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1. Re: Photoshop CS6: Why is ACR set to 240 ppi by default, and not 300 ppi?
Samoreen Jun 13, 2013 5:22 AM (in response to Page D)Hi,
Setting this value to 240, 300 or whatever else will not change anything. The TIF or JPEG file generated from the RAW file will just have a metadata field containing this value (actually, there are 2 fields : XResolution and YResolution, usually set to the same value). The rest of the file will remain unchanged. Two files generated from the same RAW one at 240 dpi and the other at 300 dpi will only differ by that field.
When you load the file in PS (or when ACR transmits a raw image to the PS bitmap engine along with its metadata), the dpi value found in the metadata will only affect the default values that will be used in the File | Print dialog, Position and Size section. By default, PS will compute the printed size of the document according to the indication given in the XResolution/YResolution field. If you change the desired dimension or if you "scale to fit", the dpi resolution will change.
The dpi value specified in ACR or in any other software is only an indication. It never affects the image itself. Actually, this dpi value has no meaning until the image is "realized". A dpi value only makes sense when the pixel are transformed into ink dots in a printer or to display pixels on a screen. Until then, this value has no meaning.
Moreover, in Lightroom (which makes printing much more easy than in PS), it is actually recommended to not specify any dpi value. That field should usually be left blank. You specify the print target dimensions and LR will automatically compute the right dpi value.
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2. Re: Photoshop CS6: Why is ACR set to 240 ppi by default, and not 300 ppi?
uk kazman Sep 24, 2013 3:31 AM (in response to Page D)My print collegues are always being told by printers that then need 300dpi. It is just a box ticking exersize, however if you save to 300dpi you do not need to have the same arguement with everyone.
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3. Re: Photoshop CS6: Why is ACR set to 240 ppi by default, and not 300 ppi?
PECourtejoie Sep 24, 2013 5:34 AM (in response to uk kazman)Hello!
It was indeed the old rule of thumb in the print industry, when printing on an offset printer, to at least use the 300PPI resolution to avoid artifact due to the sub-dots that would make each pixel.
But, for inkjet printers, much more common, it was often recommended to use a fraction of the printer resolution, and 240 fits the bill for the 720, 1440, 2400 and 2880PPI printers.
I think that more photographers output to an inkjet than on a press, so that might explain why such a setting was chosen, but can easily be reconfigured.
And also, it will all depend how large you are printing your image.



