oleaf said:
Companies design and produce products to meet price points and the margin they need to make is figured before.
Well, except for duties to the shareholders, companies don't have a "margin they need to make". They price their products to
maximise profit: the more the merrier. Nikon's High Grade binoculars used to be much more expensive than they are now; the price has come down because Nikon can make more profit by selling more binoculars at a lower margin, i.e. they couldn't sell enough at Zeiss-like prices, for the simple reason that customers prefer to buy Zeiss (or Leica or Swarovski) at that price.
Tim Allwood said:
they consider the HG 8 x 32 to be the best birding bins available with the best resolution score and better contrast (even better than 8.5 ELs) of any bin they've ever tested.
"Contrast" as used above seems to refer to suppression of flare and ghosting, i.e. the ability of the binocular to suppress stray light and therefore preserve deep blacks. Macro-contrast is a good term for this overall contrast. Good macro-contrast is a consequence of high quality coatings, judicious use of stray-light baffles, the complex interaction of the geometry of the various optical elements, and to a lesser extent (in these days of good coatings), few glass-air surfaces.
"Resolution" is a poor indicator of performance, though measuring ultimate resolution at boosted magnifications seems to be a widely used testing method. But our perception of "sharpness" has very little to do with ultimate resolution (this is why we can see clear differences between binoculars that all have ultimate resolutions far beyond our eye's resolving limit).
Our perception of sharpness is instead based on a combination of
both resolution and localised contrast (or micro-contrast). It is much more important for a binocular to offer very high contrast transfer (as close to 100% as possible) at moderate spatial frequencies than very low (but just discernible with boosted magnification) contrast at resolutions far in excess of what the eye is capable of seeing. By testing for ultimate resolution we discover the highest frequency at which the binocular is capable of transferring some very low contrast value (perhaps 5 or 10%). This isn't completely useless because there is some correlation between high ultimate resolution and high contrast at low spatial frequencies. But it's quite possible for binocular A to achieve a higher resolution at 5% contrast than binocular B, yet for B to offer higher contrast at
useful resolutions (i.e. those visible without boosted magnification). In this case B will have higher perceived sharpness than A despite having lower ultimate resolution.
I used Photoshop to make a little example of this resolution-versus-contrast idea.
Click here to open two side-by-side images made from a single high-resolution photograph. Each image as presented is 512 pixels wide, but I resized the one on the left to a mere 256 pixels in Photoshop, then resized it back to 512 pixels, then applied a very aggressive unsharp mask (which increases localised contrast). The one on the right was resized from the original to 512 pixels (and no sharpening applied). This means the image on the right has approximately twice the resolution of the one on the left. Predictably, if you observe the photos closely, more detail reveals itself in the image on the right. However, if you walk back from your screen to a certain distance, perhaps about 2 metres (6 ft), the image on the
left will appear sharper! Despite its much lower resolution, its higher localised contrast gives it a higher sharpness. The image on the right, viewed from 2 metres, is like the image from binocular A, while the one on the left (at 2 metres) represents the view from binocular B.
The Nikon HG binoculars suffer from fairly severe chromatic aberration despite their generally good optical performance. Chromatic aberrations reduce micro-contrast by breaking white light from a point into its component wavelengths and spreading it over a wider area. For example, if you observe a power line from a sufficient distance for it to appear as a thin dark line against a white sky, any chromatic aberration will reduce the contrast of the line due to light from the sky being misdirected into the black area of the line, rendering it brighter (less black). If the line is thin enough you won't be able to observe false colour in it, but you will nevertheless notice a reduction in contrast (consequently causing the line to appear less sharp). A binocular with very low chromatic aberration will render the line blacker and more crisply.
I don't deny the Nikon HG L binoculars are a truly excellent value for money, but they certainly don't match the optical quality of the Zeiss Victory FL binoculars, which are probably the best roof-prism binoculars on the market by the sole criteria of optical performance.
). Thanks for a very interesting thread.
