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ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia

Monarch HG 10x42 - How many ED elements? (1 Viewer)

John A Roberts

Well-known member
Australia
By way of context, binoculars are much simpler in terms of optical construction than many quality camera lenses
The difference is especially striking when one considers that a camera lens only performs a small portion of the optical functions of a binocular

See two optical diagrams from Swarovski:
• the first shows a telescopic sight (a form of terrestrial telescope), where a camera lens would only comprise the objective portion
(in a camera, the image is then projected on to the digital sensor or film emulsion while both inverted and reversed, and focusing is achieved by moving elements in the lens)

• the second shows a binocular, where the objective group in conjunction with the prisms brings the correctly orientated image to a focal point,
and the eyepiece group then magnifies the image
(the focuser is part of the objective group, the use of prisms enable a shorter length, and many binoculars have less than the 6 lenses shown in the eyepiece)


In contrast, compare the images of two Nikon 35mm format lenses:
- firstly, a relatively simple 50mm f/1.4 lens, with 8 elements in 7 groups, and
- a much more complex 24-70mm f/2.8 VR lens, with 20 elements in 16 groups; with 2 ED lenses indicated in yellow, 3 aspherical elements in blue and 1 aspheric ED element in orange!

- - - -

Binoculars are optically much simpler, both in terms of construction and glass composition, because the image quality required from them is much less
We use them to view in real time an object that is often in motion, often subject to atmospheric conditions, and often while we are holding the binocular without any additional support

In contrast, a static photographically recorded image is often scrutinised at length. And the image may be vastly enlarged to analyse the technical qualities of the image,
and the lens that took the image
So the image quality demands are often very much higher

- - - -

In terms of public awareness, Nikon started to use ED glass in some 35mm format telephoto camera lenses in the early 1970’s
However, the use in binoculars is a recent innovation. It was first officially used by Zeiss in 2004 with the introduction of the Victory FL line,
by Leica in 2007 with the introduction of the Ultravid HD line, by Swarovski in 2010 with the introduction with the EL SV line and also by Nikon in 2010 with the EDG introduction

Typically it’s used for 1 of the elements of the main objective group. However, some makers do use it for 2 elements e.g. in the Kowa Genesis XD models
(Often Nikon does not provide details about the optical construction of their binoculars, and I've not seen any detail about the current HG's)


As moyang_mm indicates, for descriptions of the effect of ED glass on chromatic aberration in particular models, see Roger Vine's set of reviews
at: http://www.scopeviews.co.uk/BinoReviews.htm
In each there is a section on CA, and the reviews include the Kowa 8x33 and 10.5x44, along with the Nikon HG 10x42
And for comparison, note the minimal CA in the Habicht 10x40 Porro that lacks any ED glass!


Finally, the degree to which the presence of CA is perceived as disturbing, varies greatly between individuals
If one's relatively insensitive then other considerations will matter much more when choosing a binocular


John
 

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Hermann

Well-known member
However, the use in binoculars is a recent innovation. It was first officially used by Zeiss in 2004 with the introduction of the Victory FL line, by Leica in 2007 with the introduction of the Ultravid HD line, by Swarovski in 2010 with the introduction with the EL SV line and also by Nikon in 2010 with the EDG introduction.

When Zeiss started making the 10x50 Porro way back in 1957, they said it had a "semi-apochromatic" objective lens:

"Bei unserem Feldstecher 10x50 ist als bemerkenswerte Neuheit das Objektiv zu nennen. Es ist ein sogenannter Halbapochromat, durch Verwendung moderner Glassorten wird bei ihm eine besonders gute Farbkorrektion erreicht." (Leinhos, Roland: Neue Feldstecher Modelle 8x50 und 10x50, in: Zeiss Werkszeitschrift Nr. 25, p. 79, 15.07.1957)

So the Zeiss 10x50 may well be the first binocular with what is today called "ED elements". Indeed, in use this binocular doesn't show any CA.

Hermann
 

Mark9473

Well-known member
Belgium
I guess only one element of the objective doublet is made of ED glass, and all other are made of regular glass?
In a doublet objective, the glass types have to be different, otherwise the combined objective will behave like a single lens and won't even be achromatic. So a doublet objective in which both elements are made from ED glass would be a very poor design.
 

John A Roberts

Well-known member
Australia
Hi Mark,

That’s true. However, the current high-end roof prism designs typically have 3 lenses up front in either a:
- 2+1 (Leica) or
- 1+2 (Swarovski, Zeiss, Nikon EDG) *
configuration

So it’s then possible to use 2 ED lenses e.g. see the attached image of the Kowa Genesis XD x33 with the 2+1 configuration


* The Zeiss SF x42 is an exception with only 2 lenses plus the focuser, to enable the ‘Ergobalance’ concept


John
 

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Mark9473

Well-known member
Belgium
John, yes, absolutely, that's why I was very careful in talking about doublets only, which is what the OP inquired about.

It is well known in telescope optics that a triplet with 2 ED elements is superior for photographic purposes requiring a very wide spectral range to come to common focus. For visual use a triplet with one ED element is plenty fine, or even an ED-containing doublet if the objective aperture ratio is slow enough (typically f/7 to f/7.5 in the smaller instruments).

Binoculars are a balancing act between being 'only' visual instruments of limited size used at low magnifications on the one hand, but having very fast aperture ratio's, often between f/3 and f/4, on the other hand.
 

Binastro

Well-known member
H. Dennis Taylor patented the Cooke photovisual telescope in 1892. It was an f/18 triplet apochromat using new Schott glass.
It was the best in the world.
However, after about 7 years it was realised that these new Schott glasses were unstable, and these telescopes had to be repolished every ten years or less in humid locations.
Firstly, the glass improved as it tarnished, but then hazed and eventually became unusable.

Semi apochromats had two elements sometimes.

High index glass improved over time, but is usually less hard and difficult compared to standard glass.
About 1939 Kodak introduced thorium glass, with the 7 inch f/2.5 Aero Ektar in volume production in 1940, followed by the 12 inch f/2.5, 8 inch f/1.5 and others.

50mm f/1.4 camera lenses were usually Gauss construction and 6 elements, but sometimes 7 elements. 8 elements was more exotic.

Good makers don't need to embelish their products with multiple claims of glass types and aspherics. This is just something used to draw in customers for lesser makes.

Aspherics are often molded plastic elements. In small sizes aspherics are relatively easy to make but large aspherics properly ground and polished are expensive and are avoided where possible. It is much easier to make a good spherical surface than a good aspheric surface.

The very best optics are still hand made and finished by master technicians. There are probably less than one hundred such individuals world wide.

B.

P.S.
I had a large Dallmeyer lens from about 1880 that was radioactive. It clearly contained some form of ED glass, possibly from sands from India.

Some Kodak WW2 eyepieces contain thorium and should be avoided.
 
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moyang_mm

Member
In a doublet objective, the glass types have to be different, otherwise the combined objective will behave like a single lens and won't even be achromatic. So a doublet objective in which both elements are made from ED glass would be a very poor design.

That makes sense. If the objective lens group is indeed a doublet, then we can be certain that Monarch HG only has one ED element.
 

John A Roberts

Well-known member
Australia
Hi moyang_mm,

I think the strongest indicators that the Nikon HG’s don’t have 2 ED lenses per side - regardless of the objective construction
- are firstly the price and secondly that Nikon does not state that they do have them

Looking at the BH Photo site, the HG 42's are at the edge of the critical US $1k threshold - $996.95 and $976.95
(the Kowa XD x42's are substantially more expensive $1.4k and $1.3k)

The use of 2 ED lenses per side is a rarity even in high-end binoculars. If used at the HG’s price level, it would certainly be stressed in advertising
It would be a decisive point in product differentiation, and also a decisive factor for many purchasers


John
 
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moyang_mm

Member
Hi moyang_mm,

I think the strongest indicators that the Nikon HG’s don’t have 2 ED lenses per side - regardless of the objective construction
- are firstly the price and secondly that Nikon does not state that they do have them

Looking at the BH Photo site, the HG 42's are at the edge of the critical US $1k threshold - $996.95 and $976.95
(the Kowa XD x42's are substantially more expensive $1.4k and $1.3k)

The use of 2 ED lenses per side is a rarity even in high-end binoculars. If used at the HG’s price level, it would certainly be stressed in advertising
It would be a decisive point in product differentiation, and also a decisive factor for many purchasers


John

Hi John,

The highest-end binoculars like Swarovski EL SV or Leica Noctivid don't specify how many elements are made of special glass either. It let me wonder if this means they only have single ED/UD/FL element as well. Zeiss Victory SF does mention that

"The UFL concept delivers them all. In the Ultra-FL Concept , several elements made of SCHOTT fluoride glass are combined in a system that delivers absolute
color fidelity, brightness, high contrast and the finest resolution of details."

https://www.zeiss.com/consumer-products/int/hunting/binoculars/victory-sf/victory-sf-8x42.html

Also I don't think the cost of special glass is that high. It has been commonplace in camera lenses for years, even in the cheap ones. I guess the role of low-dispersion glass is just less important in binoculars than in photographic lenses.

Thanks again for the informative reply.

moyang_mm
 
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NDhunter

Experienced observer
United States
My thoughts on the question, is that is does really matter how many ED elements the Monarch HG has
and also it is similar with other binoculars. I have owned the MHG for a couple of years along with the EDG
and find them very similar in view. A recent review posted calls the MHG the EDG lite, and I can agree
with that. The Monarch HG seems to be near the top of all mid-range choices, and well it should.
That's where I place it, I have tried most all of them.

I also own many other higher level models from Swaro. and Zeiss so they all have their merits.

So, in summation some binoculars without any ED elements perform very well, and there is no reason
to get hung up on how many ED elements are present.

I can see why the mfrs. do not specify, as some users may just be impressed by a buzzword. The key to any
good binocular is the optical design, the glass types and coatings. I suppose most should recognize that.

Jerry
 

moyang_mm

Member
I can see why the mfrs. do not specify, as some users may just be impressed by a buzzword. The key to any
good binocular is the optical design, the glass types and coatings. I suppose most should recognize that.

Jerry

Hi Jerry. I completely agree with you. The only thing that matters is the end result, not the types of material used. I am fairly new to binoculars, but one thing I've noticed is the lacking of a standard, objective measurement of optical qualities. Almost all camera lens mfrs provide a MTF charts with each lens. It is quite straightforward to compare the resolution of lens A vs lens B by just looking at MTF chart. I wonder why there is no such thing for binoculars/scopes.
 

Binastro

Well-known member
What is not mentioned here are the disadvantages of ED glass.

It is usually less stable than regular glass chemically.
It is less tolerant of thermal shock both in manufacture and use.
It is more likely to be attacked by fungus.
In negative curved elements the centre is very thin and can shatter.
It should be immediately coated when made and also be coated at cemented surfaces.
There is a higher failure rate.
It is more likely to absorb moisture.
It has a shorter lifetime than regular glass.

So more care and precautions need to be taken, and although the raw material may not be expensive, the final product may cost a lot more to make.

In the past there have been more problems with ED glasses over time than regular glass.

With good makers these problems are usually now well controlled, but lesser makers products still fail.

I have 1800s lenses which are in original condition quite unattacked by fungus after 140 years.
I have modern lenses completely destroyed by fungus.

I even had a brand new binocular with a lot of fungus inside.

B.
 

moyang_mm

Member
Hi moyang_mm,

I think the strongest indicators that the Nikon HG’s don’t have 2 ED lenses per side - regardless of the objective construction
- are firstly the price and secondly that Nikon does not state that they do have them

Looking at the BH Photo site, the HG 42's are at the edge of the critical US $1k threshold - $996.95 and $976.95
(the Kowa XD x42's are substantially more expensive $1.4k and $1.3k)

The use of 2 ED lenses per side is a rarity even in high-end binoculars. If used at the HG’s price level, it would certainly be stressed in advertising
It would be a decisive point in product differentiation, and also a decisive factor for many purchasers


John


Nikon mentions in the Chinese version of the sport optics brochure that Monarch 5, Monarch 7, and Monarch HG all have two ED elements per tube.

The brochure can be downloaded from Nikon:

https://www.nikon.com.cn/tmp/CN/4016499630/4196861409/2075060314.pdf

Not sure how reliable this information is though.
 

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John A Roberts

Well-known member
Australia
Hi moyang_mm,

The most recent English language version of the Sports Optics catalogue that I could find is one from 2019,
at: https://www.nikondownload.com/wpdm-package/2017-general-catalog-2/

I’ve included the table from it which lists the features of the full size models
(an earlier table that included the EDG line can be found at: https://www.birdforum.net/showthread.php?t=383112 )

The descriptions in the catalogue for the Monarch HG, 7 and 5 lines, state that they have ED glass - but they do not mention 2 elements per side


In addition:
a) The x42 Monarch 7’s are around US $500, and the x42 Monarch 5’s are around US $300, so the points that I made in post #10 would apply even more to them

b) In the reviews of various Monarch models - including HG's - by Roger Vine at ScopeViews and by Arek at Allbinos,
the comments about chromatic aberration make it clear that the performance is not what would be expected of binoculars with two ED elements per side


. . . so as to the reliability of the Chinese text?


John
 

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ZEISS. Discover the fascinating world of birds, and win a birding trip to Columbia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Colombia
ZEISS. Discover the fascinating world of birds, and win a birding trip to Colombia
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