I read an article about Leica optics and was impressed about how little optical tolerance variation they allow. There was a comparison with Minolta and it seems that Leitz lenses are twice as tight on acceptable variation. I have heard similar things about Zeiss. Even though the glass types used between companies are nearly identical, and the designs are similar, the acceptable variability during manufacture can be quite different. The inconsistancies in the Pentax line of lenses may be due to this acceptance of high variability by Asahi Optical. There are several reports of people selling lenses because they were soft, and upon buying the same focal length lens later on, finding that lens to be much sharper. I buy the older, lower production lenses with no fear but am cautious when considering newer lenses.

-- Steve Rasmussen (srasmuss@flash.net), May 07, 2001

Answers

Mark, there are many aspects of quality in lenses. Design, process control during manufacturing and the precision of assembly are all critical. Asahi has some great designs but translating those to a finished lens is to what I was referring. Sometimes when a company moves from small production to higher production, the manufacturing processes degrade. I feel the 105mm has had problems in this area. Pentax sells many more 67s than it used to. There were so few users 15 years ago that a forum like this would not have been possible, even if the internet existed.

-- Steve Rasmussen (srasmuss@flash.net), May 27, 2001.

I've heard the same thing, but I must say that, within the last year, I've purchaed current 55mm, 90mm, and 165mm LS lenses for my 67II, and have found them all to be wonderfully sharp.

That said, subject matter, composition, and lighting still seem to be 99% of the deal with any decent lens.

Tom

-- Tom Tretheway (tomt@ncal.verio.com), May 11, 2001.

Everything I've heard suggests that the very newest Pentax 67 lenses are higher in quality than the older varieties. My single sample of the current 90mm is great, but it's only one lens, so it doesn't mean much by itself.

-- Mark Wilkins (mark_wilkins@yahoo.com), May 27, 2001.