In article <4hmj6d$t3g@nntp.hut.fi>, kelorant@hila.hut.fi says...

>Recently I had an opportunity to shoot a few dozen rolls of slides,
>all with same equipment and under similar conditions, outdoors.
>Some Fuji (mostly Velvia) and I knew that it would come out different
>from Kodachromes, but what surprised me was that there was such a
>striking difference between the latter.
>Why is it so that Kodachrome 200 seems different from the slower
>Kodachromes, 25 & 64? I shot them at the rated speeds, but bracketed
>quite a bit, so I felt I had to be getting properly exposed frames
>in most situations. But at the end it was so obvious, which ones were
>taken with KL200: apart from the slightly bigger grain they had more
>exposure latitude and more vibrant colors. Not exaggerated though I
>felt, and it was really nice for portraits. In comparison the slower
>ones looked quite flat and downright worthless for e.g. portraits
>(and clearly inferior to Velvia for landscapes). KR64 & KM25 seemed
>to wash out the sky/higlights extremely easily whereas KL200 seemed
>to able to keep it alive and find some nuances. Does anyone know if
>KL indeed can take a couple of more stops of contrast than the others?
>So I'm just curious, is KL200 fundamentally different emulsion? Anyone
>care to comment/tell your experiences.

Well, yes. each Kodachrome is a different film, with its own characteristics. I prefer K200 to the other Kodachromes for
aerial work, evening and grey-day shooting, stage shooting, etc.,
and really like it except in sunny situations, where its contrast
is too high for me. I have slides shot on K25 and K64 that have
wonderful color, but it seems harder and harder to get good results
with the slower Kodachromes (blue skies are often weak and greenish
or pink [the film base is pink, and as greenish high tones approach
white, the color of the high tones shift toward pink - especially
noticeable in photos of skies and waterfalls], and the greens are disappointingly bland), so I have switched to Fuji 50 for much of
my work, with Velvia (actually about 40), Fuji 100, Sensia 100,
and Kodak Elite 100 and "400" (actually 320), filling in for
my remaining needs.
Hope This Helps