Barlow Lens

Barlow lenses

The Barlowlens (named after its inventor, the English mathematician and physicist Peter Barlow) is a diverging (negative) lens, which is used to increase the effective focal length. This results in a higher magnification. Moreover, the Barlow lens is very easy to use as the Barlow lens can be placed directly in front of the eyepiece.


Calculating your magnification

Imagine you use a 10mm eyepiece with the focal point of your telescope being 1000mm. Now you have a standard magnification of 100x. With a 3x Barlow lens you will arrive at magnification of 300 x! This is a cost-effective way to achieve a better result. An additional advantage is the ‘flatter’ and sharper image produced by the Barlow lens. A minor drawback is the small optic angle inherent in higher magnifications.

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Frequently asked questions

Bresser 3x Barlowlens Achromaat

Question: Will this fit the Celestron 80EQ?

Answer from our expert: Yes, this should be possible.

Bresser 3x Barlowlens Achromaat

Question: Hi, can you tell me if this will fit a celestron travel scope 70?

Answer from our expert: It will fit, it is not advised though. You could suffer too much light loss.

Bresser 3x Barlowlens Achromaat

Question: will it fit a Celestron astromaster 76eq

Answer from our expert: Yes it will. This Barlowlens will fits all telescopes with a 1,25 inch diameter eyepiece fitting.

Do you have a general question? Please contact our customer service. They will be happy to help you.