In article <30e464f4.3215089@nntp.ix.netcom.com>, obryk@ix.netcom.com says...(virtually all of a nice post [agreeing with mine ;-] deleted)
>5) IMHO the best all-around filter is a Wratten #8, also known
>as K2 or medium yellow.

In the West, or at high altitudes, where the air is clear, and the
sky can be a deep blue, I would agree with the above - but in the
murky Eastern US, it is a waste of film speed (you will not see the
difference with, or without it). It takes an orange to begin to
show much of a difference, unless the day is unusually clear. I
always have a good laugh when I see the samples in photo books supposedly showing the differences between no filter and a medium yellow. If you go out on a reasonably clear day where I live with a stack of filters, shoot an average scene with the sun to your side
or back, and include sky, clouds, grass, trees, buildings, etc., and
a grey card for reference, and do it with no filter, then with each filter in turn (adjusting the exposure with the filter factor and not the camera meter, and using the grey card in the photos as a
reference [it should be the same tone in all the photos]), you will
be amazed at how subtle (or lacking) the changes caused by using the filters will be (try making a contact print of the negatives to
reduce printing variations). I have a mint collection of Nikkor
filters consisting of 2 ea. 52mm, 1 ea. 62mm and 72mm in dark
yellow, orange, red, and medium green. They sit in the box - anyone
who believes filters (other than orange and red) make a difference interested? :-)
Hope This Helps