Everything about The Barlow Lens totally explained
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.
In its
astronomical use, a Barlow lens may be placed immediately before an
eyepiece to effectively decrease the eyepiece's
focal length by the amount of the Barlow's divergence. Since the
magnification provided by a
telescope and eyepiece is equal to the telescope's focal length divided by the eyepiece's focal length, this has the effect of increasing the magnification of the image.
Astronomical Barlow lenses are rated for the amount of magnification they induce. Most commonly, Barlow lenses are 2x or 3x but adjustable Barlows are also available. The power of an adjustable Barlow lens is changed by adding an extension tube between the Barlow and the eyepiece to increase the magnification.
The amount of magnification is one more than the focal length of the Barlow lens and the eyepiece. If the length of a standard 2x Barlow lens' tube is doubled, it becomes a 3x Barlow, if the tube length is tripled, it becomes a 4x Barlow, and so on.
In
microscopy the Barlow lens is used to increase working distance and decrease magnification. The lens are "objective lenses" that are mounted in front of the microscope's last objective element. Standard lenses are 2× which decreased the working distance by half and increases the magnification, 0.75× which increases the working distance proportionally to the 0.75 and decreases the magnification similarly. A 0.5× would double the working distance and half the magnification.
Further Information
Get more info on 'Barlow Lens'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://barlow_lens.totallyexplained.com">Barlow lens Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |