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Ralph Ford

IC 63 and IC 59

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A shootout wins the shootout this week...

11/09/2004 12:00AM

A shootout wins the shootout this week...

This week's winning review compares an Orion 80mm f/7.5 ED Apochromatic Refractor with a Masked 80mm Televue 102 Apochromatic Refractor.


I don't see how this review has any meaning. I've owned a TV102 and used an Orion 80 several times. They are leagues apart in performance.<br><br>The comparison of an Orion 80 mm apochromatic refractor telescope to a masked down--ie, crippled--Televue 102 mm apochromatic refractor telescope has no validity. No one would buy a TV102, which is already working at f/8, and mask it down further to f/10 for routine use; to compare this to the f/7.5 Orion is ludicrous. Furthermore, the author seems unable to note meaningful differences between the telescopes. Of the six comparisons he made, he was unable to tell a difference in four. The only object which the Orion showed superior performance in this trial was the Perseus Double Cluster, a braod, wide object in which the stopped down (to f/10!) Televue would be at a distinct optical disadvantage. Finally, he may have biased the performance of both telescopes by using suboptimal eyepieces and diagonals; TeleVue's Everbright diagonal is 99% refflective across the visual spectrum, not 96%. <br><br>What this review shows is that if you handicap a really great telescope badly enough, by reducing its aperture and subjecting it to inferior eyepieces, it will give you no better performance than a lesser telescope. I suppose I could outrun an Olympic sprinter if the sprinter had to wear 40 pound leg weights. <br><br>A more meaningful comparison to establish the credentials of the Orion 80 would be to compare the Orion 80 to a TeleVue85, using first quality eyepieces and diagonals. <br><br>Robert Howe