Difference between Phase-correcting P-coating and SWAROBRIGHT? (1 Viewer)

[moyang_mm]

Just out of curiosity, what is the difference between the two, Phase-correcting P-coating and SWAROBRIGHT?

From EL series' product page, for example

https://www.bhphotovideo.com/c/product/1176824-REG/swarovski_32208_8x32_el_binocular_with.html

both types of coating are mentioned:

SWAROBRIGHT coatings provide enhanced contrast, brightness, and color fidelity
SWAROTOP coatings on lenses and prisms reduce light reflection to improve brightness and contrast
Phase-correcting P-coating further improves color and contrast
SWARODUR outer coating on optics helps to prevent scratches and abrasions
SWAROCLEAN non-stick coatings make cleaning dirt, dust, sap, moisture, and fingerprints from lens surfaces easy and fast

In contrast, CL series doesn't seem to have P-coating and SWAROCLEAN.

Swarovski Optical Coatings:

SWAROBRIGHT phase-correcting prism coating eliminates internal interference to improve contrast and resolution
SWAROTOP anti-reflective multi-coating maximizes light transmission, improves contrast and clarity
SWARODUR exterior lens coatings offer scratch-resistance while allowing dirt, dust, oils, and sap to be easily cleaned off without leaving residue to ensure clear and smudge-free views

Notice that here SWAROBRIGHT is described as "phase-correcting", which really confuses me.

Are these two coatings are the same thing, or P-coating is something else that only exists in EL?

 

[John A Roberts]

Hi m_mm,

Regardless of what's on the BH Photo site . . .

Swarotop
Is Swarovski’s term for multilayer anti-reflective coating. it’s applied to all air-to-glass surfaces to aid transmission
With binoculars, 3 layers per surface are sufficient to cover the full visible spectrum (in contrast, camera lenses may have 6 or more layers on each surface)
With current binoculars, different composition layers are used on different surfaces, to give better colour rendition across the spectrum


Swarodur
Is a hard coating applied over Swarotop on the external objective and eyepiece surfaces


Swaroclean
Is a low friction/ easy clean coating applied over Swarodur


P-coating
Phase coating is applied to the two roofed surfaces of a roof prism pair. It corrects the de-phasing (slight unsharpness) of the image
It was the most significant development in improving roof prism image quality


Swarobright
Is dielectric prism coating. It’s applied to the non-Total Internal Reflection surface present on most roof prisms (excepting Abbe-Koenig prisms)
It results in an image with more vibrant colours. It is often 30 layers or more!

The combination of phase and dielectric coatings enables roof prisms to have an image that equals, but does not exceed, that of a quality Porro prism pair

- - - -

All current Swarovski roof prism binoculars including the CL’s have phase coating, whether it's mentioned or not
- the absence would be immediately apparent to any knowledgable person looking through them, and so would feature prominently in any review of a unit

I too have noted that the information about the CL’s typically doesn’t indicate the use of Swaroclean (and I wouldn't be overly concerned if they weren’t so coated)
However, for what it's worth, I’ve seen one spec sheet that does indicate the use of Swaroclean - see below


John


p.s. for technical details it's best to start with Swarovski's own website at: https://aa.swarovskioptik.com/birding

 

[Tringa45]

I too have noted that the information about the CL’s typically doesn’t indicate the use of Swaroclean (and I wouldn't be overly concerned if they weren’t so coated)
However, for what it's worth, I’ve seen one spec sheet that does indicate the use of Swaroclean - see below

John,

I suspect that this is just another case of the marketing people not being fully informed. My wife's CL Companion (manufactured late 2018) does not have Swaroclean, but as you say, that is of no concern.

John

 

[SeldomPerched]

The combination of phase and dielectric coatings enables roof prisms to have an image that equals, but does not exceed, that of a quality Porro prism pair

- - - -

[/url]

Good morning, John.

I was interested by what you say in the quote I extracted above. I don't know diddly squat really about the physics of optics but it intrigues me to know why it is possible to use coatings to reach the standard of Porros while definitely not going beyond.

Tom

 

[jring]

Hi,

iirc Swarobright includes MC coatings on lenses and phase coating on roof prisms. Swarotop means dielectric coatings on the reflective surfaces of roof prisms as opposed to silver ones w/o.

Same with Zeiss - they don't mention phase coatings any more with modern roofs, but that doesn't mean that they don't have it... So you might find a Victory FL 8x32 marked T* (for multicoatings) but not P (formerly for phase coating) but will certainly be phase coated...

Joachim

 

[John A Roberts]

Hi Tom (post #4),

There seems to be a common assumption that since roof prism binoculars are ‘better’ than traditional Porro style ones
- they have a more compact profile, are usually internal focus and also have various convenience features such as adjustable eyecups -
then their prisms must also be optically better

However, as a general optical principle, the simplest solution that produces an acceptable outcome is best. And Porro prisms provide that solution

Since Porro prisms don’t have a roof - where the light column is split and then recombined - then there is no de-phasing, and therefore no need for correction

And as all four reflective surfaces of Porro prisms have total internal reflection (the uncoated surfaces act as perfect mirrors),
then there is no need for reflective coatings to prevent light loss - verses the need for dielectric coating on one surface of most RP’s

So at best, the use of coatings on RP’s to address deficiencies, enables them to reach the level of Porro prism performance *


Another neglected point is that RP's must be manufactured to a much higher degree of precision than Porro prisms, to achieve equal optical performance
Back in the 1980’s it was often noted in popular articles, that the required degree of alignment of Porro prism faces is to within around 2 minutes of angle
In contrast, the alignment required of RP faces is to within around 2 to 3 seconds of angle
- so RP production requires around 50 times as much precision! (120 seconds divided by 2 to 3 seconds)

And while computerised automated cutting and polishing technology may enable RP tolerances to be routinely met, the difference still remains


In total, the above helps to explain why especially at lower price levels, RP binoculars don’t equal the optical performance of Porro ones


John


p.s. I’ve previously posted in some detail about the development of roof prisms, see from post #28 on at: https://www.birdforum.net/showthread.php?p=3935264

* However, as noted at the end of post #33 in the above link, the commonly used Schmidt-Pechan prisms have a deficiency that makes this unlikely
- the 2 facing surfaces must perform both transmission and reflection functions!

 

[mooreorless]

I had to look at the date of this thread just to make sure it was not an old thread. Nice thread it is always good to let people know . I have quite a few porro prism binoculars and Roof of course.

 

[SeldomPerched]

Hi Tom (post #4),

There seems to be a common assumption that since roof prism binoculars are ‘better’ than traditional Porro style ones
- since they have a more compact profile, are usually internal focus and also have various convenience features such as adjustable eyecups -
then their prisms must also be optically better

However, as a general optical principle, the simplest solution that produces an acceptable outcome is best. And Porro prisms provide that solution

Since Porro prisms don’t have a roof - where the light column is split and then recombined - then there is no de-phasing, and therefore no need for correction

And as all four reflective surfaces of Porro prisms have total internal reflection (the uncoated surfaces act as perfect mirrors),
then there is no need for reflective coatings to prevent light loss - verses the need for dielectric coating on one surface of most RP’s

So at best, the use of coatings on RP’s to address deficiencies, enables them to reach the level of Porro prism performance *


Another neglected point is that RP's must be manufactured to a much higher degree of precision than Porro prisms, to achieve equal optical performance
Back in the 1980’s it was often noted in popular articles, that the required degree of alignment of Porro prism faces is to within around 2 minutes of angle
In contrast, the alignment required of RP faces is to within around 2 to 3 seconds of angle
- so RP production requires around 50 times as much precision! (120 seconds divided by 2 to 3 seconds)

And while computerised automated cutting and polishing technology may enable RP tolerances to be routinely met, the difference still remains


In total, the above helps to explain why especially at lower price levels, RP binoculars don’t equal the optical performance of Porro ones


John


p.s. I’ve previously posted in some detail about the development of roof prisms, see from post #28 on at: https://www.birdforum.net/showthread.php?p=3935264

* However, as noted at the end of post #33 in the above link, the commonly used Schmidt-Pechan prisms have a deficiency that makes this unlikely
- the 2 facing surfaces must perform both transmission and reflection functions!

Hi John,

Thanks for this excellent explanation. I see now exactly what you meant.

But I'll have to resist the temptation to get a Habicht just yet... and then which one?

And if you don't mind another question, does what you say about manufacturing tolerances come to mean in your experience that a porro will take rougher treatment without going out of optical alignment - collimation or any other jolt to the seating of the components that affect the optical path?

All the best,

Tom

 

[moyang_mm]

Thanks for the excellent explanation, John.

I too have noted that the information about the CL’s typically doesn’t indicate the use of Swaroclean (and I wouldn't be overly concerned if they weren’t so coated)
However, for what it's worth, I’ve seen one spec sheet that does indicate the use of Swaroclean - see below

I've received reply from Swarovski Optik (see below), the leaflet you post indeed contains an error.

thank you for your mail.
We apologize for the confusion, in fact an error has occurred here.
The following coatings are with the CL Companion:
SWAROBRIGHT, SWARODUR and SWAROTOP
SWAROCLEAN is not integrated in the compact binoculars.
We will have this corrected as soon as possible on our homepage.

Bets regards,



Cornelia
Customer Service

SWAROVSKI OPTIK Vertriebs GmbH
Daniel-Swarovski-Straße 70
6067 Absam, Austria
Tel. 00800 32 42 50 56
[email protected]
SWAROVSKIOPTIK.COM