What is phase coating?
- Thread starter 762shooter
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Easiest to do a search on google ... not sure too many people really know the physics behind phase coating. Certainly I don't. According to the experts it improves roof prism performance. It is not required on porroprism binoculars. I have had several older roof prism bino's (pre phase coating) and they were never quite as sharp or contrasty as the same vintage porroprism bino's.
It is claimed that phase coating has helped roof prism bino's to approach the porroprism design in sharpness and contrast.....there are lots of folks that say this is a very important development for that reason. Also if buying roof prism ... they say to make sure they have phase coating....etc
It is claimed that phase coating has helped roof prism bino's to approach the porroprism design in sharpness and contrast.....there are lots of folks that say this is a very important development for that reason. Also if buying roof prism ... they say to make sure they have phase coating....etc
Like AP said, it is a special coating that helps getting the right colors in the right places, creating an image good enough for us to enjoy. Porroprism are superior for range estimation and depth perception... reason for they will be around for long still.
A binocular has to do the same thing as a telescope, but without the lenght.
Prism binos don't have the frog legs, so distoting the image so much gets it blurry... too many refraction surfaces. Phase coating puts the superimposed images (previously "broken" by the prisms) in the same plan with accuracy.
You want it!!! You can't be without one in a Prism binocular. Try Wallmart 25$ binoculars and see.
You're looking at a minimum of300$, BUT they last a lifetime! You only buy them once!
I got a Leupold 8x40. Paid 350 U$ for it, but I only cried once. I now have a binocular. I can scout for hours with my eyes glued to it...no problem. With a bad one, your eyes will try to compensate for chromatic and plane focusing aberations. in less then 15 minutes, you'll get a headacke. In 10 years, considering all the aspirins, you save big.
If you can shed money for a swaro, or Zeiss, then you got to know that looking thru them are actually a rest exercise for your eyes. Like eating candy
A binocular has to do the same thing as a telescope, but without the lenght.
Prism binos don't have the frog legs, so distoting the image so much gets it blurry... too many refraction surfaces. Phase coating puts the superimposed images (previously "broken" by the prisms) in the same plan with accuracy.
You want it!!! You can't be without one in a Prism binocular. Try Wallmart 25$ binoculars and see.
You're looking at a minimum of300$, BUT they last a lifetime! You only buy them once!
I got a Leupold 8x40. Paid 350 U$ for it, but I only cried once. I now have a binocular. I can scout for hours with my eyes glued to it...no problem. With a bad one, your eyes will try to compensate for chromatic and plane focusing aberations. in less then 15 minutes, you'll get a headacke. In 10 years, considering all the aspirins, you save big.
If you can shed money for a swaro, or Zeiss, then you got to know that looking thru them are actually a rest exercise for your eyes. Like eating candy
The phase coating is only needed in the roof prisms because the light is reflected in them an odd number of times and the various colours (i.e. wavelengths) focus at slightly different distances after an odd number of reflections. The phase coatings correct this loss of sharpness. In a porro prism design, the light is reflected an even number of times and the phase shift of the various wavelengths cancels itself out, therefore the phase coating is not needed.
The short answer? Get the phase coated model. It wasn't more than a few years ago that phase coating was available only in the very top-of-the-line, $1000+ models from high end manufacturers. Nowadays everyone offers it in binoculars selling for only a few hundred bucks. Well worth the money.
John
The short answer? Get the phase coated model. It wasn't more than a few years ago that phase coating was available only in the very top-of-the-line, $1000+ models from high end manufacturers. Nowadays everyone offers it in binoculars selling for only a few hundred bucks. Well worth the money.
John
For the purist (with good enough eyes.. or instruments to measure with) there is a lot more than simply ...is it phase corrected or not?
eg there are at least two types of roof prisms in use by binocular manufacturers: Pechan and Abbe-Koenig;
This is not the case with Abbe-Koenig (or porroprisms for that matter)...
Also it is possible that poorly applied Phase ("P") correction coating can impede not improve your view...it has been observed (on even some high priced bino's) that "P" coating was not applied consistantly to both "sides" of the binoculars showing different diffraction effects.
Personally I stick with good porroprisms although I have some Leitz roof prism binos ...but the 7x,50 benefit less from P coating than say a 10x,40 or an 8x,30 roof
eg there are at least two types of roof prisms in use by binocular manufacturers: Pechan and Abbe-Koenig;
This is not the case with Abbe-Koenig (or porroprisms for that matter)...
Also it is possible that poorly applied Phase ("P") correction coating can impede not improve your view...it has been observed (on even some high priced bino's) that "P" coating was not applied consistantly to both "sides" of the binoculars showing different diffraction effects.
Personally I stick with good porroprisms although I have some Leitz roof prism binos ...but the 7x,50 benefit less from P coating than say a 10x,40 or an 8x,30 roof
