Visual effects in binoculars when used with polarisers (1 Viewer)

[hopster]

I have noticed that using my Leica Noctivid 8x with polarised sunglasses creates weird (but quite pleasant!) optical effects on sunny days. I have not yet noticed this with other binoculars; either porros or roofs. I have not yet explored more carefully with a camera circular polarising filter but plan to as I'm interested to better understand the cause. Any thoughts or knowledge about this from those here who understand the optical issues?

I am assuming that Leica don't just use polarisation to get their famously saturated colours, but clearly something is going on. Perhaps it is the coatings used in the S-P prisms interacting with the polariser somehow?

M

 

[YuShan]

I have no experience with this, so I don't know exactly what kind of improvement you are seeing. I'm also not an expert on this to say the least. But as far as I know, reflection partially polarises the light, so I can image that when viewing through a combination of binoculars and polarising glasses you could see certain effects happening.

 

[tenex]

What do these effects look like? A polarizer can reveal absence of phase coating on roof prisms, but generally when that's present it seems to have no effect.

 

[hopster]

What do these effects look like? A polarizer can reveal absence of phase coating on roof prisms, but generally when that's present it seems to have no effect.

From memory I would say blue-green-turquoise colour shifts and apparently metallic surfaces, particularly on glary subjects like sea water and foliage in sunny conditions.

 

[agus_m]

From memory I would say blue-green-turquoise colour shifts and apparently metallic surfaces, particularly on glary subjects like sea water and foliage in sunny conditions.

The water reflections are partially polarised, sometimes it can be 100% polarised. Maybe when you rotate the binos, the prisms change the polarization.

 

[hopster]

The water reflections are partially polarised, sometimes it can be 100% polarised. Maybe when you rotate the binos, the prisms change the polarization.

I'm used to the effects of polarisers on water and clouds etc from sunglasses and using them for artistic reasons on cameras, but the effects I see through the NVs are rather different. I should try rotating the binos next, and take my camera polarisers to see how that changes things.

 

[Maljunulo]

This is another reason why I wish binocular manufacturers threaded their product so we could use filters.

One I would try a pair of would be polarizers.

 

[Ignatius]

This is another reason why I wish binocular manufacturers threaded their product so we could use filters.

One I would try a pair of would be polarizers.

And I would try out whether the blue distant haze can be better cut with the traditional yellow filters of CZJ and Hensoldt-Zeiss, or with UV or KR filters, the effectiveness of both of which many professional photographers deny.
(From my love for IR photography I can attest to the haze-cutting effectiveness of IR filters - but you'd see sweet f.a. through your binos.)

 

[William Lewis]

Polarized glasses can have some strange effects particularly with roof prism binoculars, partially due to the phase coatings. They can also be used to test if a roof prism binoculars has phase coatings - Post in thread 'Polarised sunglasses and binoculars.' Polarised sunglasses and binoculars.

 

[pbjosh]

I notice this while using polarized sun glasses. It is extremely problematic / annoying when on the ocean / birding on the water. The color shift is so distracting that I purposefully bought non-polarized sunglasses for pelagic birding. It seems worse with some binoculars than others but it's present in basically all of my modern roof-prism bins.

 

[has530]

This is another reason why I wish binocular manufacturers threaded their product so we could use filters.

One I would try a pair of would be polarizers.

Some are! The ones I have had that I tried them with are the Fujinon HC and Canon 15x50 IS.

 

[Hermann]

The ones I have had that I tried them with are the Fujinon HC and Canon 15x50 IS.

Canon 10x42 IS.

Hermann

 

[Lerxst]

I have noticed that using my Leica Noctivid 8x with polarised sunglasses creates weird (but quite pleasant!) optical effects on sunny days. I have not yet noticed this with other binoculars; either porros or roofs. I have not yet explored more carefully with a camera circular polarising filter but plan to as I'm interested to better understand the cause. Any thoughts or knowledge about this from those here who understand the optical issues?

I am assuming that Leica don't just use polarisation to get their famously saturated colours, but clearly something is going on. Perhaps it is the coatings used in the S-P prisms interacting with the polariser somehow?

M

It is indeed the phase correction coatings. I've been thinking about this topic recently as well and I wrote up a meandering post on it as a continuation to my earlier ramblings on the root cause of the roof prism resolution degradation. It is here:

The Physics of Roof Prism and Phase Coatings, Simplified: Polarization Effects - Physics, Birding and Blindness

[latexpage] Many binoculars utilize roof prisms to keep the light along a single optical axis, making for a more compact shape. But the novel geometry of the prism's reflecting surfaces creates a subtle interference effect which reduces the binocular's resolution. The only way to mitigate this...

legallyblindbirding.net

I'm impressed you see the effects during normal use. I've tried on sunny days and I don't see much in my Leupold bins. But my eyesight is extremely poor. Looking through the objectives, the color pops right out, though.

 

[tenex]

It seems worse with some binoculars than others

This could indicate different coating techniques according to the manufacturer... but likely not intended to address this particular effect, so one wonders whether some are subtly more effective at reducing overall phase interference, or others are just cheaper.

 

[hopster]

I notice this while using polarized sun glasses. It is extremely problematic / annoying when on the ocean / birding on the water. The color shift is so distracting that I purposefully bought non-polarized sunglasses for pelagic birding. It seems worse with some binoculars than others but it's present in basically all of my modern roof-prism bins.

Interesting. I have only noticed it strongly in the Noctivids. I must check the Zeiss VP 8x25 and Meostar 12x50 HD and see how they fare.

 

[hopster]

It is indeed the phase correction coatings. I've been thinking about this topic recently as well and I wrote up a meandering post on it as a continuation to my earlier ramblings on the root cause of the roof prism resolution degradation. It is here:

The Physics of Roof Prism and Phase Coatings, Simplified: Polarization Effects - Physics, Birding and Blindness

[latexpage] Many binoculars utilize roof prisms to keep the light along a single optical axis, making for a more compact shape. But the novel geometry of the prism's reflecting surfaces creates a subtle interference effect which reduces the binocular's resolution. The only way to mitigate this...

legallyblindbirding.net

I'm impressed you see the effects during normal use. I've tried on sunny days and I don't see much in my Leupold bins. But my eyesight is extremely poor. Looking through the objectives, the color pops right out, though.

Will have a look at this, thanks.