Filter No

Description

Typical use

ND25

25% transmission neutral-density

For attenuating image brightness when viewing bright targets such as the Moon. Clarifies separation of double stars. Not included in 2” set

ND13

13% transmission neutral-density

For further attenuating image brightness when viewing bright targets such as the Moon. Clarifies separation of double stars.

#11

Yellow/Green

Useful for reducing chromatic aberration seen in achromatic refractors, and for glare reduction while observing the Moon.

#12

Yellow

Glare reduction and contrast enhancement.

#21

Orange

Increases contrast and surface detail on Mars and enhances cloud band detail on Saturn. Also corrects the image of the Sun to a more natural appearance when using a Mylar solar filter.

#15

Yellow/Orange

Useful for enhancing cloud bands on Saturn and Jupiter.

#23A

Light Red

Darkens sky while viewing Venus and Mercury. Increases contrast and surface detail on Mars (stronger effect than #21).

#56

Green

Increases contrast and clarity of red detail in Jupiter’s cloud belts and great red spot. Can be effective in enhancing cloud belts of Saturn and enhancing detail around the polar caps of Mars.

#80A

Medium Blue

Enhances cloud formations on Mars, and makes white ovals in Jupiter’s cloud belts easier to see.