Manufacturer: -TS Zubehör
Product number: Ronchi

EUR 49,90

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  • On stock

rating: 5.0 of 5
  • Details..
  • Technical data..
  • In the box..
1.25" Ronchi eyepiece to star test your telescope
Just put it into the 1.25" receptacle of your telescope and point at a star of medium magnitude. Best is the pole star as no tracking is need in this case. Then, you will se a stripe pattern.

The closer you are to focus, the less stripes are visible and the more sensitive is the test. Three to five stripes are optimal.

By interpreting the stripe pattern, you can classify optical abberations and the overall quality.

In combination with the star test, you can make much more useful statements about an optical system an an interferometric test can do.

Advantages and characteristics of the Ronchi eyepice:
Precise aluminium body with 1.25" diameter - no tilting
Fine optically polished glass substrate with precise grating for high test precision
The grating side of the glass is exactly on the same level as the hard stop of the 1.25" barrel. So the focal plane of the telescope can be measured exactly.
10 lines per millimetre allow a test precision close to a optical bench

How do I use the Ronchi eyepiece?
Operating is easy. Just put it into the focuser as any other 1.25" eyepiece. Aim at a star of medium magnitude and center it. A comfortable star especially for Dobsonians and other telescopes without tracking motor is the pole star as it does not move and has the correct brightness.

Turn the focus wheel until 3-5 stripes are visible. Then, examine the stripe pattern.
Lines straight and parallel: Everything is OK
Curved lines: Hint to spherical abberation
V-shaped pattern: Decollimation or Astigmatism
Lines with "hills" or "valleys": Hint for a zone error

Illustrated manual
There is a manual with sample images, you can download the PDF here.
Barrel size:1.25"
Material:Aluminium and optically polished glass
Linien:10 lines / millimetre
Ronchi eyepiece

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Written by Hermann Schieder
on 2023-11-01

"Gutes Produkt zum fairen Preis. Konnte so schnell die Qualität meiner Optiken prüfen und die Fehler lokalisieren. "

Written by Mark Dunnett
on 2022-07-01

"As yet untested on telescopes. But examined under magnification the grating looks excellent. Mark."

Written by Heinz Tovar
on 2021-11-24

"Nützliches Prüfmittel für den Astro-Amateur. Ist leider auch unter Astro-Freaks nur wenig bekannt. Wenn man die Abbildungsfehler seiner Teleskop-Optik nur anhand der Beugungsringe von Sternen beurteilen kann, dann ist das im Vergleich zum Ronchi-Test viel schwieriger und unsicherer."

Written by Johannes Josefsen
on 2021-09-01

"Worked as intended and seems well made."

Written by Markus Bruhn
on 2021-08-14

"Für mich ist dieses Okular ein Muss !"

on 2021-05-25

"For my own tests. Quality is ok. It works. "

Written by Steffen Wetzel
on 2019-11-20

"Man kann damit einen Eindruck über die Qualität der zu testenden Optik bekommen. Das Ronchi-Okular ist eine Möglichkeit von mehreren. Man kann das Ronchi-Okular empfehlen, aber auch andere Testergebnisse am realen Stern mit hinzuziehen."

Written by Alexander Reinders
on 2018-01-09

"Gibt völlig neue Einblicke in eigene Instrumente. "

Written by Jürgen Knabe
on 2017-05-31

"sehr einfacher und eindeutiger Optiktest, kann ihn nur empfehlen"

Written by Robson Ribeiro
on 2017-04-21

"hervorragende Qualität der Produkte"

Written by Martin Mazanek
on 2016-11-25

"In Ordnung"

Written by Felix Lion
on 2016-11-03

"Schönes Teil."

Written by Volker Dr.Uhlich
on 2016-05-20

"Das Ronchi Okular hat mir gute Dienste geleistet.(Celestron C11)."

Written by Fabio Sperduto
on 2016-02-03

"Sehr passgenau, absolut kein spiel."

Written by Ansgar Frendel
on 2015-12-18

"Zeigt an meinem Spiegel schöne parallele Streifen, sehr gut. Im Ernst: Einfach anzuwenden und eine Beschreibung zur Qualitätsbeurteilung ist dabei. "