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reflector vs. refractor

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#101 RGM

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Posted 07 February 2004 - 10:06 AM

I just found this thread and can not believe that I read the whole thing. I have owned a reflector and like many really enjoy to observe. Many good points have been raised. Unfortunately, this topic will never be resolved. One saying that I always use is "a telescope that is not used is useless". Personally, I must have a GEM with only motors drives, no GOTO. I still like the HUNT. I prefer refractors for numerous reasons, all of them already mentioned. I love contrast. Nothing is more beautiful than a star cluster with pinpoint stars against a black sky. A large DOB reflector does not meet my needs. To say it is a poorer telescope is crazy. I use my telescope every clear night. Therefore it is the best telescope for me. One other point. Everyone talks about the scope itself and the main objective. No one mentions accessories. I have an average scope with excellent accessories. I use Televue and Pentex EPs, and a WO 2" diagonal. My optics are collimated perfectly and I am getting 100% out of my 120mm objective. Some day I hope to have an APO refractor around 100mm, and a reflector around 10 or 12 inches on a GEM, in my own observatory. Clear skies.



#102 pete

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Posted 07 February 2004 - 12:25 PM

hi pete, at the risk of continuing this thread until the sun turns into a red giant and vaporizes all of us

Erik, I do not believe the refractor was originally designed for astronomy. The idea was to site land or other ships. Something handy to bring up to the eye, just by chance Galileo took it outside one evening and saw craters on the moon. Apparently the instrument could be used for both terrestrial and astronomical objects. However, the Newtonian reflector was designed for astronomical purpose. I agree each of the designs have their flaws and merits. I find owning both; it boils down to what you’re viewing in the sky and how you want to see it. I enjoyed the view of Jupiter in cancer next to the beehive mostly with my Orion Transporter refractor. The F.O.V was wide enough to capture both objects at the same time…spectacular. My reflector with a 1200mm focal length afforded a narrow view not wide enough to accommodate both. Well it’s not like you can’t buy a fast Newt that will do the same. This is a great thread for people to gain insight on both types. The thread sets no limits on the criteria on which to base a decision as far as superior design. I will however commit to a position before I am vaporized by the Sun. No limiting considerations reflectors are the way …Pete

#103 erik

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Posted 07 February 2004 - 01:25 PM

hi pete and bob, i agree, each scope can serve a different purpose, that's why i have a newt and a refractor(and i've pared down to get to only 2 scopes) and the accesories do make a big difference. for example, my $100 orthosopic EP's walks all over any of my meade super plossls, which are only $20.00 less in price. i don't have any televue EP's, somehow i can't justify spending $400 on one EP, but i have looked through them and they're very nice. i think with EP's, once you get to a certain point, you have to spend a lot more to notice a small gain. that's why i think that plossls are so popular, they're cheap and they work well. that's one of the strong points of newtonians- they're cheap and they work. i think, sometimes, when beginners go to star parties and find out what some of those APO refractors and high- end EP's cost, it can discourage them. a lot of people don't realize that you don't have to spend $5000 to see the sky, and i've run into some high end refractor owners that perpetuate it by looking down on newt users. even though, regardless of all of the differences that we've discussed in this thread, let's face it, the differences are really small. most beginners couldn't tell the difference between the views in a 7 inch refractor or an 8 inch reflector.(btw,i've only met a few refractor owners that we're snobby. most aren't) and i agree with bob, whichever telescope gets you outside is the best one for you.

#104 jrcrilly

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Posted 07 February 2004 - 01:29 PM

that's one of the strong points of newtonians- they're cheap and they work.


I think you mean that cheap reflectots tend to work better than cheap refractors, with which I can agree. It's a mistake to class all Newtonians as cheap, though. I traded an APO plus cash for one of mine!

#105 erik

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Posted 08 February 2004 - 02:16 PM

john, yes you're correct, i should have been more specific.there are certainly many newts that cost more than many refractors(like your truss dob, for example), but generally, with a reflector and refractor having the same features, the newt will usually cost less. and it's true even at the bottom of the scale,a 4.5 inch newt usually costs about the same as a 70-90mm achromat from the same manufacturers, and i think, for a beginner, the 4.5 inch will show them a lot more(provided,as dude said, that they can learn to collimate it, which isn't nearly as difficult as some people make it out to be) also, my personal experiance is that, with the VERY low end department store scopes that beginners often acquire, the refractors are horrible, stopped way down and often have uncoated lenses, wheras the newts , although also atrocious in quality are somewhat more usable and can be made to work (through cheap modifications) easier than refractors normally can. obviously, i think no one should own a dept store scope, but if they're "lucky" enough to receive one as a gift, theyd be better off with the newtonian. the low end refractors made by tasco and the like will make sure that they DONT get into astronomy.just my take on things

#106 eric moerman

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Posted 09 February 2004 - 07:23 PM

I have been so free to look for 2 pictures of jupiter taken whit a 8"TMB apo and the 2 one whit a 10" newt.(R.F.royce mirror)
We al know the difference in price between the 2 so take a look for yourself to see wich one is best.

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#107 eric moerman

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Posted 09 February 2004 - 07:24 PM

10"reflector

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#108 Tom L

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Posted 09 February 2004 - 08:32 PM

Were they both taken by the same photographer using the same camera, etc? These demonstrate that the photographers of both pictures are very good!

#109 wes

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Posted 09 February 2004 - 09:40 PM

I have been so free to look for 2 pictures of jupiter taken whit a 8"TMB apo and the 2 one whit a 10" newt.(R.F.royce mirror)
We al know the difference in price between the 2 so take a look for yourself to see wich one is best.


Hi Eric ,

I'm a Reflector fan myself and the reflector image in this comparison is certainly the best one but IMO I don't think this particular comparison is a fair one , the images were taken by two different people at different locations and different dates so in this case I believe the seeing was the deciding factor and not necessarily the scope design .
The refractor image looks like the one Jim Phillips recently posted on the Astromart forums , the image by Eric Ng is amazing and does show what a good reflector is capable of .

Thanks,

Wes





#110 lighttrap

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Posted 09 February 2004 - 10:26 PM

One of the things that digital imaging and stacking and computer processing has inadvertently done is to render astro images posted on the web of far less comparative value than might at first be assumed. Add to that the excellent point made by Wes, above, that comparing the posted images of two different astronomers, made on two different nights, with two different whole sets of circumstances and with two whole different cameras and photo processing abilities, and it all adds up to being of not much value for establishing anything concrete about the raw abilities of the scopes that were but one integral component in the whole process.

Having said that, I'll say something else that should fit in somewhere in this thread:
Refractors are often touted as being more portable than reflectors. I don't buy that, if one factors in the necessary mounts. A meter long refractor mounted on a GEM or CG-5 or SkyView Pro is no more portable in practical terms than a meter long reflector mounted on a GEM or CG-5 or SkyView Pro. The limiting factor to portability is almost always the mounting system, when one gets above about 90mm or so. To take it a step further, I think it's both quite telling, and quite amusing that currently Orion is shipping their 80ED on the same mount as their SVP 8 EQ. Let's see 80mm of refractor vs 200mm of reflector....?

I'm not trying to beat this dead horse any more. In fact, I own both refractors and reflectors. Each has their place. But, it's important that folks look at the whole debate with a bit of detachment and really try to see what's best for their viewing styles and pleasures. This is a debate that never ends on any astro forum that I've ever seen. It just goes on and on and on like a zombie version of the Energizer bunny.

A lot of refractor owners tout the ability to cleanly split close doubles. For some of us, that's just not something that's of any interest at all. For others, looking at a little bit of fuzz that sometimes looks more like lint on the lens, isn't really terribly important. Horses for courses, etc. I'd encourage folks to get beyond thinking in terms of type, and think in terms of which tool is best for what job.

Mike Swaim -- who just loves those faint fuzzies and the time travel they imply.

#111 lighttrap

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Posted 09 February 2004 - 10:34 PM

Ggrrrrr ! Why do I lose the paragraph breaks after a simple grammatical edit? I like this site and these forums, but the template reminds me of my **** VCR; too many features to be actually user friendly.

Forget the graemlin faces, I just want paragraph breaks! ;-(

Mike

#112 Charles

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Posted 09 February 2004 - 11:16 PM

I think the TMB has better detail and less noise than the reflector when you show them in the best way to compare two images shot with different cameras, different processing skills, and shot in different locations with different sky conditions.

Give me a Break!

Charles

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#113 erik

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Posted 09 February 2004 - 11:36 PM

hi mike, i agree, the ONLY way to fairly compare two scopes, is to do it on the same night, side by side.and even that can sometimes leave possibilities open.for example, one scope could be at a slightly different height or closer to a polluting light that would cause an image degradation, or if the mount is sturdier on one scope than the other,etc, etc....i think the best way to compare scopes would be to use them both, side by side,in different locations, for an extended period of time.then you could get a comparison under different circumstances and seeing conditions. oh, and people actually use refractors to split close doubles? every time i try that with my refractor i get all this strange violet purple blue stuff in the eyepiece,and if a put a minus blue filter in, everyhing turns green.is THAT how refractors beat reflectors?....hmm, strange

#114 Stacy

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Posted 10 February 2004 - 02:33 AM

Forget the graemlin faces, I just want paragraph breaks! ;-(


I'm not sure what you mean ... Just a space or do you want indents?

#115 eric moerman

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Posted 10 February 2004 - 03:46 AM

Charels,

the purpose of me posting these 2 pics.was to show that the 2 scopes are pretty close togheter.
I find both images verry close and like some people already mentiond its indeed not fair and defenetly not scientific to compare 2 scopes this way.Buth that was not the point.My point was that if you take a apo and a newt.of the SAME quality and comparibel appartures that they will give comparebel results.
I have been reading here post from people that are saying like a 8" apo would do some magical things and some other posts about newt that say the same.
Thats what i wanted to show that its not like that.
I have read my post again and indeed it was not so clearly writhen,sorry for that :crazy:
I also read constantly here people comparing 15" obsessions whit 6" refractors,ofcorse it will show more detail(if it has a reasenebel mirror)buth if i had the choise between a 8" apo and a 10"(if they would make them)obsession and the likes i know what i would take then.
Yes im a newt. fan because i cant afford a big apo.and whit the years i have learned the skill(thanks to some other people)to build newtonians that perform as well as a good apo.Buth to be honnest,if i should have to build them for a living yes they would have to be almost as expensive as a apo to make a living of it.

Greatings,Eric

#116 Jacques

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Posted 10 February 2004 - 12:08 PM

oh, and people actually use refractors to split close doubles? every time i try that with my refractor i get all this strange violet purple blue stuff in the eyepiece,and if a put a minus blue filter in, everyhing turns green.is THAT how refractors beat reflectors?....hmm, strange


Erik, I respect everyone's opinion and all designs have their place/sky in astronomy IMHO but you're not really serious about this short tube splitting doubles are you?

#117 erik

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Posted 10 February 2004 - 09:25 PM

jacues, no, i was kidding about splitting doubles with my short tube, but i do use it on the planets sometimes, and there's always a lot of chromatic abberation. i know it's not a planetary scope, but it's present even in longer f/ratio refractors- that was my point.and the minus blue filters only do so much, they don't completely get rid of the halo, and as i said, they add a green hue to everything. i just feel like refractors are always a trade off. short focal lengths, and or achromats have the problems i mentioned, and APO's are too expensive and most lack in aperture, unless you have mucho$$$$$$$$.i think all scopes have their place too(after all, i do own a refractor, and have owned many others as well). i just personally find the views in newts to be more to my liking.

#118 Jacques

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Posted 11 February 2004 - 05:32 AM

There's nothing wrong with finding the views in newts more pleasing. Everyone has to live with the particular trade offs each design has, that's why people (just like yourself) have more scopes of different design, for different purposes, for different needs. I choose to/can/must live with the shorcomings of my medium length achromats (4"F10 and 6"F8) and find the views very pleasing in both (personal taste). Aside from physical facts there are as many personal preferences for choosing equipment as there are astronomers (budget, ratio, emotion, needs, location, visual observing, photo's,...). I'm sure I will enjoy a 10" dob someday for pulling in faint fuzzies (don't have macho bucks ;)) Most important thing: I'm having a blast with this hobby and that won't change (equipment most likely will throughout the years).

Clear skies

#119 john-AZ

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Posted 11 February 2004 - 12:51 PM

After reading through this post, I have to conclude that many of us would be better off spending time studying astronomy than discussing / considering the instruments involved (read as: lighthearted but perhaps shade of truth). But some would rather be lawyers than astronomers (read as: reflective humor...given the length and verbose nature of the thread)! Personally, I've never looked through a telescope I didn't like and enjoy (a nice warm fuzzy comment).
John

#120 erik

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Posted 11 February 2004 - 09:11 PM

hi john, i can't speak for everyone else, but i DO spend my time studying astronomy. but i also enjoy the intricasies of telescopes, and i think discussing them with others brings up things that one might not have considered otherwise. i also think that this is a good thread for beginners to read, and by doing so, they may be able to make a more informed decision on which type and size scope they wish to buy.i'm sorry that you didn't find this thread as entertaining as i have .oh, and by the way, i'd rather be almost anything but a lawyer.

#121 pete

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Posted 12 February 2004 - 12:20 AM

But some would rather be lawyers than astronomers.

Gee… John. I wonder who wrote this???

“It's my understanding that an optically superb newtonian >f10 becomes virtually refractor-like. At >f12, one would have a tough time knowing if they were looking through a superb Achromatic refractor vs. a superb APO refractor. The Newtonian and Achromat, if optically superb, can compete with the APO at these optimal f ratios. I have found this to be true through experience by looking through the few scopes thus "optimized" for their design. Ironically, these optimized scopes are rare...in spite of the fact that they are exceptional visual instruments. Portability has it's price.”

Looks to me like most of us could spend a little more time under the sky, and a little less lawyer time on this thread or… others. However, John I suspect this thread will not end until Erik has the first and the last word. Pete



#122 erik

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Posted 12 February 2004 - 12:30 AM

hi pete, are you and john BOTH lawyers?...whoops, looks like i'm trying to get the last word in again. my bad.

#123 john-AZ

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Posted 12 February 2004 - 02:08 PM

The comment about lawyers was supposed to be of humor given the length and nature of some of the replies and thread in general...I didn't mean to touch a soft spot Pete...apparently I offended you...yes I'm a member here and talk the talk as much as most of you. You don't have to defend yourself Pete...I'm not attacking you or anyone else.
With repect to this comment: "Looks to me like most of us could spend a little more time under the sky, and a little less lawyer time on this thread or… others."
I whole heartedly agree...self included
To answer your question about "who wrote this" the clip you selected is sort of an amalgam from several sources but for the most part derived from:
http://www.cloudynig...o/planetary.htm
Erik, I didn't say I wasn't enjoying the post...just making thought provoking conversation which apparently offended you as well...my apologies. As far as beginners reading this thread, I would expect they would find better sources than us! Perhaps those artices written by Roland Christian / Mike Palermiti on this website (and pertaining somewhat to the material of this thread).
I have modified my previous post for clarity.
John

#124 Don W

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Posted 12 February 2004 - 08:41 PM

Well after having a long and spirited discussion with Erik in another area here, I find him to be slightly confrontational but only to the extent that it provokes more thought. In fact, he reminds me of well....me, because that's what I sometimes do. Be yourself, Erik, I'm enjoying it

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#125 desertstars

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Posted 12 February 2004 - 08:53 PM

Dueling graemlins???

:roflmao:


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