對大王或波斯燻奴來說, 支鏡的價錢「濕濕碎」啦...noodle 寫:
咁計法...要做到10th mag 即是只要用支 160mm 鏡仔就得啦
推薦大王用 : APM 152/1200
http://www.apm-telescopes.de/apo-152-12 ... 85528.html
但支鏡的重量, 肯定比筆記簿電腦及電源重很多倍, 體積也大很多倍, 是否有違便儶導星設備的原則呢?
對大王或波斯燻奴來說, 支鏡的價錢「濕濕碎」啦...noodle 寫:
咁計法...要做到10th mag 即是只要用支 160mm 鏡仔就得啦
推薦大王用 : APM 152/1200
http://www.apm-telescopes.de/apo-152-12 ... 85528.html
60mm scope has light gathering power of 60^2/45^2 of a 45mm scope. i.e. 1.78 Xopa 寫:
According to LVI SmartGuider user manual version 1.01:
"Medium brightness stars (visual magnitude between 3 and 6) generally yield best performance.
and... technical specification of Guide Star Brightness:
60mm guide scope, 2 seconds exposure = approx 7.5
80mm guide scope, 2 seconds exposure = approx 8.0
100mm guide scope, 2 seconds exposure = approx 8.5
then... what is the guide star brightness requirement for my 45mm scope?? 5.5 mag? 4.5 mag?
FYR,
SBIG SG4's sensitivity is 10th magnitude with 60mm aperture.
咁又係....反正手上仲有部 UMID M1, 祗有三百幾 gram 重. 用佢做 guide 同 goto 應該仲頂得順, 今晚試下直入 12V 睇佢頂唔頂得住先...noodle 寫:opa 寫:咁即係...... 想唔帶電腦又唔想帶 STV 之類...又唔想用支 6" 鏡做 guide scope 就...
祗有去搵多 d 錢買 SG4? 呀?
其實Qhy5 /borg45 加netbook 重量同SG4 加 Borg45 差唔得幾遠
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