In May 2002 Celestron introduced new 'modular' NexStar scopes - the NexStar 5i and 8i.
Several details are available at their web site (www.celestron.com) but the following information is not
in their standard 'marketing
- When polar-aligned on a wedge, autoguiding and manual guiding are workable. While
certainly not as effortless as is possible with worm-gear driven systems, the spur gears
do keep the cost down. This allows for inexpensive entry into lightweight imaging and in
fact should work quite well on film.
- The manual hand control, previously supplied as standard equipment, provides EQ North and EQ South
tracking. So, if you polar align on a wedge, it will track at sidereal rate on the RA
axis. You just need to manually find objects. (how low-tech :-)
- Autoguiding (via the Auto Guide port) works whether you are
using the manual or the computerized hand control. Again, with
the manual hand control you would need to mount the scope on a wedge, perform a polar
alignment and activate EQ North or South tracking.
- The RS232 command set for the computerized hand control is the same as the NexStar GPS hand
control. So, it is compatible with any program that supports the NexStar GPS - TheSky,
Starry Night, Cartes du Ciel, etc.
- The computerized hand control does have cordwrap prevention.
- Tracking with the computerized hand control is excellent, keeping
objects in the field of view for as long as you care. This is a big
improvement over the performance of the original NexStar 5/8.
- The new computerized hand control will not work with the original NexStar 5/8.
- The only way an original N5/8 can be upgraded is with replacement of
significant electronic parts in the drive/mount unit. Celestron has not decided if
they will offer that service and if they do the mount would need to return
to Celestron for the upgrade. You are probably better off looking for a
buyer for your old scope (most likely the best you could get would be half the 2002 sales
price) and then buying one of the new scopes.