Swarovski SL porro models (1 Viewer)

I ran across a photo of the sleek "SL" porro-prism bino from the 1980s, which I've never seen. I'm curious to hear what owners (present or past) think of them, compared to others (Zeiss etc) of the period. They appear to have internal focusing, perhaps the only porro models that did? How close did it go?

I have the 8x56 SL, they are a big binocular, large in size, and simple in their optics with their
porro design.
Gijs could comment on the history, and Henry has experience with several of the models when
they were current, there are threads on the model if you go back and look.

Jerry

OK, lazy me... quick summary of several threads that came up in search: optics similar to Habicht line (nice but limited FOV), often yellowing over time. Clunky forward focus knob moving oculars inside modernized shell, uncomfortable eyecups, eye relief not glasses-friendly. (Did I miss anything?) They do look nice though, better than other sleek porro designs like Docter Nobilems. I just never got a chance to see one.

Hello All,

I’m late to the party as I’ve been occupied with other things for most of the week. However, after getting my notes and thoughts sorted . . .

From Swarovski Optik’s start in 1949 until the SL’s introduction, all their binocular production was metal bodied, traditionally styled Porro prism models
The binoculars were and are still referred to, by what was then SO’s generally used brand name of Habicht, which is German for the Northern Goshawk


SL Choices and Specification
The SL Porro prism binoculars were made from 1980 to early 1998. They were offered in various configurations, which were in order of introduction: 7x42, 10x40, 7x50, 10x50 and 8x56
(see the table of basic data compiled from various Swarovski sources, along with 4 images of a 7x42 unit recently listed by 20abrakadabra12 on eBay)


On Introduction
At the time of its introduction, the SL was notable for several reasons:
- the distinctive lines and deep thumb grooves made it look like ‘something from the future’

- the lightly textured external finish added to the ultra-modern appearance

- it was both centre focus and air-tight, which was rare

- it made extensive use of synthetic materials for structural components, and

- it incorporated both a novel form of prism assembly and body construction


However despite the appearance:
- it was still an external focus design (as the eyepieces were focused they moved in and out of the rear body coverings)

- the optics were also conventional (they used the prisms, lenses and optical patterns of the existing Habicht line - though unusually with the prism pairs cemented together)

- consequently, the various models had the limited eye relief common to the Habicht series, and all but the 10x40 had a narrow field of view (see the table)

- the models also had the restricted minimum focus distances typical to binoculars of the era (again see the table), and

- the focuser which was located on the front of the axle, had a perceptible cogged feel to its operation


Historical Context
By 1980, both Leitz and Zeiss marketed roof prism binoculars (solely in the case of Leitz, while Zeiss continued to offer Porros but only in x50 and x60 sizes)


In 1980 the state of play was:
- Leitz offered the v2 Trinovid series. Introduced in 1963, it was progressively offered in 6x24, 8x32, 10x40, 7x35 B, 7x42 B, 8x40 B, 8x32 B and 10x40 B
(with the last introduced in 1974, and with rubber armoured versions starting from 1979)

- Zeiss offered the Dialyt 8x30 B and 10x40 B models, introduced in 1964 and 1968 respectively (and available in leatherette or RA),
along with the old Hensoldt style 7x42 B and 8x56 B models, and

- Zeiss had introduced multi-coating in 1978, which had been quickly adopted by many other manufacturers including Swarovski


And following on from then:
- in 1985 Swarovski introduced it’s first roof prism model the 8x30 SLC

- in 1988 Zeiss introduced phase coating, which eliminated the slight image softness inherent in roof prism optics (and the coating was also quickly adopted by other manufacturers)

- in 1990 Leica introduced the Ultra/ Trinovid BA series (which many would consider the first modern full sized roof prism binocular)

- in 1992 Swarosvki introduced the x42 SLC models (with the x50’s not until 1997, and the x56’s in 1998 and 1999)

- in 1994 Zeiss introduced the Design Selection/ Night Owl series

- in 1998 Zeiss introduced dielectric prism coating, for the non-Total Internal Reflection surface found on most roof prism pairs
(and again the coating was quickly adopted by other manufacturers, and is known as Swarobright when used by Swarovski)

And then in 1999, Swarovski introduced the unique open bridge design EL series


For images of some of the above models see here, especially posts #5 and #13: https://www.birdforum.net/showthread.php?t=377255

The Details

External Design
- Shape and Size
The external design was that of Werner Holbl (see the attached drawing from the site: www.clponline.it )
And since then, Holbl has been responsible for the external design of most of Swarovski Optik’s products
(see the image of various binoculars from his book of designs, at: https://www.koop-andreas.de/buecher/detail?id=97 )

With its clean flowing lines, including the large thumb grooves on the rear of the body, the SL’s design was intentionally modernist
When introduced it was strikingly different to any other binocular, and even now it’s distinct from any other Porro model

However, the curved and rounded shape resulted in a much more bulky binocular than its Habicht predecessor
Although I haven’t been able to find any side-by-side photos of the SL and the Habicht:
- an image from Gijs van Ginkel gives an idea of the respective sizes (it’s from Gijs’ presentation on Swarovski Optik at: https://www.houseofoutdoor.com/verrekijkers/verrekijkers-testen-en-vergelijken/ )

- and while the image of the rear of the SL shown in my first post, gives some idea of the depth of the thumb grooves,
a side view of a 7x50 unit makes this much clearer (it’s from a 2014 listing by kilowattcat on eBay)

While preferences vary in terms of ergonomics, the SL’s much greater bulk compared to conventional Porros, didn’t make it a good choice for those with smaller hands
(and adding to the problem, the SL was also a heavy binocular - see the table in my previous post)

With the advantage of hindsight, a critical assessment would be that: the aesthetic purity of the design, was a step too far in terms of functionality
However at the time, the striking nature of the design created considerable interest in both the SL and Swarovski Optik


- Texturing
In keeping with a modernist aesthetic, the SL had a minimally textured surface
This was in distinct contrast to the prominently ribbed but otherwise smooth ‘military style’ rubber armouring then used on binoculars
The minimally textured finish introduced on the SL went on to become the standard for later Swarovski products

SL Designation
As I’ve noted elsewhere, the SL designation seems to stand for ‘Stossfest en Lange Lebensdauer’, which translates into English along the lines of ‘shockproof and long life’
(for the original reference see here: https://www.birdforum.net/showpost.php?p=3842195&postcount=3 )
And clearly this was Swarovski’s primary intention with the SL


Synthetic Materials
- In General
As with many other products, manufacturers have used ‘plastics’ for binoculars with varying degrees of success
While binoculars commonly use RA coverings over metal bodies, it’s far more unusual for higher quality products to use synthetic materials for structural components

The longest continuous use of plastic structural components is by Steiner, which dates backs to the mid-1960’s. On their individual focus Porro prism binoculars,
poly-carbonate is used for the body shell (for a cutaway image and some additional detail see here: https://www.birdforum.net/showpost.php?p=3888243&postcount=21 )

And of historical interest, much earlier on during WWII, the German firm of Emil Busch used a bakelite shell for the for some of its standard pattern 6x30 service binoculars
(see the image from: http://gerhard03.blog61.fc2.com/blog-entry-240.html )


- In the SL
The SL design was much more ambitious than that of Steiner, since it both:
- incorporated the added complexity of an air-tight centre focus mechanism, which was necessarily subject to continuous operation (unlike the typical ‘set-and-forget’ focusing of IF binoculars) and,

- made much more extensive use of synthetic materials

In relation to the second point, the design goal seemed to have been to only use metallic components where absolutely unavoidable


SL Body
The most notable technical aspect of the SL was that each half of the body was in effect constructed from the inside out (as opposed to having components inserted into an existing shell):
- the prisms were cemented together, and then had a tube cemented at each end

- the prism assembly was then placed in a fixture, and

- liquid polyurethane (PU) was poured into the fixture and allowed to set

The PU formed a solid casing with the prism components permanently bonded to it


The construction can be seen in the attached cut away view of a 7x50 model (per Henry Link at: https://www.birdforum.net/showpost.php?p=2692087&postcount=67 )

In the 1991 paper ‘Progress in Binocular Design’, Konrad Seil who was an engineer at Swarovski, discusses the prism assembly
(the paper can found at: https://wp.optics.arizona.edu/optomech/wp-content/uploads/sites/53/2016/10/Seil-1991.pdf )
See both:
- an excerpt from the paper, describing the process in greater detail along with it’s advantages, and

- a photograph showing in succession, the seperate prisms, the prisms glued together, and the prisms with the ocular and objective tubes attached

And the construction is described in even greater detail in the attached copy of the US patent filed in 1976


Two consequences of the solid PU casing were:
- there was no need for a seperate RA covering, but

- the casing made the SL’s relatively heavy


- - - -
Relationship of PU Casing to External Design?
The use of a solid PU casing may have provided the initial impetus for Holbl’s radical design for the SL

As a conceptual process he could have commenced with a solid block and then removed excess material to produce a desired form
(while being mindful that he couldn’t go below certain minimum dimensions and into the mechanism)
So like a sculptor revealing the ideal form visualised inside the medium?

Metallic Components
While synthetic materials were used for the great majority of the SL components, there was also the use of:
- pins and screws (see the images)

- along with metal rings to centre and retain the objective and eyepiece lenses

- together with glue to provide additional bonding (again see the images)


Focuser Action
In operation, the focuser had a distinctive geared feel, rather than a smooth action. This was due to the use of a large toothed plastic cog in the mechanism (again in the images below)


More Images of Construction
Further details of the construction can be seen in the following images:
1) shows a unit missing the rear body coverings

2) shows the use of screws to hold various components in place under the rear coverings

3) shows the rear of a binocular with the eyepiece missing. It makes clear: the attachment of the neck strap lug by a screw; the use of glue to help secure the eyepiece assembly,
and; the geared wheel used to focus the eyepieces

4) shows the underside of an eyepiece. Both a positioning lug that fits into the binocular body, along with the recess for the geared focus wheel can be seen, and

5) shows an ‘impromptu cutaway’ where the prism assembly is still attached to the intact parts of the casing! (it’s an ex-MN unit - see ‘IF Versions’ below)


Sources:
- the first 2 are from a 2015 listing by binocularaddict2-2009 on eBay
- the next 2 are from a 2015 listing by ricki81 on eBay
- the last is from a 2018 listing by sitmerel on eBay

Optical Design
As the SL series optics were those of the Habicht line, the optical performance was the same. The 2 less air-to-glass surfaces due to the cemented prisms while technically interesting,
would have had only a very minor effect on the transmission of the multi-coated optics (a 2% increase in transmission at the very most)


Multi-Coating
- General
The conventional view is that multi-coating (i.e. initially 3 layer broad band coating) was introduced by Zeiss in 1978 under the T* designation
And this is probably true in the sense that, from then on it was increasingly used on binoculars, and consequently it became a significant point in product promotion and differentiation

However as I’ve previously noted, the commercial use of multi-coating by Swarovski dates back to 1965
- when it was known as Iralin and used on draw tube telescopes (click on the first link contained within the link below)
And it would be greatly surprising if there was no other commercial use of multi-coating substantially prior to that of Zeiss in 1978


- On the SL
The SL’s were multi-coated from their introduction in 1980 (and from that time onward Swarovski’s multi-coating is known as Swarotop)
However, on the basis of the extensive work done by Gijs van Ginkel, we know that at least in it’s initial implementation,
Swarotop had significantly lower transmission than the refined form of Swarovski’s standard dual-layer DV coating!

For a starting point see here: https://www.birdforum.net/showpost.php?p=3890121&postcount=10
It contains my most recent thoughts on the subject, and it in turn links to Gijs’ transmission graphs in relation to the improved performance over time of Swarotop on the SL models

Paralleling the progress in the transmission levels of Swarotop, the degree of yellowness of the image also progressively decreased
(this was not only the case with the SL line but also all the other Swarovski product lines)

For those technically inclined, I’ve also attached a copy of Swarovski’s 1981 US patent application for multi-coating


‘B’ designation Models
All of the SL production had short eye relief, and most had hard plastic eyecups. However, when the 8x50 was introduced in 1984 it was given a B designation
While the designation typically indicates long eye relief suitable for spectacle wearers, in this instance it only indicated that the the 8x50 had foldable rubber eyecups
Similarly, when the 7x50’s eyecups were upgraded in 1992 it was also given a B designation, but the eye relief did not change


Colours
The PU body of the SL’s came in 2 main colours, either black or green. In addition, some 7x50’s were made in a bright ‘safety’ yellow, or a dark blue and marketed as Marine models
However, while the colours differed there were no other modifications for use on or around water
The image from Gijs in a previous post shows the colour options

IF Versions - for the French Navy
There is an exception to the commercial centre focus production. Between 1987 and 1993 the French Navy (the Marine Nationale) purchased a total of 3,000 units
These were a mix of 7x50 and 10x50 models, and were fitted with individual focus eyepieces

(The details are from Johann Leichtfreid’s under appreciated site fernglasmuseum, which also includes numerous photos of:
- a 7x50 MN unit: http://www.fernglasmuseum.at/museum/swarovski_mn_7mal50/swarovski_mn_7mal50.html , and
- a 10x50 MN unit: http://www.fernglasmuseum.at/museum/swarovski_mn_10mal50/swarovski_mn_10mal50.htm )


As can be seen from the instruction manual, the factory designation was ‘Habicht SL 10x50 O L STP’, where:
- O indicated individual focus (okular-einzeleinstellung i.e. ’individual setting’; verses M for centre focus - mitteltrieb i.e. ’central drive’)

- L indicated laser filters were fitted (laserschutz i.e. ’laser protection’), and

- STP indicated the presence of a reticle (strichplatte i.e. ’line plate’)

From my observation it appears that the initial 7x50 production was in the previously mentioned marine blue, while all later 7x50 and 10x50 production was black

And as can be seen from the first photograph the MN model came with a heavy duty leather case


n.b. Swarovski has a generous repair policy that applies to commercial production
However the policy does not include contract production, since contracts typically specify warranty and servicing provisions and limitations
So Swarovski would now be likely to charge for the servicing of any IF unit (used MN units in various states, are advertised with some frequency on various French sites)


Photo sources:
- the first 2 are from a listing on the French site naturabuy.fr by kadoray
- the next from another French site delcampe.net by depot_des_equipages - which shows the presumedly original gold marking on the MN logo
- and the reticle image is from Leichtfreid’s site

Summary
The SL series can be considered in at least two ways:
- Whether it was a success as a product
- What it did for the Swarovski Optik brand


As a Product
As can be seen, the SL’s were a mix of the then:
- unique (external shape and texture, materials and construction)

- novel (combining centre focus with air-tightness, focuser feel, cemented prism pairs)

- conventional (external focus, minimum focusing distance), and

- dated (most of the optical specifications)


As to how well the mix of features succeeded?
When reduced to the essentials, what would have mattered to most purchasers would have been the combination of handling and manipulation, together with optical qualities
And in relation to these criteria the SL suffered from being bulky and heavy, with an unusual focuser action, and with both limited eye relief and field of view (excepting the 10x40)

But the SL’s main problem was that it was a Porro prism binocular in an increasingly roof prism world (see ‘Historical Context’ in my first post)
And as such it was in a near impossible position. Even if it had performed as well as the roof prism alternatives, most purchasers would have chosen a RP model


- compared to the traditional Habicht
Again in terms of the essentials, the SL offered Habicht optics, plus multi-coating and an air-tight housing, but with an unusual focuser action

However, over time Swarovski eliminated the distinctions:
- in 1984 it updated the Habicht so that it also had air-tight construction (identifiable by the valve cap screws on the bridge arms) along with a smooth but heavy focuser action, and

- in 1992 the Habicht was also given the then latest version of Swarotop multi-coating

And now 20 years after the SL’s demise in 1998, the Habicht is still in production - though essentially as a low volume legacy product

However, we also need to consider the SL’s . . .


Effect on the Swarovsk Optik Brand
In 1980 Swarovski Optik didn’t have the status that it now shares with Zeiss and Leica. Many outside of Austria and Germany, if they new anything at all about the company,
would have considered that it was just one among a number of German (sic) second tier manufacturers of old style binoculars

Traditionally, one way to raise a company’s profile is to market a so-called halo product i.e. a product designed to showcase superior technology or other capabilities
The aim is that the positive associations with the particular product will extend to the other products with the same brand, and thus elevate the brand’s status as a whole
(e.g. see see the Wikipedia article: https://en.wikipedia.org/wiki/Halo_effect )

Since it was such an aesthetic and technical tour de force, the SL did do much to raise Swarovski Optik’s profile with the binocular buying public
So it could be narrowly considered as a successful attempt at a halo product

However much more significantly, the SL also signalled the start of a period of ongoing innovation by Swarovski Optik that continues to this today
I’ve attached a 2 page table that shows the main introductions to the various Swarovski commercial product lines
The first page shows the first 50 years to 1998, and the next from 1999 on - marked by the introduction of the EL binocular

It’s clear that while the SL may not have been the success hoped for, it was not an isolated act - but rather the first step on the road towards the company’s current status


John

Thank you so much!

John A Roberts said:

Summary
The SL series can be considered in at least two ways:
- Whether it was a success as a product
- What it did for the Swarovski Optik brand


……….
And now 20 years after the SL’s demise in 1998, the Habicht is still in production - though essentially as a low volume legacy product

However, we also need to consider the SL’s . . .


Effect on the Swarovsk Optik Brand
In 1980 Swarovski Optik didn’t have the status that it now shares with Zeiss and Leica. Many outside of Austria and Germany, if they new anything at all about the company,
would have considered that it was just one among a number of German (sic) second tier manufacturers of old style binoculars

Traditionally, one way to raise a company’s profile is to market a so-called halo product i.e. a product designed to showcase superior technology or other capabilities
The aim is that the positive associations with the particular product will extend to the other products with the same brand, and thus elevate the brand’s status as a whole
(e.g. see see the Wikipedia article: https://en.wikipedia.org/wiki/Halo_effect )

Since it was such an aesthetic and technical tour de force, the SL did do much to raise Swarovski Optik’s profile with the binocular buying public
So it could be narrowly considered as a successful attempt at a halo product

However much more significantly, the SL also signalled the start of a period of ongoing innovation by Swarovski Optik that continues to this today
I’ve attached a 2 page table that shows the main introductions to the various Swarovski commercial product lines
The first page shows the first 50 years to 1998, and the next from 1999 on - marked by the introduction of the EL binocular

It’s clear that while the SL may not have been the success hoped for, it was not an isolated act - but rather the first step on the road towards the company’s current status


John

Click to expand...

John, this is a very fine set of posts! Thank you so much for giving us all this fine summary of the insights you have gained over the years. My thanks include your posts on other brands such as Zeiss.

Yes, thanks for all that information. That diopter scale inside the right eyecup looks useless because there doesn't seem to be an index mark for it. And here we have the original thumb grooves! (For very large thumbs.)

Interesting that this distinctive SL line was then discontinued in favor of the traditional Habichts. I suppose those who prefer the modern look also prefer the modern roof-prism bino.

John:
Thanks for the well done presentation, it is a very complete history the Swarovski SL.

I have a few observations, one is that before Swarovski was ready to enter the roof prism market,
they were able to work on a design to bring forth a sleek designed porro prism, with the poly body,
without the dog-leg design of most all porro-prism models.
This helped smooth the transition they were working on at the time, before they had the roofs ready.

The SL was a further developed binocular for Swarovski, as it was made in larger objective models, as
in the 10x50 and 8x56 sizes. This size was important as Zeiss had the 8x56 Dialyt, a very popular model
for hunters, so they had an option here.

The current Habicht porro models have not changed from the current sizes, 8x30, 7x42 and 10x40.
It is very good that those quality options still remain, and with updated coatings they are still up at the top
of optical qualities.

Jerry

Diopter Index Mark

Hi tenex (post #12),

Although it’s very hard to see in most photographs, there is an index triangle on the back of the right hand housing for the diopter scale
I had to hunt around for some time to find a useable image, and then do a bit of exposure and contrast alteration
The image is from a 2015 eBay listing by rmaness1977


John

John Roberts, post 4,
The term Habicht for Swarovski binoculars can stand for a hawk, but I was assured by older Swarovski employees that it originally was referring to the Habicht mountain in the neighbourhood of the company. I actually started a contest for the BHS members when I gave the original presentation in whiche we asked them to guess what the title Habicht stood for. The winner would receive a brand new Habicht binocular. Nobody guessed it right, but nevertheless the binocular was sold to the highest bidder, the money went to the BHS organisation.
Gijs van Ginkel

tenex said:

OK, lazy me... quick summary of several threads that came up in search: optics similar to Habicht line (nice but limited FOV), often yellowing over time. Clunky forward focus knob moving oculars inside modernized shell, uncomfortable eyecups, eye relief not glasses-friendly. (Did I miss anything?) They do look nice though, better than other sleek porro designs like Docter Nobilems. I just never got a chance to see one.

Click to expand...

Hello Tenex,

I had the 7x50 for a while. I found that the optics were no better than a Leitz Marseptit from 1948, with a somewhat narrower FOV. Mine suffered from internal fogging.

Happy bird watching,
Arthur Pinewood :hi:

John A Roberts said:

Although it’s very hard to see in most photographs, there is an index triangle on the back of the right hand housing for the diopter scale

Click to expand...

Yes, I see that now, quite normal. Previously I was looking at the top view in your post #4 which shows curious diopter markings inside the eyecup, where no index mark is possible.

Anyway, an interesting episode in the development of modern Swaro binos.

Hi Gijs (post #15),

Mea Culpa! - you are of course correct. My sin was was the error of brevity

The meaning of Habicht as originally used by Swarovski Optik, comprised both the Northern Goshawk and the Habicht mountain (30 km or so from Absam as the hawk flies)
And obviously both meanings provide positive associations for optical products

In 2015 Swarovski posted about the history of their usage at: https://www.swarovskioptik.com/chasse/blog/SWAROVSKI_OPTIK_and_the_Northern_Goshawk_hunting


In advertising from 1952 onward, there was often an image of both:
- the mountain in the background, and
- the hawk perched on a binocular in the foreground
This dual image was used until at least the early 1960’s, but not much later (see a 1952 version from Gij’s presentation on Swarovski Optik) *

For a period from then, it seems that the advertising and literature just used images of the then current word logo (variations of Swarovski Optik and Habicht)

By 1980 the current image of the hawk about to strike was introduced (and there was no longer any reference to the mountain)
e.g. it was in use on early SL packaging: see the image of an SL box for unit #57,274; numbering had started in 1980 at #50,000
(the image is from a 2015 listing by sell-it-now44 on eBay)

The introduction of the current image seems to coincide with Swarovski’s revitalisation as a company, see my latter comments in post #10


In closing, there does not seem to have been any obvious use of the Habicht-Mountain association since the mid-1960's - so an understandable venial sin on my part?


John


* the Swarovski link includes an image that I'd not seen before - the hawk in full flight - and by it's appearance it may predate the more usual image from 1952
(the binocular appears to have the recessed markings of pre-1952 production, which were marked HABICHT rather than Habicht;
compare it to a pre-1952 unit from a 2014 listing by foto-hobby24.eu on eBay)

John Roberts post 18,
You are forgiven, nobody really knew about the Habicht mountain also not in the ranks of the BHS , I did not either and learned about it when preparing my presentation.
Gijs van Ginkel

I remember the Swarovski SL porro models. And I remember the pitch dark area surrounding the exit pupil, indicating a minimal of inner reflections. The new modern roof series have a lot of light around the exit pupil from the inside and prisms. Is that mainly a roof issue? It seems that the evolution has gone in the wrong direction here.