"I remember around 20 years ago reading an article by Bill McRae. He stated that in all the optical testing that he’d done,To further extend the notion of whether a larger non-premium binocular can perform as well as a smaller premium one . . .
I remember around 20 years ago reading an article by Bill McRae. He stated that in all the optical testing that he’d done,
the cheapest 10x50 Porro prism binoculars had shown as much resolution as the most expensive 10x25 roof prism ones *
On reflection Bill’s observation is not all that surprising, since it must be several orders of magnitude more difficult,
to make a 10x25 that can perform perform as well as a 10x50
Firstly, there are obvious physical limitations, including the need for higher magnification lenses to achieve the same focal lengths
within significantly shorter physical lengths
And much more precision would be required both in the production and assembly of the many components
For a quick visual comparison, see a combined image of:
a) a cheap Z style construction Porro 10x50, the Tasco Essentials (US $42 at B&H Photo), and
b) the most compact premium roof prism 10x25, the Leica Ultravid ($900 in the leather finish version shown, $100 less in rubber armour) **
The image demonstrates that classic triangular relationship between: Physical Size (and weight); Performance, and; Cost
* Bill was a long-time writer on optics, mainly in US outdoors magazines. He was also a long-time consultant for Bushnell
** I used an image of the leather finished version for convenience. It had sufficient white space at the top to enable me to easily combine it
with the Tasco image
Probably one reason it seems a good 10x32 is hard to manufacture.Hi Brink (post #60),
There are a multitude of problems related to the production of opto-mechanical devices. For a brief introduction to four areas of concern:
Managing Tolerances; Managing Thermals; Mounting Lenses, and; Dust, Humidity and Contaminants,
see an article by Tristan Dudik at: https://www.simplexitypd.com/blog/4...cal-integration-of-optical-systems-simplexity
The effects of the above on the performance of components, often change with the size of the components
e.g. A 50 mm diameter objective has four times the area of a 25 mm one. So a defect of a given size - such as a tolerance error of 0.01” in concentricity -
will have a much larger effect on the smaller lens
- - - -
Hi JG (post #63),
To describe Bill McRae as a hack, is perhaps not to completely dismiss him as you imply
e.g. see David Barnett on ‘What’s wrong with being a hack?’ at: https://www.theguardian.com/books/booksblog/2009/aug/13/hack-writers
And for what it’s worth, John Barsness dedicated his book Optics For The Hunter 'For Bill McRae, who leads the way'
Those are rare now but better than most 10x32's out there. Nice wide 65 degree AFOV and better at glare control than the EL 10x32. Do you have the EDG 10x32 also?A favorite 10X32 of mine, likely the fastest focus ever made on a premium glass. A "hard" I mean difficult glass to manufacture.
I think John kind of answered that above. Smaller apertures with higher magnifications especially roofs seem to have to be built to very exacting specifications because any imperfection seems to be more highly magnified by the smaller aperture and higher magnification. Have you tried any 10x32?I must have missed the reply to Bill's question about why it is difficult to make a good 10X32.
No, I bought 8X32 to make for steadier images.I think John kind of answered that above. Smaller apertures with higher magnifications especially roofs seem to have to be built to very exacting specifications because any imperfection seems to be more highly magnified by the smaller aperture and higher magnification. Have you tried any 10x32?
Andy. Do those older HG have leaded glass?Mine is the original HG, only 15 grams difference difference to the HG L. They are heavy for some and the weight is in the eye piece. 695 grams. excellent against glare, I believe Kimmo did a review a ways back. I have the 8X32 HG also and still use them.
Yes.Is the 10X42 LX still in good shape?, and do you use it at all?