Swarobright V.S. Non-swarobright optics (1 Viewer)

Recently I have purchased a pair of 8x30SLC with new swarobright optics. I have noticed that SLCs produced in different years come with different coatings. I wonder if there is much difference in color tone between new swarobright optic and Leica's offering.

I looked carefully through several SLC and Leica models recently. I'm not sure that one could identify a Swaro or Leica product based on color tone alone. Having said that I always find Swaro views more restful for some reason, and Leica more harsh. That, could be a lot of factors rolled together. No doubt Leica fans see it differently. :eek!:

The current SLCs all have a very neutral image. However, let me comment on something elkcub just said. I have used a 1999 model 7x30 SLC, and I borrowed it for two long days at a raptor migration site. The subtle amber color cast would be rejected by many as being sub-standard, but in that intense light at over 7,000 feet elevation, the image was very soothing and easy on the eyes. I came to like it quite a bit. And by the way, the 7x30 SLC is one of the truly great, underappreciated binoculars of all time. Despite its relatively narrow field of view (378 feet @ 1,000 yards) it has an amazingly natural image. It is not razor sharp like the SE or Ultravid, but the image is really quite superb.

Jonathan,

Thanks for your appraisal of the the 7x30 SLC. By "natural image" do you mean color, or something else?

-elk

Swarovski and Leica attack problems from different ways. Swarovski uses the Swaro-bright lense coatings to achieve a clear bright image. I find the Swaros to give very comfortable viewing for hours at a time. Leica uses a higher grade of ED glass and quality coatings to achieve their view. Both are very good and it depends on who you ask as far as which image is superior. I prefer the Swaro's image, but the Leic is a much tougher and durable bino.

ranburr

ranburr

leicaeddy said:

Recently I have purchased a pair of 8x30SLC with new swarobright optics. I have noticed that SLCs produced in different years come with different coatings. I wonder if there is much difference in color tone between new swarobright optic and Leica's offering.

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Correct me if I'm mistaken, but I have understood that the
1) Swarobright is the interference/dielectric mirror of the reflecting roof prism surfaces which should just increase the reflection regardless of wavelength -> brighter image in general. Leica's solution is called Hilux.
2) Swarotop is the lens multicoating, which may be formulated to improve the transmission of some wavelengths more than the others. This may have changed during the years without specific comments.
3) Swarodur is the "hard" outermost layer of the exterior lens surfaces, which improves the scratch resistance of the multicoating. Introduced relatively recently.

To my eyes the SLCs have had a yellow/amber cast, which IMO is caused by the lens coating. The Swarobright models should be brighter, but do not necessarily have different colour. I have never myself owned any Leica optics, but from my experience their colours look more natural.

Jonathan - that was a good point that some colour casts may actually be good on the eyes in some conditions. I have just thought that the yellow is the colour that the German hunters originally wanted - to add some contrast in the morning mist

Ilkka

Determining Colour Cast

iporali said:

To my eyes the SLCs have had a yellow/amber cast, which IMO is caused by the lens coating. The Swarobright models should be brighter, but do not necessarily have different colour. I have never myself owned any Leica optics, but from my experience their colours look more natural.
Ilkka

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I have 'discovered' a simple way to compare the colour cast in binoculars. It is done by reversing the bino and looking through them the wrong way round! Place a white card where it will be strongly illuminated (indirect sunlight is best) and hold the eyepieces 30cm away and the object lens a similar distance from the eye.

Direct comparisons of the card with the view through side-by-side binos shows the cast distinctly. For me, I found the 8.5x EL has a very slight yellow-green colouration and the 8x32 HG/LX is slightly reddish. The Ultravid was just about neutral. On a former pair of 7x42 SLCs (pre Swarobright) the yellow-green cast was stronger but this may be because the image is less bright.

Chris

leicaeddy said:

Recently I have purchased a pair of 8x30SLC with new swarobright optics. I have noticed that SLCs produced in different years come with different coatings. I wonder if there is much difference in color tone between new swarobright optic and Leica's offering.

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Hi,

additional to what Ilkka said just some informations about differences in visual perception of SLC binoculars with Swarobright and without. The difference is quite visible. SLCs with Swarobright prismcoatings offer an image that is sharper with higher contrast especially in the center of the image. Recent SLCs have a more neutral image than older models. But as Ilkka said, the reason for that aren´t the prismcoatings but a change in lens coatings that Swarovski hadn´t advertised once. Even today I can see some old SLCs in optic shops where the dealer don´t tell you that they are old. So if someone want to buy a SLC make sure that it has Swarobright coatings. There should be an imprint on the binocular package indicating "Swarobright".

Steve

zurtfox said:

I have 'discovered' a simple way to compare the colour cast in binoculars. It is done by reversing the bino and looking through them the wrong way round! Place a white card where it will be strongly illuminated (indirect sunlight is best) and hold the eyepieces 30cm away and the object lens a similar distance from the eye.

Chris

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Chris,
That is a very good tip, which also shows if the bins have good or poor light transmission. It is even more accurate if you place the bins on an evenly illuminated light box (eyepieces down). Using this trick I first saw that my Nikon HGs have different color cast in each tubes, but then I found out that it was actually the difference of my eyes!

Steve - thanks for a useful piece of info.

Ilkka

elkcub said:

By "natural image" do you mean color, or something else?-elk

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I mean the way the image appears to the eye, which is impossible to quantify. I have noticed that some binoculars provide an image that is simply more lifelike. I was able to compare the 7x30 to an 8x30 SLC side by side, and the 7x30, despite its narrower field of view, gave the impression of simply being seven times closer to the subject. Stepen Ingraham mentioned this in some of his reviews in Better View Desired, and the 7x30 SLC is a good example of what he was trying to describe.

From what I have read in the SLC poster:"swarovbright is a coating technology that can selectively control the reflected light in the prism system. As a result, the color behaviour. For you this means: Binocular with the best color fidelity and the highest light transmission. Silvered mirror=usual loss of quality in the blue spectrum results in yellowish images.

Regarding the (SLCs' objective) lens coating, AFAIK, there are at least 3 different colors: dark blue, deep red and bright green. The green one is the latest model.

IMO, SLC with swarobright is good for binoc user but not for collector,'cause it kicks away the characteristic yellow/amber color tone.

iporali said:

Jonathan - that was a good point that some colour casts may actually be good on the eyes in some conditions. I have just thought that the yellow is the colour that the German hunters originally wanted - to add some contrast in the morning mist

Ilkka

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Color casts may be advantageous under certain circumstances. However, if I were allowed to own only one premium binocular , I would cling to the one that is absolutely color neutral. I bet most of forum viewers will share the same view. To boost up contrast, I prefer using additional color filter. B

leicaeddy said:

From what I have read in the SLC poster:"swarovbright is a coating technology that can selectively control the reflected light in the prism system. As a result, the color behaviour. For you this means: Binocular with the best color fidelity and the highest light transmission. Silvered mirror=usual loss of quality in the blue spectrum results in yellowish images.

IMO, SLC with swarobright is good for binoc user but not for collector,'cause it kicks away the characteristic yellow/amber color tone.

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As said above by Ilkka and others the purpose of Swarobright is to increase the amount of light reflected by the mirror surfaces. In a Schmidt Pechan roof prism binocular such as the 8x30 SLC the light in each optical assembly undergoes 5 mirror reflections, and thus the quality of the mirror surfaces is critical. In the past manufacturers used silver, but Swarovski, Leica, Opticron and others are now using expensive multilayer dielectric coatings. However Nikon use silver in the HG range, and their optics have superb brightness and contrast, so clearly silver can deliver the goods. I can only assume that it is some form of 'enhanced silver' whatever that might be. Many Zeiss roof prism binoculars use Abbe Koenig prisms which do not require mirror coatings as the uncoated glass mirror surfaces naturally reflect 100% of the incident light.

Incidentally, in my experience the main advantage of mirror coatings with improved reflectivity seems to be higher contrast and this is easily seen when comparing competing products side by side. It is interesting to compare the subjective contrast with the % transmissions for various binoculars given by someone in an earlier thread. There is also a review somewhere that compares a Zeiss Victory 10x40 with a Leica Trinovid 10x42 BA. The Zeiss uses AK prisms with no need for mirror coatings. The Leica uses IIRC traditional silver coatings. According to the reviewer, in terms of contrast the Zeiss knocks spots off the Leica. I have also compared the Nikon 8x32 HG and Leica 8x32 BN, and the higher contrast of the former is very obvious.

In the past many manufacturers targeted the hunting market and purposefully introduced a yellow colour cast to improve performance at dawn and dusk. There's other threads on BF addressing that issue. These days us birders seem to be the preferred prey species for optics companies and hence a natural image in daylight is the order of the day. My Swarovski 8.5x42 EL has a very slight yellow cast though I do not notice it unless I compare it side by side with my Nikon 8x32 SE. Or perhaps the SE has a slight blue cast?

Leif said:

..... In a Schmidt Pechan roof prism binocular such as the 8x30 SLC the light in each optical assembly undergoes 5 mirror reflections, and thus the quality of the mirror surfaces is critical. In the past manufacturers used silver, but Swarovski, Leica, Opticron and others are now using expensive multilayer dielectric coatings. However Nikon use silver in the HG range, and their optics have superb brightness and contrast, so clearly silver can deliver the goods. I can only assume that it is some form of 'enhanced silver' whatever that might be......

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Leif,

Although I am not certain I believe only 2 of the 5 reflections in a Schmidt Pechan prism have angles of reflection that require mirror coating. I recently noticed the following quote in some old Leica material on the subject of silver coating which might be relevant to your speculation above:

"The mirrored surfaces of the prism are vapor-deposited with a layer of pure silver. Processes using chemical silver or aluminum, for instance, result in a considerable loss of light."

This suggests that not all silver coatings are equally effective. I'm surprised, however, that Nikon didn't go to a dielectric coating with their new light weight HG's. I suspect their roof prism bins are as bright as they are owing mostly to very high transmission lens coatings and would be even brighter with dielectric mirror coating.

Henry

henry link said:

Leif,

Although I am not certain I believe only 2 of the 5 reflections in a Schmidt Pechan prism have angles of reflection that require mirror coating. I recently noticed the following quote in some old Leica material on the subject of silver coating which might be relevant to your speculation above:

"The mirrored surfaces of the prism are vapor-deposited with a layer of pure silver. Processes using chemical silver or aluminum, for instance, result in a considerable loss of light."

This suggests that not all silver coatings are equally effective. I'm surprised, however, that Nikon didn't go to a dielectric coating with their new light weight HG's. I suspect their roof prism bins are as bright as they are owing mostly to very high transmission lens coatings and would be even brighter with dielectric mirror coating.

Henry

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Henry: I'm also not sure how many of the 5 surfaces require a mirror coating but you might be right

Regarding silver deposition, surely vapour deposition is the norm, at least in the commercial world. Companies have for decades been using vacuum chambers to apply the normal anti-reflection coatings to lens elements and prisms. I seem to recall that 20 years ago many amateurs astronomers had to resort to chemical deposition to coat their mirrors. I think the metal was silver. I assume that these days most trust a commercial coating facility and choose aluminium, perhaps with a hard coating.

Regarding your comments on the Nikon coatings, you make an interesting comment. It's hard to comment without some solid figures. Do you have any figures for the % transmission of a HG binocular? I have read claims that silver can have reflectivity of more than 98% across the visible spectrum. Swarovski claim better than 99.5% transmission over the entire visible spectrum for each Swarobright mirror surface. So onthe basis of those figures the difference due to the coatings is about 3%. Given that figures from an earlier thread give the % transmission for an EL binocular as being about 84% (I forget the exact value) that suggests that most of the losses are occuring at the surfaces of the lens elements. I don't suppose you have figures from Leica et al for the % transmission at each air glass interface? I seem to recall 0.5% being quoted by Nikon for pro-grade photographic optics but I might be mistaken.

Don't know about the UK, but in the US we've had aluminium coatings commercially applied to amateur-made telescope mirrors since the 1950s.

ranburr said:

Swarovski and Leica attack problems from different ways. Swarovski uses the Swaro-bright lense coatings to achieve a clear bright image. I find the Swaros to give very comfortable viewing for hours at a time. Leica uses a higher grade of ED glass and quality coatings to achieve their view. Both are very good and it depends on who you ask as far as which image is superior. I prefer the Swaro's image, but the Leic is a much tougher and durable bino.

ranburr

ranburr

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Ranburr,

I've heard several folks say that Leica's are more "tougher and durable" than Swarovski's, but I can't figure out why. Why? The SLC series is very tough. (Don't mean to be argumentative, but I'd really like to know the evidence.)

-elk :eek!:

Yes, how can you tell Leica is tougher and more durable than SLC? Anyone dare to drop them from the tenth floor?

Regarding the brightness issue of high-ended binoculars, SE is the best I have ever come across with. Zeiss Victory (10x40) is very bright but still a little bit behind SE. Victory is brighter than competitors possibly because of the AK prism design. However it suffers from excessive color aberration (both on-axis and off axis) and pin-cushion distortion. Some of my friends complained they felt dizziness after using it for a while....... So I sold it on internet to fund my new BR.

I have been told by an optical expert in China that the numbers of inflection inside prisms are not the way we thought. What we saw from pamphlets etc are 2-D cross-section pictures only. In reality, there are totally 6 internal reflections in a Pechan prism and 4 internal reflections in a AK prism, which can only be shown in 3-D diagram. However I can't find any valid reference to justify the claim or vice versa.

leicaeddy said:

I have been told by an optical expert in China that the numbers of inflection inside prisms are not the way we thought. What we saw from pamphlets etc are 2-D cross-section pictures only. In reality, there are totally 6 internal reflections in a Pechan prism and 4 internal reflections in a AK prism, which can only be shown in 3-D diagram. However I can't find any valid reference to justify the claim or vice versa.

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Those particular numbers can't be accurate unless each half of the roof face is being counted as a seperate reflection. Uneven numbers of reflections (1,3,5, etc.) result in upright but reversed images which is why roof prisms need one face to be split in half into a roof shape to correct the reversal.