Use the filter that has a color "opposite" to the color of the feature you want to examine. For example, a red/orange/pinkish feature, such as the GRS, may best be seen using a mild blue filter. Same with Mars. Using the "opposite" color will increase the contrast of the detail with respect to it's surroundings. A red filter sometimes makes bluish festoons stand out better. I'd say I use my medium and light blue filters the most. BTW, a broadband LPR filter can increase contrast on Jupiter noticeably. Sometimes a violet filter will enhance cloud features on Mars, especially near the limb, by supressing the overall reddish cast of the planet. Without recalling the Wratten numbers off the top of my head, I'd suggest getting a medium blue, medium red, medium yellow or yellow-green as one's first filters. A dark violet or ND "moon" filter works wonders on Venus, where the brightness is so overwhelming it can be hard to even see the phase easily. Chuck --- Richard Tenney <retenney@yahoo.com> wrote:
I would be interested (as a person not owning any filters yet) in knowing what the experienced planetary observers on the list recommend as far as color filters go for planetary viewing; what color(s) seem to work best for Jupiter? How about the other planets? -Rich
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