Which filter in the Celestron Set is best for observing Jupiter's Great Red Spot?
The #80A Blue filter is the most effective choice in this set for enhancing the visibility of Jupiter's Great Red Spot. It increases the contrast between the reddish storm system and the surrounding lighter cloud zones.
How do I attach a filter from the Celestron Lunar and Planetary Filter Set to my eyepiece?
All filters in this set are designed for 1.25" eyepieces. Simply screw the filter into the threads on the bottom barrel of your eyepiece. You can then insert the eyepiece into your telescope's focuser as usual.
Can I use the #12 Deep Yellow filter from this set on Mars with a 3" refractor?
Yes, the #12 Deep Yellow is an excellent choice for smaller aperture telescopes (less than 4.5"), making it a good match for a 3" refractor. It will help bring out details in the Martian polar ice caps and any potential cloud formations.
What does "stacking" filters mean with the Celestron 1.25" Filter Set?
Because each filter cell is double-threaded, you can screw one filter directly onto another. This allows you to combine their properties. For instance, stacking the ND-96-0.3 filter with the #21 Orange filter would reduce Mars's overall brightness while still sharpening surface details, which can be useful in larger telescopes.
Why is a Neutral Density filter included in the Celestron Planetary Filter Set?
The ND-96-0.3 Neutral Density filter is primarily for lunar observation. A full or quarter Moon can be overwhelmingly bright, causing eye strain and hiding detail. The ND filter dims the view to a more comfortable level. It is also useful for splitting unequal binary stars, where the glare from the brighter star can hide its companion.
Will these filters work with a 2" eyepiece?
No, this Celestron filter set is specifically designed with 1.25" filter threads and will only attach to 1.25" eyepieces and accessories. They are not large enough to be used with 2" eyepieces.