Keep in mind that as magnification is increased, the brightness of the object being viewed will decrease; this is an inherent principle of the physics of optics and cannot be avoided. If magnification is doubled, an image appears four times dim- mer. If magnification is tripled, image brightness is reduced by a factor of nine!

Use of 2-Inch Eyepieces (XT8 and XT10 only)

All SkyQuest telescopes are designed to accept eyepieces with a barrel diameter of 1.25". The XT8 and XT10 have 2" focusers that accept both 1.25" and optional 2" eyepieces. At low magnifications, 2" eyepieces can provide a wider field of view than standard 1.25" eyepieces. A wider field can be desirable for viewing extended deep-sky objects that are too large to fit within a narrower field of view.

To use 2" eyepieces, simply loosen the two large thumbscrews on the 2" adapter that are just in front of the thumbscrew that holds the provided 1.25" adapter in place (Figure 13). Once these thumbscrews are loosened the adapter comes off, exposing the 2" diameter focuser drawtube Now, insert your 2" eyepiece into the drawtube and secure with the two thumb- screws loosened previously, and you’re ready to observe.

Tube Balance

SkyQuest IntelliScope Dobsonians are designed to balance with standard supplied accessories, such as an eyepiece and a finder scope. But what if you want to use a larger finder scope or a heavier eyepiece? Traditional Dobsonian designs require the user to compensate by adding weight to the oppo- site end of the telescope tube. Such counterweighting systems can be expensive and unwieldy. The CorrecTension system of the SkyQuest IntelliScope Dobsonians, however, solves the finicky balance problem. The brake pads press against the altitude bearings on the optical tube and increase the friction. With CorrecTension, the added weight of front-end loads will not adversely affect the balance of the telescope. Simply tight- en the tensioning knob to balance any extra load.

Carrying the Telescope

Transporting the SkyQuest is easy to do. The tube uncouples from the base and each component can be carried separately. The base has a handle for easy carrying. With the retaining and tensioning knobs of the CorrecTension(XT) system hold- ing the optical tube captive on the base, the entire telescope can be carried as one unit. (This is not practical for the XT10 due to its hefty weight and size.) This requires some caution, however. If the telescope is lifted improperly, the tube could swing down and hit the ground.

First, point the optical tube straight up (vertical). Remove any eyepieces from the telescope and eyepiece rack, and place them in an eyepiece case. Grasp the handle on the front of the base with one hand while supporting the telescope tube vertically with the other (Figure 17). Now, lift the telescope by the handle. Once the telescope is in the horizontal position, you can carry the entire unit with one hand while supporting the optical tube with the other hand.

If you wish to carry the optical tube and base separately, sim- ply unthread the retaining and tensioning knobs until they are free of the base and optical tube (make certain the spacer does not fall off the retaining knob). Lift the tube off the base, then rethread the knobs back into the bearings so that you do not lose them. Be careful, however, not to bend the knobs when transporting the telescope tube. Do not use the naviga- tion knob as a carry handle! It is not designed to support the weight of the telescope tube and could break off or damage the tube.

Note: The SkyQuest may be too heavy for some users to lift and carry as one unit. Do not strain yourself! If the load seems too heavy, carry the base and tube separately.

When putting the SkyQuest into a vehicle, common sense prevails. It is especially important that the optical tube does not get knocked around; this can cause the optics to become misaligned, and could dent the tube. We recommend trans- porting and storing the tube assembly in an optional padded case for proper protection.

 

Figure

17.

Picking

up and

 

carrying the SkyQuest IntelliScope

 

as a single unit (with tube held

 

captive on the base) requires some

 

caution. (a) First, position the tube

 

vertically. Then grasp the handle

 

on the base with one hand while

 

supporting the tube with the other.

 

This ensures that the tube will not

 

swing down and impact the ground

 

(b) With knees bent, slowly lift the

 

base while supporting the tube.

 

(c) As you lift, continue to support

 

the tube with one hand to keep it

 

parallel with the ground. Make sure

 

you are comfortable with the weight

 

of the

whole

assembly

before

a.

attempting the carry it!

 

b.c.

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Orion XT6 instruction manual Use of 2-Inch Eyepieces XT8 and XT10 only, Tube Balance, Carrying the Telescope