I wanted to know the interpupillary distance on your Denali 8x42 and Ranger 8X42 binoculars.
I see they both are phase corrected, fully coated, BAK-4 prism lenses.
What is the big difference in these two products?
The IPD of the Ranger 8x42 is 58mm and the Denali is 56mm.
There is quite a bit of difference between these two binoculars, all favoring the more expensive Rangers.
The build quality and mechanics are smoother and more precise on the Rangers. Better focus mechanism, nicer eyecup mechanics, and smoother diopter adjustment.
In addition to the mechanics, the Rangers use a higher quality optical system in regards to the lens grade and lens coatings. There are more lens coatings and higher quality coatings on the Rangers. This all amounts to a binocular that will have better image resolution, more color contrast, and greater light transmission than what we are able to offer in the Denali. I would say that the difference is pretty noticeable and you would not need to consider yourself an optics "expert" to observe the differences.
Hopefully this answers your questions. If there is anything else we can do for you, please don't hesitate to email or call.