I'll respond to a few of the other messages in this thread. (Sorry
if this is a bit long of an answer - remember, though, I could have
"flooded" the thread with a bunch of short answers instead - <g>.)
Was the 200/2.5 easier - faster to work with than the 80-200/2.8
at the long end, or no significant difference?
I can compare the K 200/2.5 to the manual focus Tokina AT-X
80-200/2.8 (which I still have) and to the A* 200/2.8 (which I no
longer have). I'd say the ease of focusing is essentially the same
in all three. I'd say that the focusing feel is slightly "stiffer"
(although still very smooth) in the 200/2.5 than in the others
(while the A* 200/2.8 has the "easiest-to-turn" focus feel).
I did own the K 200/2.5 and the A* 200/2.8 both at the same time for
a while. I actually had the A* first, and picked up the K lens
later. I liked the K so much that I ended up selling the A*. (Go
figure...)
Actually, the K 200/2.5 and the K 135/2.5 are my two most favorite
K-era Pentax lenses (not including a few dear VS1 lenses of that era
that I also love). That's not too surprising, I guess, inasmuch as
the K 200/2.5 and the K 135/2.5 share the same optical design as the
premium A* 200/2.8 (and these are the only three Pentax lenses to
share this particular design, I believe). (It's not just the "6
elements in 6 groups" configuration that they share - their optical
diagrams are also virtually identical.) (The K 200/4, in contrast,
also has a "6/6" formula, but a different optical diagram.) See:
http://www.bdimitrov.de/kmp/lenses/primes/_optics/135f2.5-i.gif
http://www.bdimitrov.de/kmp/lenses/primes/_optics/200f2.5.gif
http://www.bdimitrov.de/kmp/lenses/primes/_optics/200f2.8-i.gif
(The A* lens, probably due to its use of LD glass, has just a ~very~
slightly different shape to some of the elements, but the two K
lenses are virtually identical.)
Sure it's fast, as fast as you can turn the large grippy focus
ring.
...which is a real pleasure, if you're a manual focus fan. Objects
really seem to "snap" into focus at 200mm and at f/2.5.
There is no perceptible difference in light level between a 2.5
and a 2.8 IMO.
Agreed. An f/2.5 lens is supposed to be faster than an f/2.8 one,
but it's not a big difference. And, I'm just a bit dubious about
the "f/2.5" in the K 200/2.5, anyway - with a 77mm front filter
mount (and with a clear aperture of therefore a little less than
77mm), it seems to me (who admittedly doesn't know much about
optics) that 200mm divided by 2.5 should require a clear aperture of
80mm.
The A* 200/2.8 also uses 77mm filters, but the actual diameter of
the 200/2.5's front element is definitely a little wider than that
of the 200/2.8's front element - i.e., the circular "frame" around
the outer edge of the 2.8's front element is definitely more
restrictive than is the thinner "frame" on the 2.5. Still, 200mm
divided by 2.8 is only 71mm, while 200mm divided by 2.5 is 80mm.
The fastest 200 you can buy in K mount.
If it really is a true f/2.5 lens, then that would be true. When
the lens was first introduced, the Pentax Lenses and Accessories
booklets of the time stated: "In testimony of its role as a leader
in the field of optics, and ever mindful of the needs of the
professional photographer, Asahi Optical has introduced the first
200 lens with an f/2.5 maximum aperture. This ultra high-speed
telephoto lens is well suited for available light photography, such
as indoor and nighttime sporting events. Even when used wide-open,
its 6-element, 6-group optical design ensures high contrast and
resolution, as well as attractive out-of-focus highlights." And
that's an "objective opinion" (no pun intended) - <g>, but, it's
true - sharpness, contrast, and good bokeh are definitely
characteristics of this lens.
No tripod collar is a big minus (IMO).
True. (I do think someone here on PDML tried out one of those
custom tripod mounts - from a UK company, if I remember correctly -
for this lens some time ago.)
I am big of frame and sturdy of leg (!) and heavy gizmos don't
phase me but I wouldn't like to hand-hold that monster much under
1/250th. No tripod mount means you're on your own there.
Mounted to a body that is mounted through its base to a tripod, the
lens is extremely front heavy (and probably would strain the frame
of the body if it's at all "plasticky" - most of the metal-bodied
camera bodies would handle the load OK, however).
The lens really works well with a monopod (especially for low-light
use, which is where it really shines). With one hand cradling the
focus ring on the lens, and the other handling the body, the
font-heaviness of tripod use seems to disappear (with monopod use).
Fantastic build, very smooth. Very sharp.
True, true, and true. I'd say its optical performance is
essentially identical to that of the A* 200/2.8 (despite the
latter's LD elements). Theoretically, I should see just a slight
sharpening of edge detail with the LD A* lens, but I never could
notice a difference (although I never blew up any images to monster
size, either...).
I have to say that the K 200/2.5 is a ~pretty~ lens, too - it has
the ~prettiest~ SMC coating to look at (if one is partial to the
color blue, as I admit to be - <g> - in contrast, the A* 200/2.8 has
a rather greenish SMC cast.
The hood is big enough to bivouac two in an emergency and the case
has tandem axles and full electrics.
HAR!
I love the K 200/2.5. I'd recommend the lens to anybody who wants a
sweet and fast 200mm manual focus lens (and who doesn't mind the
weight).
Fred
