Oldies reflectors, newbies refractors...true?

Got a question on astronomy that you'd wanted to ask? Ask your questions here and see if the old timers can give you some good answers.
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weixing
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Post by weixing »

Hi,
For me, after condersing portability and pricing, a 8" SCT or a 8" F4 Newtonian might be my final scope.

If I've the money to do what the Arief picture show, it'll be a big RC telescope... I can always put an off-axis mask for unobstructed colour free planetary view.... dream on... dream on... :P :P :P

Have a nice day.
Yang Weixing
:mrgreen: "The universe is composed mainly of hydrogen and ignorance." :mrgreen:
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Jeremy
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Post by Jeremy »

I was a reflector man (I had 3 in a row) until I came to Singapore. Then I was converted to refractors, having been exposed to all those lovely Taks, William Yangs, Pentaxes etc. For imaging a small, short FL refractor is hard to beat. Especially when you have to set up and take down quickly in S'pore's variable weather.

So for me, Vin Snr's rule is reversed!

Go well!
Jeremy
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denebman
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Post by denebman »

There is a simple rule that is always ignored. For refractor, the difference of refractive index between objective glass and the air is just 0.5~0.70, which means that slight figuring error on objective lens doesn't change much the overall optical performance. For reflector, if the relationship between incident light ray and reflected light ray is expressed the same way as above mentioned, the difference of refractive index will be much higher, as a result, reflectors are more sensitive to figuring error. In my opinon, catadioptric is the most compromised design regardless of portability.

I don't devaluate reflectors, a well figured Tak reflector justifies all its aperture advantages it carries. At this moment I keep both types with a bit more preference to refractors.
10" Telekit with Zambuto optics~TMB 152/1200 (construction)~Takashi Mewlon 210~TMB 80/600
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qu1xs1lv3r
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Post by qu1xs1lv3r »

i got a reflector as that's what the guy (i forgot his name) from the science centre recommended!!
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ariefm71
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Post by ariefm71 »

what can you get for S$12,000 these days?
One piece of 4" refractor (OTA only): http://www.astromart.com/classifieds/de ... _id=405555 , or
One piece of 3.5" refractor: http://www.astromart.com/classifieds/de ... _id=405710
Last edited by ariefm71 on Fri Jan 27, 2006 12:20 pm, edited 1 time in total.
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ariefm71
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Post by ariefm71 »

whether your oldies or newbies, if you're interested with a good reflector, you may want to consider this: http://www.astromart.com/classifieds/de ... _id=405574 :-)

It's available locally (I just have too many scopes).

cheers,
Arief
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zong
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Post by zong »

Think because reflectors need to collimate often, newbs like me don't like it. I'd rather spend my time looking at the sky! (esp. since i in camp most of the time, my poor "wife" is unused..)

But if i had a choice with lotsa money, one each rocks. cats for portability, buy a bungalow and setup a big refractor there, box up a good reflector in a car to go dark places when nights are good ;))
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Canopus Lim
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Post by Canopus Lim »

If you have a barlowed laser collimator.. no problem, the collimation will be nearly as good as a star test. :)
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