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Small aperature refractors? I don't get it?

Started by kcstargazer2002, 03/27/2004 02:40AM
Posted 03/29/2004 06:36AM #10
For views of non-faint open clusters, it is pretty hard to beat the view from a small refractor.

For crisp views of the planets, it's hard to beat a small APO refractor (even though you may well get more actual detail in a larger scope, the image may not be as "clean" and aesthetically pleasing as in the refractor).

For a grab and go scope, it's pretty hard to beat a small refractor (though those cheap 25X100 binoculars are starting to give it a run for it's money).

I've got an old UO optics 80mm refractor, and I've got astigmatic eye sight. I can't tell the difference between it and APOs at low to medium power, so I wouldn't be spending big on a TV85.

But, by way of contrast, my friend has much sharper vision than me, and he says he wouldn't want my scope. For the last seven years he's been moaning about the Pronto his ex took from him when they split. Even though she left him a Vixen 4" APO, it just wasn't as handy as the Pronto (though it has the superior images).

To summarise, with my eyesight, I don't get it - except in a few circumstances. But my friend, with razor sharp vision definitely gets it.
Renato
Posted 03/30/2004 05:56PM #11
Ah, I do get it.

I routinely use a 78mm Takahashi as my "grab-and-go-scope."

I have owned a 5" Orion Mak and an 80mm Stellarvue achromat, have an 8" Celestron SCT and 4 and 5 inch refractors (Vixen and D&G).

The 3 inch Tak is virtually flawless optically. I can see more planetary detail in the Tak than I ever could in the Stellarvue or Mak or usually than I can in the 8" SCT (well collimated with Bob's Knobs; nicely figured Ultima 2000).

On Jupiter generally I can see the GRS, mottling in several of the 8-9 bands visible in the scope, etc. It equals the 4" Vixen (which is probably the next scope to retire) and is surpassed only by the 5" D&G in planetary detail detection.

I pick it together with its alt-az mount up with one hand and walk it out of the garage to the observatory pad and back in the dark. Virtually zero cool down time. Mechanically it is a work of art. The focuser is like butter. At even 60x per inch, the focus snaps to. The combination of perfect optics and beutiful mechanicals in a one hand package is what sold me on the scope. Having had a "good" 3" refractor previously, the difference between "good" and "phenomenal" is like night and day.

Is it the perfect scope? Nope. Light grasp is extremely important for most DSOs. While this scope is marvelous for surfing through the Sagittarius summer milkyway and identifying the brighter Messier and NGC objects, it takes imagination and averted vision to extract details from all but the brightest DSOs.

But when I am after fainter objects or more detail, I switch to the 8" SCT. It takes more set up time, more cool down time, etc., but is still readily transportable by auto and with GOTO makes faint fuzzy hunting extremely easy. I found that I was never using the Mak for either casual observing or serious observing, and ended up replacing it with a 5" D&G, which is my lunar, planetary, double star and open + globular cluster scope.

Different strokes...