Testing Telescopes
If you know the specific type of telescope you would like more information on, click on one of the buttons just below in the header. If you would like general information about the different types of telescopes available, then scroll down this page for the topic sections about telescopes.
Fixed Focus Telescopes
VISUAL OPTICAL INSTRUMENTS
Testing Telescopes
Vermont Photonics offers the comprehensive line of Möller-Wedel Optical GmbH testing telescopes with:
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fixed and variable focus settings
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straight, 90° and 60° viewing (only with fixed focus setting
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available with mechanical or digital double micrometer
TESTING TELESCOPE
Selection Criteria
The high variability of the testing telescopes of MÖLLER-WEDEL OPTICAL GmbH allows you the perfect choice for your application.
To help you determine which is most appropriate for your application, this section describes the influences of focal length of objective and eyepiece, objective aperture and furthermore of fixed or adjustable focus setting on the testing telescope.
SELECTION CRITERIA
Long or Short Focal Length?
Depending on the magnification of the instrument a longer focal length of the objective leads to a greater measuring sensitivity and measurement accuracy. As the focal length increases, the measuring range (FOV) decreases proportionally. Additionally, the intensity of the light bundle received by the telescope decreases with increased focal length. A longer focal length affects the mechanical extension of the tube, as well.
SELECTION CRITERIA
Eyepiece Focal Length?
In contrast to the usually used eyepiece with f=14.7 mm an eyepiece with f=10 mm gives a larger magnification but lesser image field and eyepiece f=25 mm gives a smaller magnification but larger image field.
Note: After removing the eyepiece cover ring all eyepieces can be upgraded with a C-Mount-Adapter to connect a CCD-Camera to the eyepiece.
SELECTION CRITERIA
Small or Large Objective Aperture?
Light conditions are more favorable when large apertures are used, and the evaluation of the results is easier and more accurate. A long distance between test specimen and testing telescope demands a relatively large free aperture (or aperture ratio). For these kinds of measurements a relatively large aperture diameter should be used.
SELECTION CRITERIA
Fixed or Variable Distance Setting?
Fixed, infinity focus testing telescopes are generally the best choice when testing systems adjusted to infinity. Fixed focus tubes set at other than infinity can be ordered. Also a special alignment to a customized wavelength is possible. (Standard wavelength: 546 nm (Green))
For measurement tasks requiring an adjustable focal distance like adjustment at different wavelength or to different distances, focusable testing telescopes with objective tube with tube extensions are used.
TESTING TELESCOPES
TELESCOPES with FIXED FOCUS Setting
A testing telescope provides a magnified real image of a distant object. Usually the image is at infinity at a
wavelength of 546 nm (Green). But also alignments to 470 nm (Blue) or 660 nm (Red) are possible.
The main components of a testing telescope are:
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objective tube with objective
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reticle sleeve with reticle
Straight Viewing Fixed Focus Telescopes
The testing telescope with straight viewing is adjusted to infinity. Adjustment to other distances or wavelength is also possible on demand. The reticle is positioned at the rear focal plane of the objective. Due to this configuration all objects at infinity are imaged into the reticle plane. The reticle plane is viewed through the eyepiece.
Note: Due to the set-up the image in the eyepiece is rotated by 180°.
For more information on our STRAIGHT VIEWING FIXED FOCUS telescopes, click on one of the images below.
The simplest version of a testing telescope is the testing telescope with straight viewing. Testing telescopes of this version are available with different focal lengths and tube diameters.
Testing telescopes with straight viewing is also available with mechanical double micrometer (FG MD) and with digital double micrometer (FG MDD).
The Type FG MD with mechanical double micrometer allows the measurement of deflection angles in two directions. The movement of the eyepiece reticle in x- and y-direction in the image plane can be read from the scale of the micrometer drums. The scale division (SD) is 5 micrometer.
The Type FG MDD has programmable measuring gauges, which allows the operator to read the angular displacement in arsec or mrad.
90° Viewing Fixed Focus Telescopes
The testing telescope with 90°-viewing contains an additional folding mirror. This kind of testing telescopes is used for vertical set-ups or for set-ups on optical tables or for applications where straight viewing is not practical from point of view of ergonomics and space.
Note: In contrast to testing telescopes with straight viewing the image appears not 180° rotated, but right way up, laterally inverted.
For more information on our 90° VIEWING FIXED FOCUS telescopes, click on one of the images below.
MÖLLER-WEDEL OPTICAL offers the testing telescope with 90°-viewing with different focal lengths, diameters and eyepieces.
Testing telescope with 90°-viewing is also available with mechanical double micrometer (FR MD).
The Type FR MD with mechanical double micrometer allows the measurement of deflection angles in two directions. The movement of the eyepiece reticle in x- and y-direction in the image plane can be read from the scale of the micrometer drums. The scale division (SD) is 5 micrometer.
Note: A version with a programmable measuring gauges (MDD) is not available because of mechanical limits.
60° Viewing Fixed Focus Telescopes
The basic function and design of the testing telescopes with 60°-viewing is same as of testing telescopes with 90°-viewing. The main differences are the angle of the folding mirror with 60° between objective and reticle and that the design limits the variants in focal length (f=300 & 500 mm) and tube diameter (65 mm).
This kind of telescope is ideal for horizontally set-ups, because the 60°-viewing is more ergonomic.
Note: The image appears right way up but laterally reversed.
For more information on our 60° VIEWING FIXED FOCUS telescopes, click on one of the images below.
The telescope with 60°-viewing is also available with mechanical double micrometer (FW MD) and with digital double micrometer (FW MDD).
The Type FW MD with mechanical double micrometer allows the measurement of deflection angles in two directions. The movement of the eyepiece reticle in x- and y-direction in the image plane can be read from the scale of the micrometer drums. The scale division (SD) is 5 micrometer.
The Type FW MDD has programmable measuring gauges, which allows the operator to read the angular displacement in arsec or mrad.
TESTING TELESCOPES
TELESCOPES with ADJUSTABLE FOCUS Setting
Besides testing telescopes with fixed focus setting (fixed distance between reticle and objective) testing telescopes with adjustable focus setting are available. With these telescopes the distance between reticle and objective is adjustable. Such measurements at other distances than infinity or at other wavelength of light can be made.
Straight Viewing Adjustable Focus Telescopes
The simplest version of a focus adjustable testing telescope is the testing telescope with straight viewing. Due to the set-up the image in the eyepiece is rotated by 180°.
For more information on our STRAIGHT VIEWING ADJUSTABLE FOCUS telescopes, click on one of the images below.
MÖLLER-WEDEL OPTICAL offers testing telescopes with adjustable focus setting with different focal lengths, diameters and adjustment ranges
Testing telescopes with straight viewing and adjustable focus setting is also available with mechanical double micrometer (FGV MD) and with digital double micrometer (FGV MDD).
The Type FGV MD with mechanical double micrometer allows the measurement of deflection angles in two directions. The movement of the eyepiece reticle in x- and y-direction in the image plane can be read from the scale of the micrometer drums. The scale division (SD) is 5 micrometer.
The Type FGV MDD has programmable measuring gauges, which allows the operator to read the angular displacement in arsec or mrad.
90° Viewing Adjustable Focus Telescopes
The focus adjustable testing telescope with 90°-viewing contains an additional folding mirror. This kind of testing telescopes is used for vertical set-ups or for set-ups on optical tables or for applications where straight viewing is not practical from point of view of ergonomics and space.
Note: In contrast to testing telescopes with straight viewing the image appears not 180° rotated, but right way up, laterally inverted.
For more information on our 90° VIEWING ADJUSTABLE FOCUS telescopes, click on one of the images below.
We offer the testing telescopes with 90°-viewing and adjustable focus setting with different focal lengths, diameters and eyepieces.
Note: Versions with mechanical double micrometer (MD) or programmable measuring gauge (MDD) are not available because of mechanical limits.
TESTING TELESCOPES
Recommended Accessories
Vermont Photonics offers all of the MÖLLER-WEDEL OPTICAL GmbH testing telescopes accessories providing a perfect match for your application or measurement tasks with a visual collimator.
To learn more about these components, click on one of the four buttons below.
We also recommend contacting us to discuss your specific applications.
RECOMMENDED ACCESSORIES
Attachment Achromats
Can be mounted to a D40 or D65 objective tube to focus collimated beams of collimators, testing telescopes or autocollimators to a specific finite distance.
Art. No. Description Comment
221 048 VA f=50 D10 M36x0.75
221 051 VA f=90 D16 M36x0.75
221 053 VA f=140 D28 M36x0.75
221 055 VA f=200 D28 M36x0.75
221 059 VA f=300 D28 M36x0.75
221 063 VA f=500 D28 M36x0.75
221 067 VA f=600 D28 M36x0.75
221 061 VA f=300 D50 M60x1 only on request
221 065 VA f=500 D50 M60x1 only on request
Testing Telescopes
Overview
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Testing Telescope
Introduction