My musings, with essay questions at the end.
Is it true that decades ago porros achieved equal if not greater light transmission than current roofs, because manufacturers didn't have to deal with the inherent light loss in roof prisms?
From what I can tell, these incremental improvements in roofs, particularly in terms of prism coatings, have been mostly about catching up to porros.
And it's been a very costly effort (just look at prices on alpha bins today - but sit down first, you might get "sticker shock").
The p-coatings technology has trickled down to lower cost models, thanks largely to the industrialization of China.
For example, Swift's Horizon roofs have silver coated prisms, here-there-to the realm of top roofs, and they also have a magnesium alloy frame, ditto in terms of being employed on more expensive models (the Horizons cost $199).
They are also Waterproof, Fogproof & Shockproof, have a close focus of under 4 ft., etc.
I don't know how they compare to top models, but the point is that just as the Honda's VTEC engine trickled down from its sports cars to the economical Honda Fit, top bins' innovations have trickled down to lower cost roofs.
Here's the ad:
http://www.opticsplanet.net/swift-8x...inoculars.html
In a few years, we'll probably see lower cost roofs with dielectric coatings and the Top Three/Four/Five will come up with "nano-coatings" of some such thing.
So while there has been "trickle down economics" in roof prism bins, it was the Big Three (and Nikon) that made most of these innovations, and buyers paid through the nose for the R & D (and perhaps some profit padding) for those incremental improvements, and they are still paying dearly for them with the latest $2K bins from Leica, Zeiss, Swaro (new EL), Nikon EDG, and now Minox with its $1,800 APO HGs.
Could bin manufacturers have gone another way and simply given porros the two things they lacked over roofs - WP/FP?
Now with the Leupold Cascades and Minox BPs, WP/FP with an internal focuser to make it "submersible" at reasonable, not astronomical prices, the gap has been closed.
But it remains to be seen if any other manufacturers follow suit and make such porros with wider fields of view.
Not sure if the Leupold is submersible, but Minox claims that the Minox BP is:
http://www.minox.com/index.php?id=1917
What's your take on all this?
1. Could we have arrived at the point where are in optics now more quickly and much less expensively if bin manufacturers hadn't tried to make porros out of roofs, so to speak, and instead put their innovations into porros?
2. Do you think we are reaching a point of diminishing returns in binocular optics whereby, short of going digital, we've nearly achieved the best light transmission possible, the best contrast and color contrast possible, and all the "bells and whistles," and that from here on in, it will be more about marketing than about innovation?
Speculation is not only welcome, but encouraged!
Thanks for your input.
With light transmission through high end binoculars now above 90 %, there is not much room for increases in brightness. However, there is still plenty left to do to improve image sharpness across the entire field, cut CA further and perhaps widen the field of view without cutting eye relief.
Tools to achieve that might include cast aspheric lenses ( to keep costs out of the stratosphere) as well as possibly diamond milling of the surfaces, to get the needed shapes with appropriate precision on a repeatable basis.
The research to do those things is fostered by unexpected programs such as the laser fusion effort, which has pushed the optics manufacturing state of the art to make lenses that don't melt themselves when huge light pulses pass through them. The fiber optics folks have shown how to make the needed super homogeneous glass in quantity.
So there is good promise of further improvement, but hard won and not cheap.
That suggests the SE fan club can start to plan its 50th anniversary celebration with confidence.
Brock,
I think you're blaming roof prisms for a general turn toward optical and mechanical complexity in all areas of premium binocular design. Roof prism bins used to be pretty simple with cemented doublet objectives and moving eyepieces or objectives for focusing, just like Porros. They could still be made that way and a few are, like the Swarovski 8x30 SLC. Modern Porros could have 4 element objectives, internal focusing lenses, complex eyepieces and high prices. I imagine if Nikon had simply substituted Porros for roof prisms in the EDG binoculars they would be nearly as expensive as they are now.
I just looked at a 2002 Zeiss price list that has the Zeiss 7x50 B/GAT* Porro priced at $1399 and the 8x56 B/GAT* ClassiC roof at $1359. One is roof and one is Porro but the optical and mechanical complexity is similar and so is the price.
Henry