[freedots]

會員戶口已被刪除，資料已被標示為不顯示

[老叟]

肉眼睇就根本睇唔出有咩分別!!

[Philippe]

街外晒相係用300dpi
3R 3.5”x 5”要 1050x1500
4R 4”x 6”要 1200x1800
5R 5”x 7”要 1500x2100
8R 8”x 10”要 2400x3000
12R 8”x 12”要 2400x3600

[6x4.5]

大錯特錯
請注意dpi與ppi並無直接關係

[Philippe]

是嗎?請指教

[6x4.5]

The image whichhas been recorded digitally by digital camera is just a grid of pixels a certain number of pixels high by a certain number of pixels wide. (eg: 1024x768)

When printing, ppi/dpi resolution has a different meaning.

If you print the image, something must tell the printer what ppi resolution to print at. The pixels-per-inch resolution that an image is set to print at is the "print resolution" (or output resolution). This resolution is usually referred to in terms of dpi, is an attribute of the image file itself, and you can change it to whatever you lke in Photoshop or other software without affecting the image itself.

Adjusting an image's resolution in dpi has no effect on the actual pixels. The image remains the same grid of pixels with the same pixel dimensions and pixel data. The effects of such adjustments or settings are only seen in and only apply to the printing of the image, and there is no rule that how many ppi is one dpi, or the way round.

[6x4.5]

The pixel to dot correlation for a printer is simple and is much more dependent on the software.

Most DCs are optimized for monitor viewing, which is 72ppi. If a 640x480 image is printed at it's full 8.9x6.7 inches on a 360 DPI printer, the printer has to print 5x5 dots for every pixel (360 / 72 = 5). The result is no good when viewed closely.

If the image can be printed smaller, the 72 PPI of the file can be compressed to a denser DPI value on the output eliminating the grainy results. Unfortunately, if it is compressed to 360 DPI, the image is 5 times smaller, only 1.8x1.3 inches. Intermediate values, such as 144 DPI (4.4x3.3 inches) often give good results.

Larger image files give better looking bigger prints. A 1280x1024 ppi file, will make a very good 3.5x2.8 inch 360 DPI print. 1800x1440 ppi gives 5x4 inches at 360 DPI.

[Toilet_Paper]

In general, assuming the DC is capable of producing good sharp results, 3MP is ok for 5R. However, the actual print size depends on how many dpi the printer is using. For instance, for Epson printer which has 5760 x 1440dpi, the optimal ppi set for the picture file should be 360, but it can also be set to 288 or 240 depends on your expectation on the final output. Higher ppi setting will result in higher quality prints.

For a 3MP picture (1536x2048), the print size will be:
360ppi: 4.2x5.68"
288ppi: 5.3x7.1"
240ppi: 6.4x8.3"

For a 4MP picture (1704x2272), the print size will be:
360ppi: 4x7x6.3"
288ppi: 5.9x7.9"
240ppi: 7.1x9.4"

[6x4.5]

Wrong typing:
The pixel to dot correlation for a printer is NOT simple and is much more dependent on the software.

[Philippe]

我大概都明你講乜啦.不過我假設freedots網友係攞出街晒相,唔係自己用printer 印相的話. 咁300 dpi係冇得自己設定的. 咁我計算上唔會大錯特錯呱.

[6x4.5]

語氣激左小小
sorry~

[technok]

三、四百萬像素有時候並不足夠, 如果 影 bb 相, 要小小燈光技巧! 0米先 bb 會無"下巴", 好恐怖價!

[freedots]

會員戶口已被刪除，資料已被標示為不顯示

[Toilet_Paper]

It is pretty safe to use 300ppi for calcutaion if they will be printed by labs.

[mini_mashimaro]

咁出面街係咪全部用300dpi?
thx^^