Ronchi eyepiece 1,25"

Ronchi eyepiece for testing the quality of your telescope on the stars

Simply insert the Ronchi eyepiece into the focuser and aim the telescope at a medium-bright star. The North Star is ideal for this purpose.

Through the Ronchi eyepiece, you will then see a pattern of stripes. The closer you are to the focus, the fewer stripes will be visible and the more accurate the test will be. Three to five stripes are ideal.

The stripe pattern allows you to classify your optics without any doubt and assess their quality. You can also detect optical errors and classify them. Check the lines as follows:

• Straight lines: Everything is fine
• Curved lines: Indicates spherical aberration (aperture error)
• Lines drifting apart: misalignment or astigmatism
• Lines with a peak or valley: Indicates a zone error

In combination with the star test, you will be able to make a clear statement about your telescope, with significantly more practical relevance than an interferometric test can provide.

The advantages and features of the 1.25" Ronchi eyepiece:

• Precise aluminium housing with clean 1.25" barrel – no tilting possible
• Fine-optical polished glass plate with vapour-deposited line grating - for maximum accuracy during testing
• The glass plate with the lines is exactly in the plane where the 1.25" barrel stops. This allows the focus position to be determined to fractions of a millimetre
• Ten lines per millimetre enable a test accuracy that is comparable to tests on an optical bench.

TS Optics is a brand of Teleskop-Service.