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Refractors, Chairs, Mars and Diagonals
My observing chair arrived as a gift a few months ago. The added
flexibility of an adjustable seat height over the fixed height of the stool I had previously used has resulted in a change in the way I use Excaliber, my 5 inch refractor. Excaliber used to be mounted on a tripod with the legs extended only a little. A star diagonal, rotated as necessary, provided a comfortable eyepiece location. All was well. Then came the observing (StarDust) chair, followed by Mars and a new, open-air, backyard observatory (the "Colosseum"). Mars hasn't gotten much higher than 30 degrees in my sky -- another factor in the below mentioned change. So what difference has the chair made? Besides comfort, the chair (and Mars, and warm weather) has resulted in my using Excaliber straight through, without a star diagonal, pretty consistently lately. Images are no longer mirror-reversed. The tripod legs are extended more to keep the eyepiece from getting too low. The adjustable seat height allows me to maintain comfort as Mars climbs higher and drops lower in my sky. I still have to physically reposition the entire chair from time to time as the earth rotates and Mars moves across my sky -- some things are slow to change ;-) The switch from being the user of a diagnolled refractor to the user of a straight-through refractor came as an unexpected surprise and benefit from owning an observing chair with an adjustable seat height. Chances are, for me at least, this change will be a seasonal thing. To be used straight through I have to unscrew the eyepiece adapter from Excaliber's focuser, screw on an extension tube, and screw the eyepiece adapter onto the rear of the extension tube. This is fine in warm weather; but in Montana winters I will probable go back to using the star diagonal. With the diagonal I don't have to do any screwing on or off of accessories. Naturally, for objects high in my sky, regardless of temperature, I'm likely to use a star diagonal, though one of these nights I need to check out how high I can point Excaliber and still comfortably observe straight through. The 90 degree angle, allowing me to face at right angles to the sun, is too good to give up for solar viewing as well. Anyway, I just thought I would let people know how an observing chair can change how a person uses a refractor. The bad side: Now my argument for purchasing one of those super-duper MaxBright diagonals has been weakened a bit. Bill Greer |
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