Primer: Planetary filters guide.

[GazOC 165]

Hi All,

I’ve been on my sickbed (well my sicksofa actually) the last couple of days bored stiff with only a laptop for company, so I’ve compiled this guide to planetary filters from various sites and Usenet etc.

I havn’t tested most of these – they are just random bits’n’pieces that I’ve dug up.

Light Yellow #8

83% transmission

False colour (purple fringe) elimination on Achros

Dawn/dusk terrestrial observing

Enhances lunar detail

Martian icecap/deserts

Darkens sky around Saturn and Jupiter

Viewing planets in daytime

Eliminates UV in B/W film

Medium Yellow #12

74% transmission

Lunar surface detail

Martian maria

Low contrast cloud detail on Venus

Definition on comet head and dust trials

Orange and red belt features on Saturn and Jupiter

Dark Yellow #15

67% transmission

Lunar surface detail

Martian icecaps/orange deserts

Low contrast detail on Venus/Mercury

Medium Green #56

53% transmission

Lunar surface detail

Melt lines on Martian icecaps

Contrast on red spot on Jupiter

Contrast all red/orange hues on all planets

Brighter comets

Venus cloud patterns

Light Green/Yellow #59A

79% transmission

False colour (purple fringe) elimination on Achros

Lunar surface detail

Martian icecaps and sand storms

Comet trails

Green Neutral Density #3N5

27% transmission

Best Moon filter for contrast

Venus cloud patterns

Martian icecaps

Lowers ‘twinkling’ near horizon

Violet Blue #47

13% transmission

Viewing Venus and Mercury in twilight

Best filter for Martian icecaps

Venus cloud patterns

Saturn ring definition

Dark Blue #38A

High contrast on Lunar detail

Brighter comets

Martian icecaps and high clouds

Viewing Venus and Mercury in twilight

Orange and purple belts and white ovals on Jupiter

Light Blue #82A

73% transmission

Pale orange and blue in Jupiter cloud belts

Comet trails

Suppresses false colour (green) in Achros

Orange #21

46% transmission

Lunar details

Martian icecaps/deserts

Red festoons on Jupiter

Orange bands on Saturn

Viewing planets in daytime

Neutralizes blue from Mylar solar filters

Sharpens daytime low light viewing

Light Red #23A

46% transmission

Lunar details

Martian icecaps/deserts

Red festoons on Jupiter

Orange bands on Saturn

Viewing planets in daytime

Neutralizes blue from Mylar solar filters

Sharpens daytime low light viewing

Red #25

Maintains night vision when viewing the moon

Details on Uranus and Neptune in larger scopes

Red plains and Maria on Mars

Darkens blue clouds on Jupiter and Saturn

Darkens background sky at twilight