昇仔攝星集：湯博士在 21/5《今日 VIP》節目分享他的天文照片和攝影經驗

[昇仔]

30/11/2013 與學生去觀星營拍的獵戶座大星雲、巴納德環
450D modified EF 85 mm F/1.8 @ F/2.8
11x6 min Vixen SXD Astronomik CLS
西貢麥理浩夫人度假村
趁學生已都睡了覺的時隨意拍的，那天等 Lovejoy 出來沒有睡覺。

[littleming]

[noodle]

睇唔睇到 Lovejoy 、 ison ?

[anyone]

隨手拍都咁靚。真汗顏了 !

[LT]

With our so poor sky conditions in HK, that is very fabulous indeed.

For this 85mm lens, it is better to step it down to F4 or even slower. @F2.8, the star image at the corner is still not good.

Just my $0.02.

LT

[davidc129]

Beautiful!

[昇仔]

睇唔睇到 Lovejoy 、 ison ?

失踪十日回來了

其實果影到天光先剛剛睇到 Lovejoy, 係咁二都影到下。
ISON 就死左啦

[昇仔]

With our so poor sky conditions in HK, that is very fabulous indeed.

For this 85mm lens, it is better to step it down to F4 or even slower. @F2.8, the star image at the corner is still not good.

Just my $0.02.

LT

LT,

Yes as you say, F4 would give better stars at the corner, I just wonder if is too slow to take an image with F4 in the light polluted sky.

[bingsze]

你果句「隨手拍」真係好頂癮！

[Carl Chan]

昇爺，正！麥村個環境都影到靚！

[bingsze]

等緊你張『係咁二』！

[LT]

LT,

Yes as you say, F4 would give better stars at the corner, I just wonder if is too slow to take an image with F4 in the light polluted sky.

If temperature is low enough, I think better result will come out as the S/N of RAW image is a bit better @F4.

LT

[昇仔]

昇爺，正！麥村個環境都影到靚！

謝謝！

[昇仔]

Why does a larger f-value produce a better S/N? I thought the photon noise would be larger.

LT,

Yes as you say, F4 would give better stars at the corner, I just wonder if is too slow to take an image with F4 in the light polluted sky.

If temperature is low enough, I think better result will come out as the S/N of RAW image is a bit better @F4.

LT

[wtyu21]

等緊你張『係咁二』！

X2