This directory includes information about the Johnson RGO filter
which most of them were purchased in 1987.

The files info.jpg include some information about the purchase.

The files *.jpg are transmission curves of different filters.

The filters U, B, R, I-old, and Z, are the Johnson filters that were
purchased in 1987 and are now in a bad shape (U filter is useless)
with many flaws.

The V filter was purchased from RGO in 1994 instead of the old one
that was broken.

The I-new filter was purchased around 1996 and has a red cutoff which
the I-old filter does not have.

The Red-J-T filter was accepted from Arlin Crotts in 1995.