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fluffy
21st April 2008, 02:13 AM
I have to be missing something very obvious. Sometimes I think that's my career.

Every Olympus camera I own - 2 DSLR (and a 330 on the way!) and 2 P&S) records its best quality JPEGs at 314 ppi, or at least that's what PhotoShop (and PSE and LR) says. 314? Not divisble by 3, indeed, maybe only by 2 although I suspect other values. My HP printer prefers images to be 300 ppi for best quality prints and I believe Epson likes 240. Is there something I'm missing related to ppi and dpi (I know they're different sometimes)?

I've created a simple action to down res my Oly files to 300 ppi using Genuine Fractals 5 (highly highly recommended) so it's no big deal, but it bothers me.

Any setting me straight greatly appreciated.

Chrs, Stv

RogerMac
21st April 2008, 04:15 AM
It prints out directly at A4 without further scaling (thats with images from an E510)

mikefellh
21st April 2008, 04:33 AM
The DPI or PPI that an image is set to only matters when you print, and it tells the printer how many pixels from the image to put in one inch of paper.

For instance if I made a 72x72 pixel image and I set it to 72ppi, it will (or should) print in a 1 inch square. If I print it at 36ppi, it will print a 2 inch square, and at 144ppi it will print in a 1/2 inch square.

In the old days 72ppi was always used because that's what old computers used, my C-700 still used that for a default PPI, but the ppi an image is set to is meaningless, UNTIL you go to print.

You didn't say which Olympus you currently own, but since you mentioned the E-330 let's look at that...it's maximum resolution is 3136x2352...at 314ppi it will produce (roughly) a 10"x7.5" image (without cropping). At 300ppi it will produce a 10.45"x7.84" print. If you want a smaller image you print at 522ppi for a 6"x4.5" image.

The PPI sets the size in inches. 314 was chosen as a default because they wanted to make it easy as pie (get it, pi being 3.14)...many people still only have letter sized printers, so if they printed it themselves it would fit into an 10x8 frame without cropping, and the white borders on the 8" side isn't that bad if you use a white mat.

Printers don't care about this number since you are telling it what to do, how many pixels from the image fit onto one inch of paper...whether it is 300 or 314 won't make a difference (other than printed image size). 300 is only a suggested number by the manufacturer, and personally I don't read the directions (but I've been printing digital images for over 15 years).

The Genuine Fractals step is wasted and is physically altering pixels, which is a BAD thing, although GF is a good program for printing larger images from a 2mp image, or say a high resolution billboard sized image from an 8mp.

fluffy
21st April 2008, 07:47 AM
Thanks Mike and RogerMac. I was worrying for nothing. And my workflow will now speed up.

Chrs, Stv

dbutch
21st April 2008, 12:15 PM
Hi

If memory serves me right the Olympus Dye-subs have a resolution of 314 dpi and that was why the cameras had it as a defualt

Cheers

Dave

Paul
21st April 2008, 01:09 PM
Hi

If memory serves me right the Olympus Dye-subs have a resolution of 314 dpi and that was why the cameras had it as a defualt

Cheers

Dave

Correct! :)