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Possibly stupid: Where does a moon filter go on a telescope?
Yeah, I know, I feel like an idiot for asking, but I can't seem to figure out the answer. I've got a plain old 4.5" reflector telescope, which is about 10 years older than me but exactly the same as the fancy one my parents just bought, and I want to get a moon filter for it, but I seem to be too stupid to figure out what size I need. Are there two different kinds, one that goes on the front end (so I guess would be 4.5" diameter) and one that goes on the eyepiece (roughly 1.25" diameter)? I just don't know what I'm looking for. I'm a long time astronomy hobby-ist, but haven't done hardly any playing with telescopes, other than setting up the computer on my parents'. (Mine has no computer, that's the only difference). Anyway, some help would be highly appreciated.
3 Answers
- GeoffGLv 710 years agoFavorite Answer
A Moon filter screws into the back of the eyepiece, normally 1.25" in diameter.
Normally I don't recommend buying a Moon filter, because most of them are of poor quality optically and are, in any case, unnecessary. Although the Moon may seem bright in a telescope, it really isn't any brighter than sunlight on an asphalt road. It only seems bright because you're looking at an object in full sunlight in a dark sky from a dark location. I always observe the Moon without a filter, as I prefer the unfiltered view, even with my 11-inch telescope. Your eye will adapt to the brightness in a second or two -- you can also dim the image by going to a higher magnification. The Moon can handle almost any magnification you throw at it!
Source(s): 54 years observing the Moon. - Anonymous10 years ago
Look at the interior of the open end of an objective lens, See the screws? That's where lunar and solar filters screw into the eyepiece. IF your telescope came with a solar filter like mine did, don't trust it. My solar filter cracked, quite loudly, after sizzling for more than minute. Fortunately when my Dad was NOT looking through the eyepiece. Purchase a solar filter that will fit your eyepieces that have a warranty or guarantee. There are dozens of advertisement in Sky and Telescope and Astronomy magazine from companies who know how to make good solar filters.
