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leave the lens cap off the objective lens, tilt the objective (front) lens face down, and 
wait until the telescope reaches room temperature.  
 
With the diagonal mirror already attached and in place, we recommend starting your 
viewing with the low power 20mm eyepiece because it gives you the widest angle with 
the brightest and sharpest views. To adjust the angle of the telescope, loosen the 
azimuth lock knob by turning it counterclockwise. Adjust the telescope to the desired 
angle, then tighten the azimuth lock knob. 
 

NOTE: When using the diagonal mirror, objects will appear right-side up in your 
telescope, but reversed, like a reflection in a mirror. This is normal, and does not 
indicate a defect. 

 
 

Care and Cleaning of Optics 

 

Optical components of a telescope get dirty over time. Dirt or dust on a lens should be 
removed only with the utmost care. A considerable amount of dirt or dust would have to 
accumulate on the optical surface before your view would be compromised. 
 
1.) Keeping any dust caps on during storage and transport will reduce dust collection. 
 
2.) Condensation may collect on the optical surfaces when the telescope is not in use. 
Remove the dust caps and allow the moisture to evaporate naturally. Point the telescope 
downwards to minimize the accumulation of airborne dust. 
 
3.) Once all moisture has evaporated, replace the dust caps. 
 
4.) Filtered compressed air may be used to remove surface dust from lenses and 
mirrors. Remove the dust cap and the dew shield.  Once removed, point the can away 
from the lens and gently expel some air and any condensation or dust that has 
accumulated on the discharge tube. Spray the lens or mirror with short bursts of air to 
carefully remove the dust particles. DO NOT HOLD THE TRIGGER OF THE 
COMPRESSED AIR CAN FOR EXTENDED PERIODS BECAUSE PROPELLANT FROM 
THE CAN MIGHT ESCAPE AND DAMAGE THE OPTICAL SURFACE.  
 

If, after several attempts, you cannot remove the particles, take the telescope to an 
optical professional for cleaning. 
 

Summary of Contents for C90T

Page 1: ...The Educational Fun Telescope from orbitor ...

Page 2: ...ny telescope without adult supervision Here are the main parts of your C90T A 20mm Eyepiece B Focus Tube C Telescope Tube D Dew Shield E Diagonal Mirror F Focus Knob G Azimuth Lock Knob H Objective Lens Not in view I Altitude Lock Knob J Altazimuth Mount K Aluminum Tripod Leg L Dust Cap M 4mm High Power Eyepiece N Tripod Supports D H J I K N A B C E F G L M ...

Page 3: ... rings in addition to dozens of galaxies star clusters and nebulae huge glowing areas in the night sky The C90T also delivers great views of mountains valleys and many other subjects near and far in the world around us You can use the C90T as a terrestrial land telescope to study animals and landscapes at a distance To obtain the best performance from your new telescope please read this manual car...

Page 4: ...ace the telescope tube over the altazimuth mount Lower the telescope tube onto the mount so that the plastic tongue on the mount slips into the bracket underneath the telescope tube Picture 2 4 One of the short bracket arms has a hexagonal shaped cutout around its opening Insert the nut from the altitude lock knob into this cutout Insert the altitude lock knob through the bracket and tongue as sho...

Page 5: ...nsert the low power eyepiece marked H20mm into the diagonal mirror Tighten the small chrome set screw by turning it clockwise to hold the eyepiece securely in place Picture 5 THE ALTAZIMUTH MOUNT The C90T telescope is fitted with an Altazimuth mount Altitude refers to the vertical or up and down movement of the telescope while Azimuth refers to the horizontal or side to side movement ABOUT MAGNIFI...

Page 6: ... your telescope outside Viewing objects through closed or open windows is not recommended Your view can be distorted by reflections in the glass of a closed window or by air currents of differing temperatures passing through an open window 2 Let your telescope adjust to the outside temperature Your telescope will perform much better if the lenses and the air inside the tube are the same temperatur...

Page 7: ... would have to accumulate on the optical surface before your view would be compromised 1 Keeping any dust caps on during storage and transport will reduce dust collection 2 Condensation may collect on the optical surfaces when the telescope is not in use Remove the dust caps and allow the moisture to evaporate naturally Point the telescope downwards to minimize the accumulation of airborne dust 3 ...

Page 8: ... will give you the locations of the planets as they change position from month to month The Internet is also an excellent source of information starcharts maps and more The popular and more familiar constellations often provide the easiest landmarks to help find the planet s locations and paths of orbit Most people have looked up at night and seen some of the planets without even realizing it A pl...

Page 9: ...e hundreds of stars with the unaided eye The telescope is a light gathering instrument which magnifies the view providing significantly more detail and unveiling more stars nebulae and celestial objects With the aid of a telescope you will be able to enjoy exciting views of Saturn s rings Jupiter s major moons the Orion Nebula and much more 2 Why can t I see anything If you see only gray or black ...

Page 10: ...o move Why is that The constant rotation of the earth makes things appear to move Lower power eyepieces will reduce this effect of movement considerably and allow you to observe an object for a longer duration before you have to readjust your telescope Part 259924 ...

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