Canon 一問??

當然是IXUS 850 IS好啦,多咗個防震對低光或者長焦距時手持幫助很大,分分鐘係清晰用矇既分別.
不過唔好意思要撥你冷水,如果你諗住手持影夜景單單靠個防震係唔會好理想的.因為快門實在太慢,一般室內燈光還可以.始終都係要用翻腳架.
至於用機仔影演唱會不要抱任何期望,除非你可以走埋個歌星前面用閃光燈影,否則zoom到盡都唔夠大,光圈又變細,高iso又多noise,閃燈又唔夠火力.防震都幫唔到你,一來放唔到咁多級,二來歌星走來走去要大光圈,高iso先有用.除非你諗住影下個場就得.

兩部機影相當然清楚啦 .

影夜景就 IXUS 850 IS 好啲 , 因為有光學防手震 ; IXUS 75 要用腳架先影得清 .
演唱會方面 , 如果你坐在前排而且不太暗的話 , IXUS 850 IS 無大問題 ; 別考慮IXUS 75 了 .

如果想影演唱會 , 可考慮Canon PowerShot S3 IS
雖然它只有600萬像素和DIGIC II , 但它有12倍光學變焦 , 即使坐得遠啲都可以影到 ; 有光學防手震 ; 光圈在遠攝時仍比較大(F3.5) ; 用電子取景器+機身比較易揸穩 , 而且有扭Mon, 是DC中最適合影演唱會的選擇之一 .

IXUS 75 (SD 750) and IXUS 850 IS (SD 850 IS) share many of the components/features such as sensor and image processor . The major differences are:

Lens
75: 35 -105mm (35mm equivalent), F2.8-4.9
850 IS: 28 - 105mm (35mm equivalent), F2.8 - 5.8

Image Stabilizer
75: No
850 IS: Yes

LCD
75: 3.0-inch P-Si TFT, 230,000 pixels
850 IS: 2.5-inch P-Si TFT, 207,000 pixels

Both of them take very good pictures. However, 850 IS has the advantage in dim environment because of the Image Stabilizer. Use the shooting mode wisely to get better picture quality. For instance, switch to "Night snapshot" mode for night shoot or concert. Also, 28mm wide-angle is a plus when shooting landscape or group photo.

I'd recommend IXUS 850 IS!