The Standard Tracking Test
After the introduction of the original NexStar 5/8 and the subsequent release of the NexStar GT, the Yahoo NexStar Group has had an ongoing discussion regarding tracking accuracy. This has resulted in the creation of a simple tracking test that can be repeated indoors with most of the NexStar models. As the primary protagonist of this test, I have compiled the results into an Excel (97 or better) spreadsheet which you can download here. Click here to view an HTML version right in your web browser (doesn't require Excel). Instructions for performing the test on your scope are included with the results.
The results posted here apply only to the original NexStar 5/8 and the NexStar 60/76/80/102/114/4/130. All newer models, beginning with the NexStar 5i/8i and 8/9.25/11 GPS scopes, exhibit nearly perfect tracking. With these newer models, if you run the tracking test you should see very little drift. In fact the indoors test isn't necessarily accurate enough to state that the very small amount of drift sometimes seen is actually real. And the uniformity of results from scope to scope indicates that the new tracking correction algorithm is easily able to overcome any mechanical differences in mounts.
If you have an original N5/8 or little NexStar, viewing the results posted here will let you see how the tracking of your particular scope compares to others, however, the group has made no firm conclusion as to what constitutes poor or unacceptable tracking performance. Strictly speaking, these older NexStars were only designed for visual astronomy - not astrophotography. So, as long as objects stay in the field of view long enough for your visual enjoyment, your scope tracks well enough.
We now have enough results posted to have a good idea of the general accuracy of the NexStar GT and NexStar 5/8 scopes. Thus I no longer post new entries.