA, The 10 x 50 SV I had displayed considerably more CA that I was comfortable with, my 10 x 42 SF is much better in that regard, for my eyes anyway.

 

[jremmons]

So to me, the biggest flaws with the EL SV/Field Pro are related to the control of stray light (especially with the 8x32 SV I previously owned, but also noticeable in the 8.5x42 FP I now use) and the slow close focus ratio. The FOV and ergonomic improvements are fine, but of minimal importance to me.
That said, can anyone speak on these two details?

 

[jan van daalen]

So to me, the biggest flaws with the EL SV/Field Pro are related to the control of stray light (especially with the 8x32 SV I previously owned, but also noticeable in the 8.5x42 FP I now use) and the slow close focus ratio. The FOV and ergonomic improvements are fine, but of minimal importance to me.
That said, can anyone speak on these two details?

I'll have the opportunity to check for stray light control in august 7 and 8 but from memory the focus is faster on the NL compared to the ELSV.

Jan

 

[RobMorane]

Today, I was lucky enough to try the new NL Pure in all the magnifications (8x 10x and 12x), Thanks to the Swarovski Caravan Tour making a stop in Thonon les Bains (French side of the Leman Lake).
They parked their van at an amazing point of view, with a mind blowing full view on the Leman Lake (and the sailing boats) and on the Swiss coast 10-12 Km away across the lake (pictures will follow).
After a week of bad weather, we could see Switzerland without any issue.

It was really a very nice place and conditions to try the new models like the DG (and some "old" ones, Habicht, SLC 42, CL ... )

So you'll find below my thoughts about the new*NL Pure. Please note that I'm not a professional reviewer in any way, but I tried my fair share of Binos through the years (Crappy ones, middle range and Alphad) so I do have some ideas of what's good and what's not.

HANDLING
Even if I still find them "ugly", to my surprise, I have to say that they are very confortable to hold.
I thought I would have an issue with them (mainly because I have quite big hands, and I never could handle the EL well for example).
Wrong I was.
The ergonomic handling reminds me a bit of the Kowa SV 10x50 somehow.
The Balance is great, and the Binos feels very light in my hands (I'm used to the SLC 56, so it's no surprise though).
I took a look at the inside through the objectives and it was very clean (I wasn't expecting less).

OPTICALLY
Brightness: They are very bright to me. Even the 12x42.

Contrast: Very Good, I would say a bit improved from the EL (I compared them). The image through them is somehow a bit more vivid too.

3D: 3D effect is there.

Colors: I found them neutral

CA: None to be seen.

Edge Sharpness: Well, I agree with Jan, I haven't seen any edges. Sharp to the edges, Period.
I wouldn't say the image is immersive as Swarovski states, but I was nicely surprised.

FOV: That's wide, that's all I can say. I always used Binos with minimum FOV (my first binos had a 88m FOV, the SLC 15x56 is even less: 78m) so I'm not an expert on that field.

Rolling Ball: None, and I'm quite sensitive to it.

MISCELLANEOUS
Diopter: Solid and very precise stuff, it won't move easily.

Forehead rest: I thought it wouldn't be useful. God I was wrong (again). It REALLY provides stability in a simple and confortable (and amazing way).

CONCLUSION: These NL Pure are GREAT, whatever the magnification.
I compared the picture with my 15x56 SLC (AK Prisms and higher transmission) and the only difference I found was the image was maybe a bit more vivid (more peps) in the NL (don't forget we are comparing 42mm and 56mm).
The ones who pre-ordered them won't be disappointed.

But I realize I haven't talked about my only possible negative point of the NL Pure I tried:
The Focuser!
They were Demo Binos, so I'm sure they might have endured more than usual, with a cable around the bridge and all, but I could feel a little lag in the rotation of the focuser at least 2 of the 3 Binos (like if the Focusser wasn't responding straight away to the rotation of the wheel). It annoyed me a bit.
Other reviewers who knows way better than me found it precise, so I'm sure they're right and it was just an issue with the demo Binos.
Will I buy them? No, they are out of my budget.
But I will probably buy SLC 42 at some point.

A quick note: The Swaro Representative was a very nice guy, and very informative.
I learned few things I didn't know about Swarovski, and I'm thankful to him for the time spent and the interesting exchange.

If you have any questions, go ahead.

 

[Canip]

Thank you for this personal and very nice review!!
Canip

 

[RobMorane]

Thank you for this personal and very nice review!!
Canip

Thanks to You Canip.
Actually, it's your own review, together with Jan and Gijs ones that pushed me to do the 2 hours trip to Thonon this morning.
I wanted to bring something useful to this forum (for once :-O)

 

[RobMorane]

And you will find in the PDF's attached the pictures of the Swaro Caravan and of the mind-blowing view.