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    Question SCT and newtonian reflector question



    I have read that a SCT design has a much larger light obstruction( 30%?) than a reflector. So does a 10" reflector gather more light than a 10" SCT? If so is there a marked difference in seeing DSO's betwwen the two? Just curious. Thanks Derek.
    name: Derek

    Various scopes and such.

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    Hi Derek ...I dont think it is a 30 percent difference ... Lets take my SCT for example ...A 8in sct mirror gathers 50.26in of light ...The secondary on my meade SCT is around 2in. and that blocks 3.14 in of light , so the difference would be 47.12 in of light ...Granted the sct doesn't have a spider holding the secondary so that's a little difference there ...SCTs have a corrector plate holding the secondary ......I can tell you about the meade SCTs ...There primary mirrors are a little oversize and they come with UHTC ..(ultra high transmission coating) To allow more light to reach the eyepiece ...As far as a difference seeing DSOs , A SCT has a lot longer focal length than a relfector of the same size generally speaking ...
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    Thanks for the input. I was just wondering. There sure are a lot of different telescope types. A lot to learn.
    name: Derek

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    There are the standard types ...Refractors , newtonian reflectors (dobsonian,equatorial,alt-az),maksutov cassigran and schmidt-cassigran...As far as standard types then you have the hybrid types like schmidt newtonian,dall-kirk,klevtsov-cassigrain,pfund,toroidal,lurie houghton,argunov cassegrain...Plus a bunch more not mentioned ......I counted 27 different types on wikipedia ...The top four are the most common type , the rest are considered hybrid's and are usually custom made ...
    16in Night sky
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    F4.5 , 90mm refractor 500mm FL , 7in
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