Burgess Optical Colour Filter Set

Burgess Optical is now offering color filters. These filters are Hoya filters and are available in
12 different colors. The Hoya filters are glass and mono-coated (single anti-reflective coating).
The filters fit standard 1-1/4" threads. Each filter is threaded to accept another filter or other
threaded 1-1/4" accessory. Fully screwed into an eyepiece or diagonal, each filter protrudes
an additional 5/16" (7.2mm) beyond the end of the barrel.

Each filter comes in a plastic case. Each case is 1-7/8" x 2-3/4" x 3/4" (48mm x 68mm x
19mm) and comes with a friction fit cover having a clear window.

Each filter has our name opposite the number of the filter. The common color name of the filer
is printed on the back of each plastic box. To easily determine the color of a filter when
observing after dark (tip not needed for solar observing!), hold the filter up to your eye while
looking at a bright white star. The star will be the color of the filter. If you are not observing at
a dark site, just put the filter between your eye and one of your neighbor's lights.

Each color is useful for bringing out planetary detail.
See http://sciastro.net/portia/advice/filters.htm for a good description of filters and what each
color is best suited for. The following list identifies each of the filters by Wratten number and
color.

Number: Color
8 Light Yellow
11 Yellow/Green
12 Yellow
21 Orange
23A Light Red
25A Red
38A Dark Blue
47 Violet
56 Green
58 Dark Green
80A Medium Blue
82A Light Blue

The Filters are available individually or as a full set of 12.

Prices:
Individual Filters - £10.00
Full Set of 12 Filters - £95.00
Filter Case (holds 4 filters) - £3.00

The Astronomy Shop

1 Tone Hill. Wellington

Somerset TA21 0AU

United Kingdom

Telephone: +44 (0)1823 665510