Think pixels, Shel. 5:7 is a proportion, not a dimension like 5x7.
To make a 10x14" image area (5:7 proportion) on paper at 330 pixels
per inch, you need 3300x4620 pixels. That's 15+ Mpixels, greater than
the DS sensor produces and generally more than you need for a quality
print to that size.
To make a 10x14" print using the 2000x3000 pixels available without
upsampling, you need to print at 200 ppi. This will print an image of
2000x2800 pixels: the crop means you are losing a 200 pixel wide
strip off the long dimension.
If you WANT to print at 330 ppi and make that size print, you need to
upsample the DS image file to expand the number of pixels by a factor
of 1.65x linearly. The result, if done correctly, should look
indistinguishably different from printing at 200 ppi if done well,
but might look a little better if processing after the upsampling was
done properly.
Godfrey
On Oct 22, 2005, at 8:24 AM, Shel Belinkoff wrote:
No no no ... i wasn't talking about printing 5x7, but of using a
5x7 format
crop but printing 10x14 or so. Will read more and comment further.
Shel
[Original Message]
From: Godfrey DiGiorgi
Depending upon how you upsample and edit the image, it can be used to
advantage to make large sized prints with higher quality ... but is
completely unnecessary to print photos in the 5x7 inch image size
range from a 6Mpixel camera. I upsample image files when I'm
intending to print to 13x19 inch, or larger, image area sizing in
order to get more cropping room to work with, or to meet the needs of
a particular printer device.
