On Wed, 8 Oct 2003, Bob S wrote: > Philosophically, Pentax went with small/light primes as an alternative to > zooms. I can still carry 2-3 primes for every zoom I might use, and get > better performance - Faster maximum apertures and sharper results.
Todays pro zooms are sharper than most primes, and faster than many old primes. They are BIG and HEAVY, though, and very expensive. You can get smaller, cheaper modern zooms but they are not faster or better than primes. Even the best zooms do have more distortion and other optical oddities than primes. Of course when the M lenses were introduced zooms were not as good as they are today. > The K 85/1.8 was preceeded > by the screwmount SMC 85/1.8, SMC 85/1.9, Super Takumar 85/1.9, etc. It > should be no big surprise that the 4th or 5th version of the lens was > optically great, even legendary. What might be considered surprising is that the M 85 f/2.0, which would be the 6th version, is often held to be much worse. It is much smaller, of course, than SMC/K 85 1.8. > But the K mount lenses are big and heavy. Relatively speaking. Ever play with any AF f/1.4 wide-angle? Of course the folks that buy such lenses don't mount them on MX-sized bodies! > At the same time, Pentax and the major manufactures were holding out for > optical quality. They wouldn't sell zoom lenses because the quality was > INFERIOR to their standards. Pentax made 3 screw-mount zooms, supposedly of very high optical quality. They are also apparently behemoths, so the argument that smaller primes were better than what it took to make a good zoom does still have merit. > Some people condemn the M85/2 as too soft, but it's a > fine portrait lens and I'll match it against your zoom in a poorly lit room > any day of the week. Not to condemn the M 85 f/2.0 (because the AIS Nikkor 85 f/2.0 isnt all that much better) but at f/2.8 most pro 80-200 zooms are sharper and with image stabilization almost as good in low light as an f/2.0 lens. Of course I'd much rather CARRY the M 85 f/2.0 than the zoom, and I could buy a WHOLE BAG of M lenses for the price of the zoom. Cheap 80-200/3.5-5.6 kinda lenses of course are a different story and the M lens beats them hands down. I've long suspected that the M 85 f/2.0 was designed as a portrait lens. More than any other manufacturer Pentax seems enamored of "soft" short teles optimized for portraiture, including 2 special soft-focus lenses and several lenses known to be soft wide open (SMC 120mm, SMC 85mm f/1.9, according to some the FA* 85mm f/1.4). I wonder if the M 85 f/2.0 is a reaction to the superb sharpness of the SMC/K 85 f/1.8 and a return to the portrait-friendly properties of the SMC 85 f/1.9? > And yes, there > some A* lenses that are extraordinary including the A*85/1.4 and A*135/1.8 - > real gems without any plastic. And lenses they never made in the M series > like the A200/2.8 or A100/2.8 Macro or A20/2.8... Or the A35-105/3.5 zoom, > a Pentax quality zoom. Or the A200/4 Macro. This is a longer list already than any list of "extraordinary" M lenses I've been offered. It might be argued that the A series is the high-water mark of Pentax optics. > After that, the great new lense designs get harder to find. The "pro" glass such as the FA* and FA limited come to mind, but certainly there are fewer great "run of the mill" designs in the autofocus era. > These lenses perform nearly identically to the K lenses they replaced. With > the M 120/2.8 and M150/3.5, you will be hard pressed to find a match in > today's lens line-up. But by all reports the K 150/4.0 was better than its M successor. That's what is really frustrating--supposedly great K designs such as the 28 3.5, 30 2.8, 85 1.8, 105 2.8, and 200 2.5 were replaced by supposedly inferior designs or simply discontinued. As you pointed out, the M to A changeover continued most of the better M designs, often with subtle improvements to glass or coating. I think the thing that gives the M series its feeling of being "lesser" is that some of the K greats had been lost and the A* greats had not yet been gained. The M series introduced few greats and a couple of relatively mediocre lenses. > The M20/4 makes the K20/4 look like a 135mm lens and > performs similarly. Same for the M28/2 vs K28/2. The original K's are > BIG, with no advantage in performance. >From what I've heard this is true, and is a good defense of the M series lenses. The M 50 f/1.4 and M 200 f/4.0 also are held to be as good as their predecessors as well as smaller. It's noticeable that the M 28/2 and 20/4 are very hard to find! > The M series are fine lenses, designed with a purpose in mind which they > achieved for the most part. True. Small and good is sometimes better than much larger and a bit better. The A* 200 f/2.8 is a superb lens with great handling that has given me some of my best sports action shots, but om vacation I'll take the M 200 f/4.0 every time. In twenty years of shooting an M 50 f/1.4 I've never had a hankering for a "better" 50. Your point that the M lenses have to be seen in historical context is also valid. Putting M lenses against modern pro zooms or FA asphericals is not quite fair. Compared to the primes and zooms of their day and the pro lenses of today the Ms are much smaller and for the most part competitive in quality. DJE
