Are SCTs really portable? Well, sort of. Above 8-inches, the SCT enters the realm of "transportable" rather than "portable." Even with an 8-incher, expect to spend considerable time loading and unloading and preparing the telescope for the night's observing run. An 8-inch CAT, especially a fork-mounted model, may not exactly be lightweight either and may require a lift of as much as 50 pounds to place the telescope and fork on the tripod. What is the setup of a Schmidt Cassegrain like? When transporting a scope to a dark site where it can really rock and roll, the routine goes something like this:
I drive onto my club's observing field and start looking around for a good place to setup. While I'm hunting for a reasonably level spot for the tripod, the Dobso-nian owner next to me has pulled her scope's simple wooden mount out of the backseat of her car, plunked the 10-inch scope's tube down in this "rocker box," inserted an eyepiece, and is ready to go. Not me. Not by a long shot.
With the tripod set up and adjusted to the proper height, I manhandle my Nex-Star 11 SCT's case out of the trunk. I'm glad it's got wheels since the scope and case combo approaches 100 pounds. I position the case as close to the tripod as I can so I don't have to move the 66 pound tube and fork mount far. After gingerly lifting the scope onto the tripod, I hunt around for the three bolts that attach the CAT to the tripod and insert and tighten them.
The CAT is on the tripod with just a little cussing from me, but it's far from ready to observe anything. Not without power. I return to the car for two 12-volt battery packs, one for the telescope and one for the dew heater that keeps the 11-inch SCT's big corrector lens dry. Luckily, for once, I've remembered to bring power cords for both batteries. Ready yet? Not yet.
Not only will I need eyepieces to look through, I'll need a little optical device called a star diagonal so I don't strain my neck while looking. I gather these items, remove and store their covers, screw the diagonal onto the rear port of the telescope, and insert an eyepiece. I can't start viewing yet, though. Not until I get the NS11's go-to computer aligned on the sky by sighting a couple of bright stars. Before I can do that, the "finder" telescope will need to be attached to the main telescope's tube and maybe aligned on a bright star so I can get those initial alignment stars in the field of view of the CAT without a struggle.
If I'm going to be doing any imaging on this evening, I need to set up a table for the laptop, haul its battery out, and connect the PC to the telescope. Next to me, my Dob-using neighbor is happily observing Saturn.
This is an accurate depiction of what is involved in setting up the average SCT. Remember, though: once the CAT is assembled, it can do a whole lot more than any Dob. It is virtually a portable observatory. The average SCT does not dictate its owner's choice of vehicle, either. I have seen 14-inch CATs transported in subcompact autos—including a tiny Geo Metro. A Dobsonian that size may demand an SUV or pickup truck.
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