New binoculars from leica (1 Viewer)

When i claim green cast on SF many people almost call me a liar.............later on was confirm for many others.

Now the Leica red cast is not there.......well is not there if you don't see it.

As photographer i work a lot with crazy expensive calibrated monitors and i know a little bit about color bias and i am able to see it where others hardy notice it, but differences are there.

Nice review of color bias done by a professional videographer.
All Alphas and models are shown.

http://www.greatestbinoculars.com/allpages/articles/coloursandbrightness.html

I tend to agree that the new binoculars will probably not use Perger Prisms, but here's a little more information for those who are interested.

This German Wikipedia entry shows the "bottleneck" Holger mentioned as a blue shape. That would be the cause of the increase in vignetting at the field edge mentioned in the patent application.

https://de.wikipedia.org/wiki/Perger-Prisma

In order for that blue shape to be large enough to pass the objective lens' light cone without clipping the aperture the entry and exit faces have to made larger than would be needed by Porro 1 or 2, so a Perger has to be larger and heavier to handle the same size light cone.

The Perger's great advantage is the adjustable offset (apparently even zero horizontal offset is possible). That has the potential to solve the problem of excessive parallax at close distances suffered by conventional Porro binoculars.

GLOBETROTTER said:

When i claim green cast on SF many people almost call me a liar.............later on was confirm for many others.

Now the Leica red cast is not there.......well is not there if you don't see it.

As photographer i work a lot with crazy expensive calibrated monitors and i know a little bit about color bias and i am able to see it where others hardy notice it, but differences are there.

Nice review of color bias done by a professional videographer.
All Alphas and models are shown.

http://www.greatestbinoculars.com/allpages/articles/coloursandbrightness.html

Click to expand...

Transmission tests on the 8x42 SF done by Gijs revealed no green color bias.
I haven't looked through SF long enough to make my own impression.

When I was sort of a newbie to BF I read about this bin and that bin
having a yellow or red "tint" or "color cast" and imagined almost a yellowish
or reddish filter over the view.

At one time I was interested in the Alpen Ranier 8x32 since it was said to be similar in
some ways to Leupold Gold Ring. Some here mentioned this yellow tint in the Rainier and
a couple people said they didn't like it. One guy who owned the Ranier PM'd me
and said not to worry about all this "yellow tint" stuff and that it was not "yellow" at all, but more or less a subtle cream color
when looking at white objects. So, I ordered the Rainier and had a look. He was right...it was
a very subtle cream like color , but I had to really look hard to see it against a white background.
I returned the Rainier due to its weight.
It had a nice view though, but after that experience I began to dismiss accounts of bins having
red, yellow , green or blue "tints" to them. If, in reality, a bin does have some color bias in a given
range I know that it will be barely noticeable (to me at least) when looking through the bin.

I found the ultravid HD and the Trinovid I owned (non-HD) to have slightly warm tone.

henry link said:

In order for that blue shape to be large enough to pass the objective lens' light cone without clipping the aperture the entry and exit faces have to made larger than would be needed by Porro 1 or 2, so a Perger has to be larger and heavier to handle the same size light cone.

Click to expand...

Which fits with rumours that Leica dropped the idea of observation binoculars with Perger prisms due to uncompetitive weight.

Lee

GLOBETROTTER said:

When i claim green cast on SF many people almost call me a liar.............later on was confirm for many others.

Now the Leica red cast is not there.......well is not there if you don't see it.

As photographer i work a lot with crazy expensive calibrated monitors and i know a little bit about color bias and i am able to see it where others hardy notice it, but differences are there.

Nice review of color bias done by a professional videographer.
All Alphas and models are shown.

http://www.greatestbinoculars.com/allpages/articles/coloursandbrightness.html

Click to expand...

Well I`v just re-read that article through your link, to me, the UVHD+ is the most neutral, I certainly don`t see a "red" cast, the SF looks greenish and the EII looks very warm next to the UV, which is what I see in use.

I am not going to get into an argument with two professionals about it, but red cast is substantially overstating things IMHO.

Use your bin of choice against fresh, clean snow - if you don't see a colour cast [or anything objectionable], move on and forget it.

Troubador said:

Which fits with rumours that Leica dropped the idea of observation binoculars with Perger prisms due to uncompetitive weight.

Lee

Click to expand...

Probably true, but since prism size doesn't increase proportionately with objective size (not at all if the focal ratio remains the same), I imagine there isn't much, if any, weight penalty with Pergers in 50-56mm binoculars. Even with extra weight from the rangefinder parts the Geovid 8x56 with Perger weighs about the same as the Zeiss 8x56 FL with Abbe-Konig. 42mm Pergers might weigh a little more than A-K or S-P and there is probably just not enough space between the focusing lens and eyepiece field stop for a big enough Perger in a 32mm binocular.

A Leica 8x50-56 with Perger prisms would definitely get my attention.

Henry

henry link said:

I tend to agree that the new binoculars will probably not use Perger Prisms, but here's a little more information for those who are interested.

This German Wikipedia entry shows the "bottleneck" Holger mentioned as a blue shape. That would be the cause of the increase in vignetting at the field edge mentioned in the patent application.

https://de.wikipedia.org/wiki/Perger-Prisma

In order for that blue shape to be large enough to pass the objective lens' light cone without clipping the aperture the entry and exit faces have to made larger than would be needed by Porro 1 or 2, so a Perger has to be larger and heavier to handle the same size light cone.

The Perger's great advantage is the adjustable offset (apparently even zero horizontal offset is possible). That has the potential to solve the problem of excessive parallax at close distances suffered by conventional Porro binoculars.

Click to expand...

Hi Henry,

Apart from the differences in physical space (particularly length, and objective end/ ocular end offset), light path length, and transmission%, do we (BF mob) have, or is there a link to a technical paper, detailing the differences in weight between the different prism types:- S-P vs Porro I & II vs A-K vs Perger ?

A quick look turned up this link to Holger's website http://www.holgermerlitz.de/porros.html which stated that a symmetrical Porro prism would weigh 11% more than an S-P prism. Any data on how the other types compare for handling a light bundle to give the same size FOV ?? :cat:

I read back through some archives and there was a mention that Zeiss at the time claimed a 2% increase in transmission for the A-K over the S-P prisms --- surely Perger prisms would be worthwhile pursuing? I hope Leica surprises us with something really innovative ....... :brains:


Chosun :gh:

henry link said:

A Leica 8x50-56 with Perger prisms would definitely get my attention.

Henry

Click to expand...

I think that would get the attention of all of us.

Lee

Troubador said:

I think that would get the attention of all of us.

Lee

Click to expand...

Attention perhaps, but the question is if it would be interesting enough for enough people to buy. Even Leica gotta pay their bills. The HD-B have an unique ballistic system for hunters, but the optics does not seem much better or worse than Swaro.

The "fact" is that 42mm bins probably have more than 60% of the market. The rest is 32 and 50, 56 etc. Introducing a new model costs R&D etc. I can't recall any new model series started with the release of a 50-56mm?

Leica need an Unique Selling Point for this new bin. The marketing fluff seems pretty vague. I get the impression of a Zeiss HT competitor, would be about 4 years to late I guess.

Ultravids HD+ are already the "best" bins in the world, according to Leica...so making an even better one is always degrading for the current alpha-models price level and status. UV HD+ is already a bit cheaper here than the other alphas so it might be room for a hyper-alpha. Being the most expensive/exclusive is also a valid USP. Leica cameras are a good example of that.

OR Leica will do something completely different, like an odd 9x45, the master of dusk and dawn binocular. But still with a decent FOV, low weight below 780g and a stable view. That would be enough for me to be really interested. A 50mm+ bin above 800 grams would not be.

Vespobuteo said:

Attention perhaps, but the question is if it would be interesting enough for enough people to buy. Even Leica gotta pay their bills. The HD-B have an unique ballistic system for hunters, but the optics does not seem much better or worse than Swaro.

The "fact" is that 42mm bins probably have more than 60% of the market. The rest is 32 and 50, 56 etc. Introducing a new model costs R&D etc. I can't recall any new model series started with the release of a 50-56mm?

Leica need an Unique Selling Point for this new bin. The marketing fluff seems pretty vague. I get the impression of a Zeiss HT competitor, would be about 4 years to late I guess.

Ultravids HD+ are already the "best" bins in the world, according to Leica...so making an even better one is always degrading for the current alpha-models price level and status. UV HD+ is already a bit cheaper here than the other alphas so it might be room for a hyper-alpha. Being the most expensive/exclusive is also a valid USP. Leica cameras are a good example of that.

Click to expand...

VB

I agree absolutely. These are the questions that all brands have to confront. Your point about new and better models degrading existing ones is, I am sure, exactly why Zeiss has tried to aim HT and SF at different markets.

With HD Plus being so recent, I can't believe it will be discontinued so like you I expect the new model to be 'hyper-alpha' or at least up there with SF and EL and maybe even a bit higher. For sure Leica will be keen that Ultravid and HyperVid don't eat each other's market too much.

I wouldn't expect a 50 or 56 as the only first release model either but we don't know whether Leica is planning a stepped release with 42mm first then 32 then 50 then 5? or whether we might get a whole family. Safe money goes on 42mm first but if Leica doing something really new and not evolutionary then who knows? Who? We all will in just a few weeks time.

Lee

I know I'm one of the very few birders in the world who prefers an 8x50-56. I'm dependent on European hunters to keep that configuration alive. If a Leica/Perger like that came along and was superior to my 8x56 FL one sale to a birder would be guaranteed.

Chosun Juan said:

Hi Henry,

Apart from the differences in physical space (particularly length, and objective end/ ocular end offset), light path length, and transmission%, do we (BF mob) have, or is there a link to a technical paper, detailing the differences in weight between the different prism types:- S-P vs Porro I & II vs A-K vs Perger ?

A quick look turned up this link to Holger's website http://www.holgermerlitz.de/porros.html which stated that a symmetrical Porro prism would weigh 11% more than an S-P prism. Any data on how the other types compare for handling a light bundle to give the same size FOV ?? :cat:

I read back through some archives and there was a mention that Zeiss at the time claimed a 2% increase in transmission for the A-K over the S-P prisms --- surely Perger prisms would be worthwhile pursuing? I hope Leica surprises us with something really innovative ....... :brains:


Chosun :gh:

Click to expand...

Hi Chosun,

Sorry, I haven't found anything like that. The patent application is the closest thing to a "technical paper", but I don't see anything in it that could be used to predict exact size and weight compared to other prism types.

Henry

henry link said:

Hi Chosun,

Sorry, I haven't found anything like that. The patent application is the closest thing to a "technical paper", but I don't see anything in it that could be used to predict exact size and weight compared to other prism types.

Henry

Click to expand...

I have collected some data regarding the volumes of different prism types. We have to take these numbers with a grain of salt, however, because all prism types do exist in several different variants.

Assume that the entrance width (the maximum diameter of the beam that can pass the prism entrance without vignetting) is w, then we can easily calculate the volume of a symmetric Porro I system as 2 w^3. Many wide angle binoculars have asymmetric Porros implemented, in which the second prism is of reduced size. It then depends on the details of the optical design (and hence the shape of the light cone) how far one can drive such a weight reduction.

The Porro II has, in its original variant, identical volumes (2 w^3), though Zeiss implemented modifications with reduced weight (as discussed in Hans Seeger, "Zeiss Handferngläser 1919-1946", pages 354ff).

Andreas Perger cites (in a guest-contribution to my book) for a typical incarnation of his Porro design a rather small volume of only 1.37 w^3, quite a bit less than the Porro II. But due to the bottleneck, a larger value of the prism entrance w may be required (again, depending on the shape of the light cone).

The most common Schmidt-Pechan prism has a volume of 1.8 w^3, and the Abbe-Koenig is the most bulky one with 3.72 w^3. I haven't found values for the Uppendahl prism, but estimate its volume around 2.25 w^3.

The weight of the prism then further depends on the density of the glass. BaK4 has a density of 3.10 g/cm^3, while BK7 is less dense with 2.51 g/cm^3. With the Abbe-Koenig prism, but also the Schmidt-Pechan, the two prism elements may be made of different glass types, but I haven't found detailed information about that.

Precise geometries of several prism designs are published in the book of Paul R. Yoder, Jr: "Mounting Optics in Optical Instruments", SPIE Press Bellingham, Washington USA (2008).

In summary, I guess it is close to impossible to estimate the weight of a well optimized prism without referring to the details of the optical design, i.e. the exact shape of the ray pencil, the choice of glass types and the amount of vignetting the designer is willing to accept.


Cheers,
Holger

henry link said:

Hi Chosun,

Sorry, I haven't found anything like that. The patent application is the closest thing to a "technical paper", but I don't see anything in it that could be used to predict exact size and weight compared to other prism types.

Click to expand...

Holger Merlitz said:

I have collected some data regarding the volumes of different prism types. We have to take these numbers with a grain of salt, however, because all prism types do exist in several different variants.

Assume that the entrance width (the maximum diameter of the beam that can pass the prism entrance without vignetting) is w, then we can easily calculate the volume of a symmetric Porro I system as 2 w^3. Many wide angle binoculars have asymmetric Porros implemented, in which the second prism is of reduced size. It then depends on the details of the optical design (and hence the shape of the light cone) how far one can drive such a weight reduction.

The Porro II has, in its original variant, identical volumes (2 w^3), though Zeiss implemented modifications with reduced weight (as discussed in Hans Seeger, "Zeiss Handferngläser 1919-1946", pages 354ff).

Andreas Perger cites (in a guest-contribution to my book) for a typical incarnation of his Porro design a rather small volume of only 1.37 w^3, quite a bit less than the Porro II. But due to the bottleneck, a larger value of the prism entrance w may be required (again, depending on the shape of the light cone).

The most common Schmidt-Pechan prism has a volume of 1.8 w^3, and the Abbe-Koenig is the most bulky one with 3.72 w^3. I haven't found values for the Uppendahl prism, but estimate its volume around 2.25 w^3.

The weight of the prism then further depends on the density of the glass. BaK4 has a density of 3.10 g/cm^3, while BK7 is less dense with 2.51 g/cm^3. With the Abbe-Koenig prism, but also the Schmidt-Pechan, the two prism elements may be made of different glass types, but I haven't found detailed information about that.

Precise geometries of several prism designs are published in the book of Paul R. Yoder, Jr: "Mounting Optics in Optical Instruments", SPIE Press Bellingham, Washington USA (2008).

In summary, I guess it is close to impossible to estimate the weight of a well optimized prism without referring to the details of the optical design, i.e. the exact shape of the ray pencil, the choice of glass types and the amount of vignetting the designer is willing to accept.

Click to expand...

Hi Henry, Holger,

Thanks very much for that, I did half recall a conversation something along those lines - that is exactly what I was looking for - that is fantastic information ! :t: :king:

So Volumes: Perger = ~1.37w^3 < S-P = 1.8w^3 < Porro = 2w^3 < Uppendahl ~= ~2.25w^3 < A-K = 3.72w^3 , all subject to optical design (asymmetry, etc), glass types, and different densities for final weights .....

If the Perger prism needs a wider entrance window of even 10% to compensate for the bottleneck (ie. wp =1.1*w), then it's volume could swell to ~1.8w^3 on a like transmitted light bundle for like basis ..... So S-P level but with the advantage of 100% internal reflection transmission and that unique Porro 'clarity' :king:

The trend to use higher quality, denser glass types (HT, SK15, etc) to eek out the latest incremental advances in transmission will see a trend to heavier prisms, so I think pursuing the Perger is a thoroughly worthwhile innovation ..... I really hope Leica does surprise us! :t:

Chosun :gh:

Thanks for the information, Holger. Looks like I shouldn't wait for an English translation before I buy a copy of your book.

Looking at the figures in the patent application ( https://www.google.com/patents/US20120140349 ) just now it appears to be possible to make some crude approximation of the prism size difference between Perger Porro and Porro Type 2 for the same size light cone diameter measured at the "bottleneck", based on the ratio of bottleneck width to entrance and exit face widths.

For the symmetrical Porro Type 2 the diamters are all the same size (Fig. 2b) The ratio of the diameter of contact surfaces between the prisms and the entrance and exit faces is 1:1. A light pencil of that diameter could pass unvignetted through the prism.

Figures 3b and 4b demonstrate that the ratio of the diameter of the "bottleneck" in the Perger to the diameter of the entrance and exit surfaces is dependent on the amount of offset. It's about 1:1.5 in 3b where there is more offset and about 1:2.5 in 4b with less offset. In other words the illustrated Pergers would need to have entrance and exit faces 1.5 or 2.5 times the diameter of the Porro 2 entrance and exit faces. Notice that in the 4b low offset version the light cone has to enter the first prism and exit the second prism off-center and also the length of the prisms has to increase compared to 3b. Of course, all this would vary with the focal ratio of the objective lens, but these figures appear to offer a reasonable approximation of the size increase with Perger compared to symmetrical Porro 1 or 2 and demonstrate that a Perger configured for lower offset must be made the larger and heavier than one with a higher offset.

Henry

henry link said:

Thanks for the information, Holger. Looks like I shouldn't wait for an English translation before I buy a copy of your book.

Looking at the figures in the patent application ( https://www.google.com/patents/US20120140349 ) just now it appears to be possible to make some crude approximation of the prism size difference between Perger Porro and Porro Type 2 for the same size light cone diameter measured at the "bottleneck", based on the ratio of bottleneck width to entrance and exit face widths.

For the symmetrical Porro Type 2 the diamters are all the same size (Fig. 2b) The ratio of the diameter of contact surfaces between the prisms and the entrance and exit faces is 1:1. A light pencil of that diameter could pass unvignetted through the prism.

Figures 3b and 4b demonstrate that the ratio of the diameter of the "bottleneck" in the Perger to the diameter of the entrance and exit surfaces is dependent on the amount of offset. It's about 1:1.5 in 3b where there is more offset and about 1:2.5 in 4b with less offset. In other words the illustrated Pergers would need to have entrance and exit faces 1.5 or 2.5 times the diameter of the Porro 2 entrance and exit faces. Notice that in the 4b low offset version the light cone has to enter the first prism and exit the second prism off-center and also the length of the prisms has to increase compared to 3b. Of course, all this would vary with the focal ratio of the objective lens, but these figures appear to offer a reasonable approximation of the size increase with Perger compared to symmetrical Porro 1 or 2 and demonstrate that a Perger configured for lower offset must be made the larger and heavier than one with a higher offset.

Henry

Click to expand...

Hi Henry,

I think so - the Perger prism is turning less efficient (in terms of beam-diameter vs. size) while its offset is being reduced. So the designer has that additional parameter to optimize the overall weight and vignetting of his instrument: Low axis offset implies larger prisms, a larger axis offset requires a larger (wider) body of the instrument.

The English translation of my book is going to happen, and I hope to have that done and published by summer 2017..

Cheers,
Holger

Holger Merlitz said:

The English translation of my book is going to happen, and I hope to have that done and published by summer 2017..

Click to expand...

I'm sure you'll generate some sales around here :t: I'm certainly going to buy a copy...

...Mike

Holger Merlitz said:

Hi Henry,

I think so - the Perger prism is turning less efficient (in terms of beam-diameter vs. size) while its offset is being reduced. So the designer has that additional parameter to optimize the overall weight and vignetting of his instrument: Low axis offset implies larger prisms, a larger axis offset requires a larger (wider) body of the instrument.

The English translation of my book is going to happen, and I hope to have that done and published by summer 2017..

Cheers,
Holger

Click to expand...

Great News!

Lee