I have deliberately used the concept of publishable quality (PQ) to try to bring some common sense back into the IQ debate. I don't think magazines (who after all do most of the reviews) would have any problem at all deciding if images produced by a camera passed their own quality test for publication. Furthermore, we are the consumers of publishable quality images and I think we all have a pretty good idea if something is fit (quality wise) to appear in magzines and books or not. It is a much more meaningful concept than camera X exeeding the image quality of camera Y at 100% on a monitor. It relates IQ to practical use, instead of the theoretical 'top trumps' which camera manufacturers (and magazines I hasten to add) are very adept at using to make today's model appear obsolete by the end of the week.

Of course, camera reviewers would still be able to rave about how much a camera might exeed PQ, but buyers would know immediately that any PQ camera was suitable for their purposes up to a given size of image. It is also a measuring concept which does not age. PQ in 1998 is the same as PQ in 2008, so we would be able to assess the capability of old or new digital cameras much more evenly. Present methodology tends to cast as second or third rate those cameras which do not win the IQ test, yet they may be perfectly good and capable of PQ while offering other features which a buyer might prefer.

"Capable of publishable quality" is a concept used by Ivor Matanle in his Classic SLRs book . Lenses are graded using a 4 star rating, with 4 stars designating PQ. This tells us if a 1960s lens is fit for serious use today.

I agree that some of the 4/3rds lenses aren't that small but I think Olympus is addressing this. The second generation of standard kit lenses saw quite a reduction in size and I think we will see the potential for miniaturisation pressed home as time passes. At only 5 years old, the ZD lens system is still in it's infancy. The advantage is indeed more apparent with longer lenses.

Yes, I very much agree about the desirability of IS in a 4xx body. It would be a very attractive camera. Let's hope it comes next time around.