唔知似乜的m31, m27. m42 & m45

[Subaru]

都係冬天事........ M42
Vixen AV-102SS Astrograph FL367mm (口徑收至85mm)
LXD75
iso 800
45s x 10

支鏡唔錯喎, 可以做平民版FSQ.

[Wah!!]

雖然係ACF, 但係第二張M27見到佢未做到 Flat field?

唔係好明添 你係覺得邊緣像差冇改善? 我唔係好識睇.

呢個 "flat field" 其實應該係 "field curvature"

[A/45]

Glad to see that! It does has a very flat field.

[Nosneb]

都係冬天事........ M42
Vixen AV-102SS Astrograph FL367mm (口徑收至85mm)
LXD75
iso 800
45s x 10

支鏡唔錯喎, 可以做平民版FSQ.

我覺得收一收光圈都唔差呀, 不過如果用盡塊主鏡的102mm口徑就會有好嚴重色差. 始終係普消鏡要求唔可以太高. 呢兩幅係用左一個自制的摭光罩將主境邊緣的大概10mm擋去. 結果好滿意.

[Nosneb]

雖然係ACF, 但係第二張M27見到佢未做到 Flat field?

唔係好明添 你係覺得邊緣像差冇改善? 我唔係好識睇.

呢個 "flat field" 其實應該係 "field curvature"

哦~ 明了thanks! 不過幾千蚊貨仔都唔敢太高期望, 暫時我都幾滿意呢鏡的表現. (唔滿意都唔得.... $$$$)
我反而想比較一下冇ACF的meade 8" SCT 的coma error有幾大分別, 今日晏d搵搵

[Wah!!]

下次過來我家比較下囉~

[Nosneb]

下次過來我家比較下囉~

好好~~ 不如你帶來ptc玩下丫

[Nosneb]

好有趣, 0個朝(22早上)用meade8試拍對焦時比我拍到架飛機飛過.

[anguslau]

Very good! I think what you need is longer sub-exposures and more frames. Did you image at f/10? Autoguiding at 2000mm is going to be quite a challenge... [推眼鏡]

[anyone]

咁都比你拍到，勁！

[Subaru]

雖然係ACF, 但係第二張M27見到佢未做到 Flat field?

唔係好明添 你係覺得邊緣像差冇改善? 我唔係好識睇.

呢個 "flat field" 其實應該係 "field curvature"

哦~ 明了thanks! 不過幾千蚊貨仔都唔敢太高期望, 暫時我都幾滿意呢鏡的表現. (唔滿意都唔得.... $$$$)
我反而想比較一下冇ACF的meade 8" SCT 的coma error有幾大分別, 今日晏d搵搵

ACF係reduced coma但無reduce field curvature.

要Flat field SCT就要留意吓Celestron新出果隻EdgeHD.

[Nosneb]

Very good! I think what you need is longer sub-exposures and more frames. Did you image at f/10? Autoguiding at 2000mm is going to be quite a challenge... [推眼鏡]

thanks a lot Angus, yes the images for m27, m31 & m57 were taken with f/10 2000mm.

咁都比你拍到，勁！

哈哈~~ 只係咁0岩得咁橋吧 不過幾有趣