philbarton
Senior Member
==============About the price of in-body/in-lens stabilisation system, I think it
is about the same. It is same if we consider that users keep lenses
longer than bodies. So, for the first kit, the cost is higher, but it
will be amortize when people changes the body.
That's a sensible way to look at the economics. The buy-in per-lens is a bit higher; but since the majors all depend on IS in lenses, the choice is simply having IS; or not having it - but on a per-lens basis. There's less need on a wide-angle, for example. The basis of Pentax' IS was really to allow a slower shutter speed when a bump in ISO was not desirable - but someone shooting a wide angle in daylight should not have the problem to the same degree as shooting a tele.
With a higher-magnification tele, in-lens IS allows for a stabilized image when viewing, which is more comfortable to deal with, and keeps a spot-meter reading on the desired AF point. If the subject moves laterally, you can pan and switch off horizontal stabization right on the lens, while maintaining vertical stability.
There would be less repair cost on a body without either internal-IS, or a screw-drive supporting the AF. Let the lens do both. The body-maker then does not have to design the next model around those 2 functions; and be concerned with maintaining legacy functionality (as Pentax had to with the latest lens series), which annoyed the 6 MP'ers still using those bodies.
The micro/hybrids point up the benefit of eliminating the mirror box, and the attendant mechanicals and weight - and Panasonic G1, in reviews, is being praised for an improved contrast-detect - which will get more out of an f/4.0 lens.
Your main point about the longevity of lenses is important - because there are now rapid technological gains coming in bodies; whereas lenses out there are already of high caliber, including modern optics. This allows a (C) or (N) owner to have, say, a FF body, or a body with movie mode - plus a very inexpensive backup in the form of the XS, as one example. The FF lenses will operate on APS-C; but won't perform as well in some cases as a lens with the appropriate image circle. When lens-makers run out of features to add (and compete with), the price should drop. What's needed is sales volume, and whatever the lens, more 3rd-party can be sold in (N) or (C) mount than anything else; since the OEM lenses tend to be expensive.
Anyone serious about fast-AF in a zoom should seriously check out the f/2.8's; and those are stabilized these days, with ring-USM or the equivalent. Pentax does not have the user base to support marketing those lens equivalents, and is charging about $1500 for the new f/4.0 zoom.