P.S. to Patrick - I have posted the first message to this list twice.  Please use some of your god-like moderator powers and kill the first copy. Thanks - Kurt To the group as a whole - in anticipation of follow-up questions on filters and stopping down your aperature, I have pre-posted my general response to that question. - Clear Skies - Kurt -------------------------------------------------- S - To observe visually, no filters will be needed. Use at least 5 inches of aperature, 10 inches or more is perferred. Use the highest feasible lunar planetary imaging power that your scope will handle - 300x is what I am using based on test observing and imaging for the last month. At such high magnifications, lunar glare will not present a problem. There will be no glare and so accessory actions like stopping down your aperature or using filters to reduce the brightness of the image are not warranted. David Knisley's useful magnifications list is generally used by amateurs for magnification guidance. Knisley's recommended maximum magnification for "specific lunar and planetary detail" visual observing is: Low Mag Per Inch of Aperature: 30.0  High Mag Per Inch of Aperature: 41.9  Low Exit Pupil mm: 0.7  High Exit Pupil mm: 0.6  Useful Mag Description: Very high Used For: Specific planetary lunar detail For a 10" aperature scope, the maximum recommended magnification range is 300 to 410 power. Such filters or other glare reduction procedures may reduce you chances of seeing the plume by reducing the peak plume brightness that your scope can capture. There is a recommendation on the LCROSS Citizen Science "About" page to use a polarizing filter. I have no comment or feelings about that recommendation. http://apps.nasa.gov/lcross/about/ The above is, of course, IMHO. Clear Skies - Kurt P.S. - The LCROSS Team Citizen Science About page recommendation reads: "However, observations are not trivial as the dust cloud may have a brightly lit Moon surface behind it, depending on the exact impact site selected, making it more difficult to see the dust cloud due to the poor contrast; bright dust against a bright Moon surface. The dust will polarize the scattered light but using polarimetery can help with the observation."