[kevin-lo]

請問各位CHING有無用PHOTOCAP 加相框及公仔? 是否存后SIZE細左及RESOLUTION低左好多?

我已經用3600DPI存檔 (原本自動300DPI), 但都係. 是否有什麼做錯?請指教.

[nofeel]

因為用jpeg save會lose quality. 每save一次lose一次. 所以點解要用raw.

[王迦南]

除非你自行修改，否則執相後解像度(resolution)不會改變。

dpi(dots per inch)是點密度，300dpi存成3600dpi，點密度高了，照片尺寸自然會縮小，但解像度卻沒有改變。

解像度 = (點密度 x 長) x (點密度 x 高)

[vdo]

我都想知，thank you very much南哥。

[klchan23]

DPI is for printer. More DPI means better color. Therefore, when you change it, it will not change anything on your monitor.
Because the resolution will be the same. Because the PPI is the same. In most monitor, it only support 300PPI.

Moreover, most high-level printer will support only 2880 x 1440 dpi. There is no reason to set your DPI to 3600DPI.

When you refer to change of resolution. What are you about talking? Is it in printing or in monitor display?

[ncychan]

因為用jpeg save會lose quality. 每save一次lose一次. 所以點解要用raw. Agreed x 1

除非你自行修改，否則執相後解像度(resolution)不會改變。
Agreed x 1.

But since JPEG is a compression format, each time even you just edit a pixel, not matter you keep the same resolution of the whole picutre, your picture quality (detail, hue and saturation, color accuracy and gray level) will be affected because this single pixel will can cause the variation of the pixels surrounding it.

That's why ppl edit photos using RAW format because all the data are RAW ( 原始圖象數據存儲格式 without compression) . As each pixel has its own individual data code, it cannot be affected by the other pixel. That's the best way to fine tune pictures without the side effect of JPEG compression.

( Hope it can help. )