Barlow lens: Difference between revisions

Content deleted Content added
m Telescope use: fixing page range dashes using Project:AWB
Tablizer (talk | contribs)
Line 19:
 
The amount of magnification is one more than the distance between the Barlow lens and the eyepiece lens, when the distance is measured in units of the focal length of the Barlow lens. A standard Barlow lens is housed in a tube that is one Barlow focal-length long, so that a focusing lens inserted into the end of the tube will be separated from the Barlow lens at the other end by one Barlow focal-length, and hence produce a 2x magnification over and above what the eyepiece would have produced alone. If the length of a standard 2x Barlow lens' tube is doubled, the lenses are separated by 2 Barlow focal lengths and it becomes a 3x Barlow, if the tube length is tripled, the lenses are separated by 3 Barlow focal lengths and it becomes a 4x Barlow, and so on.
 
A common mistake is to assume that higher magnification equates to higher quality of an image. However, in practice the quality of the image generally depends on the quality of the options (lenses) and viewing conditions, not on magnification.
 
==Microscope use==