大致而言
小口徑 (< 100 mm) 以透鏡折射式 (e.g. 傳統的單/雙筒望遠鏡) 為最佳
中大口徑 (100 mm ~ 5,000 mm) 以拋物面鏡反射式 (e.g. 牛頓/SCT) 價錢比較低重量比較輕
http://en.wikipedia.org/wiki/Reflecting_telescope
http://en.wikipedia.org/wiki/Maksutov_telescope
http://en.wikipedia.org/wiki/Gregorian_telescope
http://en.wikipedia.org/wiki/Ritche...;tien_telescope (RCT)
http://en.wikipedia.org/wiki/Schmidt-Cassegrain (SCT)
http://en.wikipedia.org/wiki/Schmidt-Newton_telescope (SNT)