From garyr@as.arizona.edu Fri Sep 30 15:09 MST 1994
Date: Fri, 30 Sep 1994 15:13:03
From: garyr@as.arizona.edu (Gary Rosenbaum)
To: lesser@astro.as.arizona.edu
Subject: 90" filters

You know about the Harris filters, the 4" I band filter and the new HST 
filters. These are all in excellent condition except for the few small 
internal spots that were present when new.

2x2" Nearly Mould Interference filters in 2" holders;
U 365nm has ~20 very small spots inside
B 442   has a couple of scratches ~ 1/4" in from edge
V 548   good condition
R 646   no scratches but some internal spots
I 829   no scratches but shows internal streaked structure. I think you were 
already aware of this. It is not new.


In wood box labeled Quartz Netural Density Filters
All in 2" holders.
50.5%  old
23.8%  old
10.2%  old
9.6%   old
5.6%   old  these first five old filters are badly scratched
2.6%   slot in box for this filter but no filter present
0.9%   old  good condition
0.7%   old  scratched

5004 R  in good condition
Corning 1-64 Enhance Blue & UV  4501  size is ~1/2x1/2" square  is in good 
condition except for small chip at very edge  has a round aperture stop 
~1/2" diameter

50.1%  new
39.8%  new
31.6%  new  these first three new ND filters are in good condition
10.0%  slot in box for this filter but no filter present
1.0%   new scratched

In cardboard boxes.
(quantity 1) Crystalline CuSO4 Filter #1  ~1/2" diameter in square plastic 
holder

(quantity 3)  LB-120  50x50mm square  2.5mm thick Hoya Optics not in holders
(quantity 2)  LB-60   50x50mm square  2.5mm thick Hoya Optics not in holders