NPZ TAL-200K User manual


TELESCOPE TAL-50K
TELESCOPE TAL-200K
Service manual

2
CONTENTS
Page
. General directions 3
2. Specifications 4
3. Standard equipment 5
4. Design and principle 9
5. Optical train 9
6. Telescope assembling 
7. Order of operation 2
7.. Operation with telescope 2
7.2. Photographic observations 2
7.3. Telescope and atmospheric conditions 4
8. Maintenance 5
9. Rules of storage 6
0. Acceptance certificate 6
Supplement. Table of close stellar pairs for testing
image quality of the telescope 7
The telescope is subject to continuous development and improvement,
consequently it may incorporate minor changes in detail from the information
contained herein.
05.04

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. GENERAL DIRECTIONS
ATTENTION!
Telescope TAL-150K, TAL-200K (hereinafter in the text referred to as «tele-
scope») is not intended for direct visual observation of Sun at full operating
aperture. Because of high light intensity an image of Sun in focus of primary
mirror has a high temperature. To avoid on overheating of corrector it is recom-
mended to avoid any direct observation of Sun disk.
One should remember that overheated corrector being in field of direct sun-
light can be out of order or make a turbulent air torrents in telescope tube that
to reduce considerably a quality of image.
Also if it is necessary to leave a telescope out of door (for example, to dry it) one
should orient it so that the direct sunlight do not get into the optical system.
The telescope can operate normally at the ambient temperature from 30°C
to minus 30°C.
It is a precise powerful amateur astronomer telescope. It demands a careful
handling and certain knowledge in the field of astronomy. Only in this case user
will be fully satisfied.
When buying the telescope one should pay attention to the package safety
ensured by the seal of the manufacturing plant. After unsealing the case one
should check compliance of the complete set denoted in the list of enclosure.
Prior to using the telescope one gets acquainted with its handling and order of
operation.

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2. SPECIFICATIONS
Name TAЛ-50K TAЛ-200K
Diameter of objective lens (operating aperture), mm 50 200
Focal length, mm 500 2000
Relative aperture :0 :0
Magnification and angle field of view (changeable):
- with the eyepiece f’=25 mm 60x 80x
40" 30′
- with the eyepiece f’=0 mm 50x 200x
6′ 2′
- with the eyepiece f’=25 mm and Barlow lens 20x 60x
20′  5 ′
- with the eyepiece f’=0 mm and Barlow lens 300x 400x
8′ 6′
Photographic angle field of view 40′ 40′
(23.3mm) (23.3mm)
Screening of pupil in center 3% 2%
Resolution limit 0.8″ 0.6″
Pellucid capacity 2.8m 3.4m
Angular field of view of the finderscope 8° 7°
Magnification of the finderscope 6x 8x
Length tube, mm 425 550
Weight of the telescope, Kg 7.5 

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3. STANDARD EQUIPMENT
Name Qty
Telescope 
Supply unit 
Eyepiece of f’=25mm 
Finderscope 
Accessories and Parts
Eyepiece of f’=0 mm 
Barlow lens 
Reticle 
Blind 
Bushing 
Adapter 
Stopper 
Housing 
Service manual 

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Fig.. General view:
 – telescope tube; 2 – finderscope; 3 – eyepiece
2 1
3

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Fig. 2. Assemble of primary mirror together with eyepiece set:
 – mirror; 2 – bushing; 3 – blending tube; 4 – screws;
5 – ball hinge; 6 – focusing mechanism; 7 – diagonal mirror; 8 – eyepiece;
9 – cover; 0 – back flange;  – screw
1
2
311 10 8
9
7
6
54

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Fig. 3. Corrector:
 - mounting; 2 - reflecting lens; 3 - meniscus lens; 4 - padding ring
2
1
3
4

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4. DESIGN AND PRINCIPLE
The tube 1 (fig.) is the basic part of the telescope, which embodies the optical
units such as a primary mirror, corrector, eyepiece set and finderscope.
The primary mirror 1 (fig. 2) is fastened with the collet bushing 2 in the center
hole. The blending tube 3 on the collet bushing prevents stray light.
The corrector (fig.3) consists of reflecting lens 2 and meniscus lens 3 spaced
by means of padding rings 4 in the mounting .
Eyepiece set (fig.2) consists of focussing mechanism 6, diagonal mirror 7, set
of symmetrical eyepieces f'=25mm and f'=0mm with barrel diameter 3.8mm
(.25”), Barlow lens mounted in the same one.
Finderscope 9 (fig.) is a telescope with 6x (8x) magnification and view field
8° (7°).
5. OPTICAL TRAIN
Telescope is developed on the basis of Klevzov’s original optical train, which
does not use any aspherical surfaces. Klevzov’s optical train (fig.4) consists of
primary concave mirror  and correcting unit consisting of two single lenses 4,5.
The lens 5 is made in form of negative meniscus directed by concave side to the
observed object. The lens 4 is negative one having a reflecting surface.
Reflecting from the primary mirror  a beam passes through correcting lenses
4,5, reflects from the reflecting surface of lens 4, passes through correcting lens
forming an image of observed object in the focal plane which is located behind
a primary mirror .
In the main the Klevzov’s optical train is an improved Kassegran optical train,
which has a spherical primary mirror and double lens corrector having a reflect-
ing surface that to allow reducing an aberration. A meniscus 5 corrects a spherical
aberration and coma and fully compensates a little longitudional chromatic
aberration with the help of negative lens 4. Because two lenses of corrector are
made of the same mark of glass a secondary color of system is extremely little
one, and correction of the residual aberration is perfect that to allow obtaining
an image of observed object which can be compared with the image of object
obtained with the help of mirror telescope. Besides, Klevzov’s optical train is not
subject to unadjastment.

0
The lacks of aspherical surfaces, high quality of correction of the residual
aberration in the wide range of spectrum and small length are indisputable ad-
vantages of Klevzov’s optical system, that to allow satisfying all requirements of
amateur astronomer.
Telescope is completed with two symmetrical eyepieces f'=25mm and
f' = 0 mm and 2x Barlow lens. For easy observation of celestial objects near by
zenith an eyepiece set of telescope is turned to optical axis of tube by 90° with
the help of diagonal mirror 5. To locate an object in the center of view field the
telescope is completed with finderscope 6, which consists of objective lens,
reticle with the cross and eyepiece.
Fig. 4. Optical train of telescope:
 - primary mirror; 2 - eyepiece; 3 - diagonal mirror;
4 - reflecting lens; 5 -meniscus lens; 6 - viewfinder
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2
3
4 5