| Secondary |
| mirror |
| Reflection of |
Front of | your eye in |
telescope | secondary |
| mirror |
Secondary | Reflection of |
reflection of | inside of tube |
inside of tube | (misalignment) |
Figure 2a
Figure 2a: If the telescope’s optics are out of alignment the view through the rear opening of the telescope will resemble Figure 2a.
| Secondary |
| mirror |
Front of | Reflection of |
your eye in | |
telescope | secondary |
| mirror |
Figure 2b
Figure 2b: With the optics properly aligned the view through the rear opening of the telescope will resemble Figure 2b.
Once you are ready to collimate, look into rear opening of the tube. If your telescope is out of collimation, it will resemble Figure 2a, a properly collimated scope will resemble Figure 2b. The direction of the misalignment in your telescope may differ from Figure 2a, but the diagram will give you the gen- eral idea of how things will look.
Note there are six alignment screws on the back of the opti- cal tube, three large and three small. You will need 3mm and 2mm Allen wrenches to turn these screws. These alignment screws push and pull the mirror cell in order to tilt it. When you loosen or tighten one of these screws, the other five screws must be adjusted as well to keep the proper amount of pressure on the back of the mirror cell. By making slight adjustments to how much the screws are tightened and loos- ened, you will change the alignment of the primary mirror.
Look into the rear opening of the tube and locate the black crescent that shows the telescope is out of alignment. (Figure 2a). Note which way the front of the telescope would need to move in order to “fill” that black crescent and resem- ble Figure 2b. Then look at the back end of the telescope and locate the alignment screw that is in the direction that the
front of the telescope needs to move. For example, if the view in your telescope resembled Figure 2a, then you would want to move the front opening of the telescope scope to the right. Then the alignment screw you would start with would be the screw on the right as shown in Figure 3.
Your actions now depend on whether this alignment screw is a small or large screw. Please note that you will be working to adjust the mirror cell by keeping all the screws not too loose and not too tight. Follow the steps listed below careful- ly and refer to the figures that accompany them.
Figure 3 | Figure 3: If the view through | |
the rear opening of the telescope | ||
| ||
| resembled Figure 2a, then the | |
| alignment screw you would start | |
| with would be this one. The | |
| actual first alignment screw you | |
| would pick will vary depending on | |
| which way the front opening | |
| would need to move in order to | |
| “fill” the black crescent. |
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