Yellow (#12) is useful for observing Mars, especially to highlight light areas or darken blue or brown features.
When observing Jupiter, #12 is used to darken blue festoons near the equatorial regions.
When used to observe Uranus or Neptune, it enhances the blues and greens of the atmosphere.
1.25" Vernonscope Mounted Glass Filters feature 1" clear-aperture optical glass. Numbers are engraved on the mounting to correspond with those of Kodak Wratten series. The mountings are edge-knurled and threaded to fit the bases of BRANDON oculars and DAKIN Barlows. Vernonscope Mounted Glass Filters cut glare, provide superior contrast, improve definition and reduce eye fatigue.