Prism, 90 Degree Diagonal Mirror, Erecting Eyepiece

Amici Prisms, 90 degree diagonal mirrors & erecting eyepieces

Telescopes and eyepieces display a mirror image. This phenomenon is present in every telescope. As a result, left and right are reversed and the image is turned upside down. You can use a prism, a 90 degree erecting prism as well as an erecting eyepiece to restore the image to its original condition. This way, you will be able to observe more comfortably!


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90 degree diagonal mirror

The 90 degree diagonal mirror is placed between the eyepiece and the eyepiece tube. This way, the light is bent 90 degrees, allowing easy viewing from the top. The image is upright, yet it is still mirrored. A 90 degree diagonal mirror is essential for Schmidt-Cassegrain & Maksutov Cassegrain telescopes.

Erecting eyepiece

Every telescope shows the image flipped upside down. Using an erecting prism also involves using an eyepiece. First the erecting prism is placed in the eyepiece, after which the eyepiece is shoved into the lens.

Amici prism

An Amici prism or roof prism is a normal rectangular equilateral prism where, instead of the biggest side, the two sides have been perpendicularly ground to each other. The prism actually consists of two combined triangular prisms. An Amici prism provides an upright image in an astronomical telescope. The prism cannot be used in combination with another optical instrument (90 degree diagonal mirror). Please bear in mind that using this prism does involve some loss of light.

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Frequently asked questions

Bresser erecting eyepiece 1.5x

Question: I've googled but can't find out whether or not this correcting eyepice will fit my bresser skylux ac 70/700. Do you know if it does or how I can find out how?

Answer from our expert: Both are 1,25" and will fit/.

Bresser erecting eyepiece 1.5x

Question: will this fit a MEADE EXT-70 ~ to date we have never been able to use this telescope as it came with no eyepiece, thank you

Answer from our expert: Yes, this will fit the ETX-70 telescope. you still need an eye piece though. This erecting eyepiece isn't a real eye piece, but a sollution to turn the image of the telescope upright combined with a real eye piece.

Bresser erecting eyepiece 1.5x

Question: Will this be suitable for the Bresser 80/900?

Answer from our expert: Yes this will work

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