Thousand Oaks H-Alpha Prominence Filter (1.5 Å Bandwidth)
Fits Questar and Meade ETX-90 Maksutov designs. Mint Condition. Only
used about a dozen times. Sale price = $495.
This two-part 1.5 Å bandwidth solar prominence filter is easy to use
and can be set up in less than a minute. It includes an energy
rejection filter (ERF) and H-Alpha filter unit (H-A) with a tilting
The ERF fits over the front of the telescope tube. This particular
ERF is mounted within an aluminum cell with padding on the inside
edge for a snug fit. Although the off-axis ERF included in this
package fits Questar and Meade ETX-90 Maksutov designs, the inside
diameter of the cell can be made to fit telescopes whose outside
diameter ranges between 4 and 4.25 inches by removing or adding
additional padding (not included). For telescopes other than the
Questar and ETX-90, ERF's can be purchased separately from Thousand
The H-Alpha filter unit (1.5 Å Bandwidth) is a compact
4 3/4" long x 2" diameter and weighs approximately 7 oz. It attaches
between telescope back and star diagonal or between star diagonal and
eyepiece and accepts standard 1 1/4" accessories. The filter has a
tuning mechanism which allows you to optimize transmission and
contrast for the particular features you are examining. No heating
or electric power is required as is with some other types of H-Alpha
The original retail price paid for this two-piece solar prominence
filter was $729. I am offering the complete package in "like new"
condition for only $495. I'm prepared to ship immediately upon
receiving your money order or cashier's check. Personal checks can
be accepted, but I'll have to hold shipment until it clears. Checks
and money orders must be drawn on US funds. I'll pay regular shipping
costs within the United States. Expedited delivery is extra.
Thanks for your interest.