In article , phardy@gol.com says...

>I know this is a simple question for most B&W users, but it's got
>me beat. I live some where hot and humid. I see relatively blue skys
>with indistinct white clouds. I'm a newcomer to B&W and get it
>processed commercially. My prints are coming back with no sky
>definition whatsoever: it's just white. The landscape is somewhat
>green, so I guess I should be using a green filter anyway, but I
>need to know why my skys are so bad first--I thought yellow and
>orange would be good starting points.
>My filters are 77mm, so I can't just go buy one of each colour and
>then experiment. I'd have no cash left for film :-)

I know the situation - we rarely see clear blue skies around here
either....! I think the film is being over-developed, since even
a white/overcast sky will usually be rendered as a very light grey
in a normal-contrast landscape print (the printer may also be using
a printing paper that is too high in contrast, but this is unlikely
with commercial printers, since it makes the job of getting correct
print exposure more difficult for them). I would not bother with any
of the yellow filters, since they will be VERY subtle in effect
under your sky conditions. The red filter will exaggerate sky detail,
but at the cost of three stops in film speed, and noticeable
darkening of landscape greens. The orange filter may be the best
compromise (2-stops loss). Be aware that camera TTL meters may not
meter color filters correctly (compare readings of a grey subject
with and without the filter and see if the correct difference
matches the metered difference - if not, add compensation to the
meter when using the filter [I add one stop exposure for Nikons,
which read through an orange filter as if it were a one-stop-loss
filter rather than two]). A very deep green filter can lighten
bright green folliage a bit, and darken a clear blue sky a bit,
but I would guess that it would not help under your conditions.
Hope This Helps