Originally posted by Damn Brit I'd be interested to know how many would actually buy this 400mm if it were to be released. That end of the market must be relatively small compared to shorter focal lengths. Pentax will only manufacture a lens they think will sell in sufficient numbers.
Hi Gary,
I normally shoot long (300mm or longer), so I would fit into the target market, and I wouldn't consider a DA*400/4. It would be bigger than my FA*300/2.8 (longer, with the same front element size --112mm), and that's about as large a lens as I can use practically (age and health considerations) on a daily basis.
Also, unlike many it seems, I don't have any fantasies about how much a lens of this spec would cost -- probably between $4.5-6K USD. After so much angst about the pricing of the K-7(???), I doubt that very many would actually part with over $4K for this lens.
Nikon and Canon not only have deeper pockets, but have guaranteed sales of these expensive lenses -- not only to the relatively large numbers of sports and wildlife Pros, but also to the very numerous world-wide camera gear rental houses. Pentax has to sell these lenses to individuals, and a relatively small segment of an already small market share at that.
I'd probably only get marginally better optical performance than I do with a 1.4x TC and the FA*300/2.8, so how practical would that really be? -- IMO not very. . .not for that kind of $$$.
A 400/5.6 or 400/5.0 would be much more likely choices, with a more practical size and correspondingly smaller price tag -- I might consider a 400/5, as it would probably still AF with TCs where an f5.6 might struggle, even with the increased AF sensitivity of the K-7.
. . . and speaking of TCs. . . but that's another post. . .
Bottom line, I think that Pentax's best bet would be to release a DA*300/2.8. They already have a superb optical formula, and would only need to add WR, SDM, and Quick Shift plus the digital coatings. This is a much more useful FL/max aperture spec for an ultra tele, IMO.
Scott