A lens placed before the eyepiece to increase power of the eyepiece. 2x Barlow doubles, 3x triplets, etc.
A lens assembly with a negative focal length placed between an eyepiece and telescope that effectively increases the focal length (and magnification) of a telescope. Barlows commonly come in magnifications of 1.5x, 2X, and 3X.
Device which increases the focal length of an objective lens or mirror Effectively multiplies the magnification of any eyepiece. Common models include 2X, 3X, etc. Often used too aggressively by beginners. Also see focal reducer.
a concave lens that when placed between a telescopes objective lens or mirror and the eyepiece, will increase the magnification of the telescope
a device which has the effect of increasing the magnification
a great accessory for any telescope and will help increase your magnification as well as your eyepiece collection
an accessory that boosts the magnification of any eyepiece you use with it
a negative lens in a special mount
an inexpensive way to extend your eyepiece collection since, for example, two eyepieces and a barlow would be equivalent to having a total of four eyepieces
A diverging lens which has the effect of increasing (usually doubling) the effective focal length of the telescope.
A barlow acts to increase the effective focal length of a telescope providing higher magnification for any given eyepiece. For example, a 2X barlow will double the magnification of a given eyepiece. back to the top
A small negative lens that amplifies and relocates a telescope's beam when placed just inside focus. It is used to obviate the use of short-focus eyepieces and in negative lens projection photography.
An intermediate concave lens place in front of the eyepiece of a telescope to increase magnifaction.
Put a Barlow lens between the main mirror or lens of your telescope and its eyepiece and increase the magnification. Effectively it increases the focal length of the main mirror or lens. The most usual magnification for a Barlow lens is X2. In practice, they are rarely used since they cause a large light loss in the telescope. It is a cheap way of getting a short focal length eyepiece. Better to spend more on an eyepiece, you get better quality.
The Barlow lens, named for its creator, the English engineer Peter Barlow, is a diverging lens which, used in series with other optics in an optical system, effectively increases the focal ratio of an optical system as perceived by all components after it in the system.