Most used depends on the tides but would have to include:
FA 43mm
FA 77mm
K 50mm f/1.2
Vivitar Series 1 105mm macro
DA 12-24mm
Vivitar 24mm f/2 CF
Vivitar 28mm f/2 CF
Vivitar 135mm CF

Least used would be the four or five other 28mm lenses I have, a Sigma 70-300 zoom, the kit lens, etc.

My least used good lens that I would not sell is the DA 55-300mm since I rarely have a need for telephoto.

Late to the thread, but I would say f/2 is essential almost all the time. And not just for black cats in coal cellars. Today is a nice bright day (for Ireland) and I just metered my black cat in the living room (lots of diffuse light). I need f/2 at ISO800 to have a hope of freezing even small movements, though really I need to go to 1600 or higher. For me, any lens slower than f/2 is rather lame. (Though I make an exception for certain zooms, not that I use them much.)

I have two f/1.2 lenses and would only shoot wide open for special effect, given how strong the aberrations are. I don't find it that appealing and can get much nicer effects in PP.

K10D, I don't get your point and assume you are misreading mine.

But read the Leica literature and they actually discuss the weaknesses of different lenses and the compromises of using the cheaper ones compared to the more expensive and (we assume) better designed. It's terribly refreshing!

Comparing across systems is even more impossible than comparing across sensors in the same system.

To be clear the FA 50/2.8 macro is likely the sharpest Pentax lens from f/2.8 to f/4 (according to Yoshihiko), equalled at f/5.6 by the FA43. Of all the lenses tested for the K10D by Photozone the FA43 is tops. But there's little point in arguing a few points one way or another when so many other factors are equally if not more important.

I for one do not dispute the test findings in general, which seem quite in accordance with previous tests and images from the lenses. It is only the rather odd finding of exceedingly low MTF50 in the corners of the FA43 that seems out of kilter. I would not expect this to be so bad when stopped down.

MTF tests are very useful, especially those Leica and others publish, which show sagittal and meridonial measurements. The relationship between these can even predict how pleasing the bokeh might be. If all manufacturers were as open in providing these, it would be great aid to intelligent buying decisions.

APS-C is good enough for many people all the time, and even more people most of the time. Some will be convinced to chase ever-better specs regardless of what they see in the finished images. This has nothing to do with photography and everything to do with marketing and techno-fetishism. I am sure the manufacturers are salivating at the chance to convince all of us we need to ditch our systems and buy more expensive ones.

(Though the marketing lately seems to be towards photographically inferior systems that have a certain retro cache, gadget fascination and hyped price points.)

Those that really do need the extra quality are already using medium format.

Just like those who need the best from APS-C are already using Voigtlander, Zeiss and FA Limiteds.

Yep, better to have larger sensors than cram in extra pixels into the smaller sensors. Just ask the Nikon D700. This has many benefits including lower noise and smaller apertures before diffraction becomes a problem. A discounted version of the 645D with fewer pixels would in many ways be a better camera.

I have written about this a fair amount on my blog recently, as I've been exploring the MFT format.

Is that just from a comment Ned made on his blog? Or is there another source?

In any case your own tests demonstrate this is not true. The FA77 out-performs the DA70, the FA31 has better figures than the DA35 and the FA43 (despite some odd numbers) has peak sharpness better than any tested lens. Putting aside raw numbers (as photographers should) these lenses produce images with pleasing and distinctive rendering that can be used, by those who learn their attributes, to produce superlative photos.

It is evident that Pentax has lost the will to make lenses of this quality, but thank goodness they had Jun Hirakawa when they did! (Maybe Ricoh will hire him back.)

Now that is an image that shows the FA43 look. Here's another from a while back.


[IMG]http://farm4.static.flickr.com/3163/2451978963_8804e9276f_o.jpg[/IMG]