Is a 10mm or 5mm lens stronger in a telescope?
Saturday, December 11th, 2010 at
9:42 pm
I bought a telescope and want to use it.. but it doesn't say whether when I use the 10mm lens if it is stronger or if I use a 5mm lens. Thanks for your help in advance!
thanks.. i just wanted to know the generals not the actually magnification.. and apologies on the lens/ eyepiece word use.. not a pro yet. lol


US $18.99



The 5 mm will give you a greater magnification (it will make things look bigger), but it will make the image appear dimmer and it will make it a lot harder to find stuff (because it will give you the narrower “field of view”).
We use the lower magnification to find the object and centre it, then we move to the higher magnification.
However, the resolution will not be improved. The ability to distinguish details is given by the size of the main lens or mirror.
First of all, they’re called “eyepieces,” not “lenses.” The shorter their focal length, the greater their magnification. So your 5mm eyepiece will give you twice the magnification that the 10mm eyepiece will give. You haven’t told us the important specifications of your telescope (its aperture and focal length), so we can’t tell you what magnification these will give you, or whether the magnification will exceed the resolving power of your telescope. You use the eyepiece with the longest focal length (typically 20 or 25mm) most of the time for finding things and getting an overall view, and then switch to a shorter focal length to look at details.
The 5mm gives twice the magnification of the 10mm on the same telescope. The magnification is objective focal length divided by eyepiece focal lengthy, so shorter focal length eyepieces give higher magnification.