My experience is opposite
Bought just one 16-35 2.8II & 24-70 2.8, both made in 2008 and they're fine copies. Nice thing with canon is they date code lenses so I can tell if my new glass is newly made or older stock. Everything I got new is Dec 2007 thru Dec 2008 manufacture and I have no complaints. Just glad I bought them all before the price increases.
As far as pentax goes I suspect over the years people will rightly covet "Japan" made Pentax glass & it will sell for more money on used market. All my Pentax glass is Made in Japan except a 80-320 FA I bought new a few years ago. Surprisingly back then it was boldly marked VietNam, not hidden inside the mount like Pentax does thesedays. No complaints with the 4 to 1 FA zoom either. All the old FA and SMC-A glass I have keeps me owning one Pentax Dslr.
If I had to buy new Pentax lenses I would only consider Made in Japan origin. I don't think this is possible now as I think no pentax lenses are Made in Japan now. Pentax "Made in Japan" Quality Control is worth the extra shopping effort. At least to my wallet it is. As it is I am no longer adding to my Pentax kit at current market prices for new or used.
Anyways, to me, you seem proud to own a 31mmLTD Made in Japan as its:
"100% Japanese"
You should be proud of your 31mm LTD as the Hoya lenses will never be Made in Japan again. Those days are over.
Originally posted by Digitalis well my FA31 is 100% Japanese, I bought it on 27th march 2009 and considering the serial number, it's probably one of the last of the Japanese stock. And it looks like I got mine in the nick of time, I only paid $1450 Aud for mine.
Geography has little to do with image quality, the FA31 is indeed a phenomenal lens..all this means is that it may take some looking around to find a good one. the lens design is excellent it doesn't matter one bit as to where it was assembled, as long as the QC keeps it's eye open. Pentax isn't alone in this regard... I went through 5 copies of the Canon 24-70mm f/2.8L to find one that performed evenly at the wide end at Max aperture. I had a similar issue when I upgraded to the 16-35 f/2.8L MKII lens (I went through 3 copies some of them were de-centred). And my Canon 24-105mm f4L IS was one of the early ones that suffered from a rather horrendous flare problem....there is no rest for the wicked.