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Abbe-König versus Schmidt with dielectric coatings (1 Viewer)

[email protected] said:
"But will the profits make it worthwhile?" Sure! Just ask the Swarovski family. Watch how much the next generation of Zeiss FL's will be. More profits more R&D money more improvements.
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As other manufacturers introduce alpha class optics in the next year for well less than half what the big 4 are charging, we'll see how the profits go. I actually think we will see one or two of them before years end.

And the SV's don't seem to be selling on ebay like hotcakes - (7) 10x42's & (1) 8.5x42 sold. For every buyer of a hotcake, their is a seller getting rid of a hot potato. Wonder why these people are flocking to get rid of their SV's ?

Tom
 
lilcrazy2 said:
As other manufacturers introduce alpha class optics in the next year for well less than half what the big 4 are charging, we'll see how the profits go. I actually think we will see one or two of them before years end.

And the SV's don't seem to be selling on ebay like hotcakes - (7) 10x42's & (1) 8.5x42 sold. For every buyer of a hotcake, their is a seller getting rid of a hot potato. Wonder why these people are flocking to get rid of their SV's ?

Tom
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I think Zeiss will bring out a new binocular to compete with the SV in about a year or so and they seem to undercut Swarovski in price so I would expect it to be about $2K. 8 $2k binoculars is alot for E-bay! That's $16K! You know how many Olympus Trackers that would buy. 320 Trackers. Also, alot of the sellers sellling Swarovision's are big stores and dealers. Eagle Optics, Euro Optics, etc. It's not alot of private sellers unloading them already. Some people get them as gifts and decide they would rather have something else that cost $2K or thereabouts.
 
Dennis
Of the 8 sold - 1 was "new" the other 7 used.

Your enthusiam is understandable. I looked back at your comments from the time you first got them up till today. It reminds me of a runaway train building up a head of steam. You seemed quite calm about them in the beginning, and they just keep getiing better and better.
 
lilcrazy2 said:
Dennis
Of the 8 sold - 1 was "new" the other 7 used.

Your enthusiam is understandable. I looked back at your comments from the time you first got them up till today. It reminds me of a runaway train building up a head of steam. You seemed quite calm about them in the beginning, and they just keep getiing better and better.
Click to expand...

The more I use them the more I appreciate them. I am suprised how well you can see in shadows with them. There performance just keeps surprising me.
 
lilcrazy2 said:
Dennis
Of the 8 sold - 1 was "new" the other 7 used.

Your enthusiam is understandable. I looked back at your comments from the time you first got them up till today. It reminds me of a runaway train building up a head of steam. You seemed quite calm about them in the beginning, and they just keep getiing better and better.
Click to expand...

I sorted them by new and used and 5 were new and 3 were used. Check your numbers! And what is surprising is the used ones sold for as much as the new ones. There really holding there value!

NEW
http://completed.shop.ebay.com/i.ht..._fln=1&_ssov=1&_trksid=p3286.c0.m282&saveon=2

USED
http://completed.shop.ebay.com/i.ht...inocular&_fln=1&_ssov=1&_trksid=p3286.c0.m282
 
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of the 5 that say new - 1 is a mint open box item and the other 4 are being sold as new by two different pawnshops, who will also sell you a bunch of powertools and Imacs, or a whole bunch of junk. I guess you are right and that they must be new - after all thats what they say. Wonder if they'd throw in a used Imac as well?
 
lilcrazy2 said:
of the 5 that say new - 1 is a mint open box item and the other 4 are being sold as new by two different pawnshops, who will also sell you a bunch of powertools and Imacs, or a whole bunch of junk. I guess you are right and that they must be new - after all thats what they say. Wonder if they'd throw in a used Imac as well?
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4 out of the 5 are E-bay Top Rated Seller's. What more could you ask for?
 
Typically when Dennis says better and better things about his latest binocular it has meant that he is about to sell it. My guess is that he has already decided to buy (or bought) a 50mm SV and is going to place his 42 on the market soon. But I could be wrong of course.

Kimmo
 
If I can leave the fanboy ravings for a moment and return to Hermann's original question, a source at Zeiss told me that the the FL models with Abbe-Konig prisms have about 2% higher transmission than the FL models using Schmidt-Pechan prisms with dielectric coatings. That should be solely attributable to the prism designs since the type of AR coatings and the number of glass to air surfaces are the same otherwise. The difference could be increased a little by cementing the AK prism, which can't be done with an SP.

If the highest light transmission were the first priority a designer wouldn't choose any of the current alpha roof prism designs, certainly not the Swarovski SV, which uses the least efficient prism and a complex design with perhaps 20 glass to air surfaces. The most efficient design would use a cemented Porro or AK, a simple eyepiece and a cemented doublet objective for a total of 8-10 surfaces. Swarovski actually made such binoculars in the past, the SL Porros, and the Docter Nobelim Porros still use a design like that today.
 
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henry link said:
If I can leave the fanboy ravings for a moment and return to Hermann's original question, a source at Zeiss told me that the the FL models with Abbe-Konig prisms have about 2% higher transmission than the FL models using Schmidt-Pechan prisms with dielectric coatings. That should be solely attributable to the prism designs since the type of AR coatings and the number of glass to air surfaces are the same otherwise. The difference could be increased a little by cementing the AK prism, which can't be done with an SP.

If the highest light transmission were the first priority a designer wouldn't choose any of the current alpha roof prism designs, certainly not the Swarovski SV, which uses the least efficient prism and a complex design with perhaps 20 glass to air surfaces. The most efficient design would use a cemented Porro or AK, a simple eyepiece and a cemented doublet objective for a total of 8-10 surfaces. Swarovski actually made such binoculars in the past, the SL Porros, and the Docter Nobelim Porros still use a design like that today.
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Sure a more complex optical system with more air to glass surfaces is going to absorb more light and in the past the AK prism has been known to be more efficient in light transmission. The point here is that Schmidt-Pechan prisms with the proper coatings have equaled the AK prism in transmission so no longer can you assume an AK prism binocular to have better light transmission. Grow up Henry we don't need to resort to name calling! It's childish and it really doesn't add to the thread and just causes ill feelings. Fanboy! What is that!
 
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kabsetz said:
Typically when Dennis says better and better things about his latest binocular it has meant that he is about to sell it. My guess is that he has already decided to buy (or bought) a 50mm SV and is going to place his 42 on the market soon. But I could be wrong of course.

Kimmo
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No, I have no plans to get the 50mm. It is over my weight limit. I learned my lesson with the Zeiss 56mm. It was too heavy.
 
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[email protected] said:
The point here is that Swarovski has equaled the Zeiss AK prism in transmission even with it's complex optical system and inefficient prism so no longer can you assume an AK prism binocular to have better light transmission. Quite an achievment and that is the point of this thread.
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No, that isn't the point of this thread at all. At least it wasn't before you hijacked it to tell everyone who wants to know (and everyone who doesn't) that your latest great love is the best binocular ever made. At least until you come across you next great love. All this is irrelevant to the rather technical question I asked when I started this thread.

This habit of yours, posting the same stuff over and over again ad nauseam, no matter whether it's relevant to the topic of a thread or not, is pretty irritating and getting close to spamming IMO.

Hermann
 
Hermann said:
No, that isn't the point of this thread at all. At least it wasn't before you hijacked it to tell everyone who wants to know (and everyone who doesn't) that your latest great love is the best binocular ever made. At least until you come across you next great love. All this is irrelevant to the rather technical question I asked when I started this thread.

This habit of yours, posting the same stuff over and over again ad nauseam, no matter whether it's relevant to the topic of a thread or not, is pretty irritating and getting close to spamming IMO.

Hermann
Click to expand...

I don't think it is irrelevant. The thread is discussing what prism is more efficient. We are using the Swarovision as an example of one type of prism and the Zeiss FL as another and comparing their light transmissions. How else will you arrive at a conclusion as to which is superior in light transmission. The tests show they are about equal on the two binoculars so we know they are equal with neither one having a marked advantage. The thread did go another way but I don't think it was necessarily my fault. Sorry if you thought I hijacked your thread.
 
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I can't help but note that if two binoculars have exactly the same measured transmission value, for example, 92%, they may still produce different brightness. That's because brightness is a perceptual response that is determined by the distribution of transmitted frequencies, not simply the absolute amount of light. To determine the perceptual response one multiplies the transmission vector by the visual sensitivity function, which, of course, also varies from person to person.

There is an unfortunate tendency to avoid confronting complex processes by using oversimplified measurements, and to assume that one's own perception somehow defines "reality" for everyone else.

Ed :smoke:
 
So, returning to the original post, in addition to total transmission I would also be interested to know if there is a difference in the characteristics of the transmitted distribution between A-K and S-P prisms.

Ed
 
elkcub said:
So, returning to the original post, in addition to total transmission I would also be interested to know if there is a difference in the characteristics of the transmitted distribution between A-K and S-P prisms.

Ed
Click to expand...

That is very interesting. Explains why one binocular seems brighter even though light transmission might be the same. I think there are other factors that come into play also like contrast besides absolute transmission. Are you saying if one type of prism has a more even light distribution in intensity or lumens it would appear brighter or are you talking distribution of different wavelengths of light.
 
I just got one of those Docters and verily, fire shoots out the back. It is, at last, the large binocular of my dreams! That's my fanboy rave of the week.

In 1991, an article in SPIE volume 1533, by Konrad Seil of Swarovski described, among other things, an interesting aspect of Schmidt-Pechan prisms. The first face that the beam enters through also serves as a total internal reflector. The problem is, that at least at that time, the application of antireflection multilayer coatings to that surface degraded the resolution of the binocular. MTF plots with different kinds of coatings were shown. The best compromise at that time was, to apply only a single MgF2 coating to that surface. This diminished transmission a little compared to multicoatings, but preserved the resolution, which Swarovski felt was the main thing. I wonder if this situation has been improved. If not, that's a percent or two right there, never mind the efficiency of the dielectric coat, on another surface.

Another question I have, that pertains to both AK and SP prisms regards the phase correcting coatings. What is their reflectivity? Being made of dielectric material, they "could" be excellent, I guess, but I never saw this discussed anywhere, other than speculation.

All in all, if you take the glass transparency, AR Multicoat, and best dielectric reflective coating claims literally, you wind up wondering why the transmission of the best binoculars is so LOW.
Ron


PS, I am not sure that the face of the SP that does double duty transmission/internal reflection is the first entrance face, but one of the faces does this, so the basic situation is as I described.
 
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henry link said:
If I can leave the fanboy ravings for a moment and return to Hermann's original question, a source at Zeiss told me that the the FL models with Abbe-Konig prisms have about 2% higher transmission than the FL models using Schmidt-Pechan prisms with dielectric coatings. That should be solely attributable to the prism designs since the type of AR coatings and the number of glass to air surfaces are the same otherwise. The difference could be increased a little by cementing the AK prism, which can't be done with an SP.
Click to expand...

That's interesting. So the dielectric coatings have effectively narrowed the gap between binoculars with Abbe-König and Schmidt-Pechan prisms quite a bit. A 2% difference isn't all that much.

henry link said:
If the highest light transmission were the first priority a designer wouldn't choose any of the current alpha roof prism designs, certainly not the Swarovski SV, which uses the least efficient prism and a complex design with perhaps 20 glass to air surfaces. The most efficient design would use a cemented Porro or AK, a simple eyepiece and a cemented doublet objective for a total of 8-10 surfaces. Swarovski actually made such binoculars in the past, the SL Porros, and the Docter Nobelim Porros still use a design like that today.
Click to expand...

This partly explains why some old binoculars with simple coatings still perform quite well. By the way, I think the current Swarovski Habicht porros, especially the 7x42 with its simple eyepieces, are another example of a highly efficient design with a minimum number of glass to air surfaces.

Of course I realize that measured light transmission is only one factor. The transmitted frequencies and the transmission at different frequencies are at least as important, and perceived brightness may be quite different from measured transmission. The Leica HD range seems to my eyes quite bright, especially in the right kind of light, although the measured transmission values are lower than those of some of Leica's competitors. The Nikon HG range, despite it's Schmidt-Pechan prisms and "oldfashioned" silver coatings on the prisms, isn't really "dim" compared to binoculars with higher transmission values and provide a very pleasing image.

But what these figures show is that in two otherwise identical binoculars Abbe-König prisms (and of course porro prisms) are still superior to Schmidt-Pechan prisms, despite modern dielectric coatings. Whether that superiority makes a visible difference in the field, is another matter. I think it may do, in some situations, but I'm not sure.

However, things may well be different in scopes. With scopes I think the choice of prisms may well be more important than with binoculars.

Hermann
 
ronh said:
Another question I have, that pertains to both AK and SP prisms regards the phase correcting coatings. What is their reflectivity? Being made of dielectric material, they "could" be excellent, I guess, but I never saw this discussed anywhere, other than speculation.
Click to expand...

Well, this opens another Pandora's box. Are all phase corrections coatings equally efficient? I'm not sure about that myself. And do any such differences in their efficiency - if they do exist - make a visible difference in binoculars? Or in scopes with roof prisms, with their much higher magnification?

Hermann
 
[email protected] said:
That is very interesting. Explains why one binocular seems brighter even though light transmission might be the same. I think there are other factors that come into play also like contrast besides absolute transmission. Are you saying if one type of prism has a more even light distribution in intensity or lumens it would appear brighter or are you talking distribution of different wavelengths of light.
Click to expand...

I'm not sure if I'm following the question, but a residual light loss of any amount may have very different perceptual consequences, e.g., brightness, color tone, contrast, and so forth, depending upon the particular light frequencies involved. That, of course, would apply to losses at the prisms or anywhere else throughout the instrument. Ultimately, however, all design efforts must face the harsh reality of human variability, which limits the extent to which a product can ever gain universal acceptance based only on engineering merit.

In my opinion at this point we tend to pay far to much attention to optical "perfection," and far too little to our own perceptual and learning abilities.

Ed
 
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