Brock - You probably have done more studying and research into the SE coatings than anyone who uses this site. So my question is directed to your understanding of Eco-glass vis-a-vis the older lead based glass. I thought that prisms with lead had an inherent advantage in reducing aberrations. Am I mistaken? When did Nikon incorporate Eco-glass with the SE 10x35, which I find to be a remarkable binocular - better than any other 10 power I have examined?
John
John,
This brings up an old (and controversial) topic of lead vs. lead-free glass. When manufacturers introduced lead-free glass around 1999-2000, reports of increased chromatic aberration in roofs with lead-free glass ran rampant.
Also, I read two reports from OHARA, which I posted on BF, that said the company took a trial and error approach to find which combination of lead substitutes were good enough and yet cheap enough to make lead-free glass that was suitable for sports optics and microscopy. At the time of the report, 1999, OHARA's lead-free glass, according to the author, was improved but still not quite on par with their best lead optical glass. The other report showed that their lead-free glass showed more CA at the extreme ends of the spectrum than their lead glass and was therefore not as good as lead glass for microscopists, who use high magnifications in their work.
In addition, comparing the Nikon HG to the HGL, the latter version with lead-free glass produced an inferior image to the original, IMO. Greater CA and the color representation was not as "true" as the originals with lead glass. The image also "washed out" when looking at brightly lit objects.
These three things lead (no pun intended) me to conclude that glass manufacturers, or at least OHARA, had jumped the gun and released lead-free glass that was not up to the standard of lead optical glass, and I extolled the virtues of lead-free glass. Some still believe it is superior to lead-free.
Since then, Henry and others have come up with an alternate theory about why roofs at that time showed an increase in CA - the introduction of internal focus and the focusing element. Hence why ED/HD/FL glass has become all the rage in roofs today.
I think you meant to write 10x35 EII, and I agree, it's my favorite 10x bin too. The EII's employed lead-free glass from the outset, which was 1999. The SE, however, remained with lead glass for a few more years, not sure why, but it only in the past four or five years did Nikon start advertising the SE as having "Eco-Glass."
Nikon made a big stink about the EII's having Eco-Glass, as mooreorless pointed out when he shared what they wrote in their 2000 catalog about the EII"s environmentally friendly glass, so it makes no sense, if they had switched to Eco-Glass in the SE at the same time as the EII, why they would have held off for six years before mentioning that in their ads and catalogs.
In any case, the 8x32 SE 550xxx and the 10x42 SE 050xxx are advertised as having Eco-Glass, and the view is superb. Less CA than the 505xxx 8x32 SE I had, which presumably had lead glass, more like my early lead glass 501xxx 8x32 SE, but brighter and with more contrast.
Coatings are supposed to be matched to the type of glass used, so presumably, Nikon changed the coatings when they changed over to Eco-Glass, and the results are stunning. Best view I've seen through binoculars. When you consider the price, it's even more remarkable.
Brock