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Title: Job Properties: PPI or DPI? Post by: Mack on September 10, 2011, 06:57:24 PM I noticed in "Job Properties" the settings for 'Resolution' are in PPI (i.e. 607 PPI, 303 PPI, 202 PPI, etc.). Shouldn't that be DPI and not PPI? ???
Thought PPI was "Pixels Per Inch" for camera sensors, unless it is something else in printer speak where they are DPI (or "Dots Per Inch"). Sort of very odd numbers too (607, 303, 202, 151 PPI) unless that is the true printer resolution? Mack Title: Re: Job Properties: PPI or DPI? Post by: Fred A on September 10, 2011, 07:11:19 PM Mack,
Mike wrote a good article http://ddisoftware.com/tech/articles/january-2005-coming-to-terms-with-dpi-ppi-and-size/msg12/#msg12 Read that over a couple of times. The numbers you quote seem odd unless you are using borderless or scaling in the driver. Or you are quoting the ppi of the print about to be printed. What printer model is it? The ppi refers to the input to the printer See screen snaps. Where are you reading your ppi? Fred DPI refers to the output pf the printer to the paper in the finest sprays from the nozzles. Title: Re: Job Properties: PPI or DPI? Post by: Terry-M on September 10, 2011, 07:16:18 PM Hi Mack,
PPI in strict terms only applies to a visible image, either on screen or a print. An image on it's own, in reality does not anything "per inch", just pixels. Cameras and some software does tag images with a ppi but it's a notional number. DPI refers to the printer Dots or spray pattern of the printer head and these days can up to numbers in 1000's. However, a printer has a "Native" resolution, typically for Epson 720ppi, HP & Canon 600ppi. THE clever feature of Qimage is that it it sends the image to the printer at that print resolution, interpolated by Mike's superior algorithms, so the printer driver does not have to mess around with the pixels at all, hence the excellent prints from Qimage. See http://www.ddisoftware.com/qimage-u/tech-prt.htm Quote Sort of very odd numbers too (607, 303, 202, 151 PPI) unless that is the true printer resolution? Yes it is but they are odd numbers because you have borderless set in the driver - Qimage reports these numbers from the driver. When in borderless mode, the driver expands the print area by increasing the PPI.See the Learning Video that covers this: http://www.youtube.com/watch_popup?v=gMzUxDP_JwM&vq=hd720 Terry PS. Fred beat me to it but our answers are complimentary :) Title: Re: Job Properties: PPI or DPI? Post by: Fred A on September 10, 2011, 07:49:56 PM Quote PS. Fred beat me to it but our answers are complimentary Yes, I am Fast Freddie! But I turn you over to the capable hands of Terry the Tutor. I have to go out for some supper. Fred Title: Re: Job Properties: PPI or DPI? Post by: Jeff on September 11, 2011, 07:12:48 AM Oh - don't stir up the question of dpi
Local camera club absolutely insists that web/projection images are at 72dpi and there are give extensive instructions on creating a image at 72dpi. 1074 x 768. They cannot/will not accept that I just click create web/email image and select what I would call a screen size and job is done. Best of it is that having got the image at 1074x768 they then re size down again to fit their web page. jeff Title: Re: Job Properties: PPI or DPI? Post by: Terry-M on September 11, 2011, 12:38:25 PM Quote Oh - don't stir up the question of dpi Unfortunately many photographers get confused on this matter. :(It helps to refer to PPI for images when they are changed into a viewable form, screen or print and DPI only for printers and their spray pattern. The language matters. ::) Terry |