MTD 30MM THREADED YELLOW FILTER
Glass yellow filter with 30mm clear diameter. Mounting
is 38mm diameter with 36mm diameter threads. Has
threaded retaining ring to hold the filter in place.
M1603 $1.75
50MM DIA SHADE 5 DARK FILTER
These were made to be cut for eyeglasses for some fil-
ter application. Dark optical glass polished on both
sides. Master box indicates "shade 5". 50mm diame-
ter by 3mm thick. Might make a nice moon filter for 2"
eyepieces.One of our customers advises that these
"are replacement inserts for brazing (or welding) gog-
gles. They are used behind clear glass protective (and
replaceable) covers of the same diameter." Thanks Jerry
M2067 $0.50 or 10 for $4.00
RECTANGULAR GOLD CTD FILTER/BEAMSPLITTER
4.25" X 2" X 0.06" thick. Master box is marked
"GOLD/CR". Not sure what the original application was
but it acts almost like a beamsplitter. One side
reflects about 75% while transmitting about 25%. The
other side transmits about the same but with very lit-
tle reflection.. Looks like a fun piece to experiment
with.One of our customers was able to do an analysis of
its composition. Here's his findings: "180 Angstroms of gold deposited
over 30 angstroms of chromium on glass containing tin oxide"
M2068 $0.75 or 10 for $5.50
ND WINDOW, 4.3" X 2" X .3" THICK
Neutral density window. Optical glass, marked on the
side ND320. Not sure what the 320 refers to.
Appears to be medium density. Has arrow on side
pointing to one surface. Made by Perkin Elmer for
some precision specialty application.
M2083 $5.25
Page 52 - Filters
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