August 17, 2017, 10:13:00 AM

Author Topic: Printing quality paremeters enquiry  (Read 628 times)

ironfreak

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Printing quality paremeters enquiry
« on: July 26, 2017, 06:03:36 AM »
I want to sell few images for a client and they will print. I have a simple question for images clicked from Canon 6D:

I am setting up best possible parameters in Photoshop.

Which is better for printing?

1) 5472 x 3648
   
    72 ppi
   
    76 x 50.667 inches

2) 5472 x 3648
   
    300 ppi (unchecked resample)
   
    18.24 x 12.16 inches

a) Which one of these two is better for printing?
b) If I do resample for 300 ppi then pixels increase to 22800 x 15200. This is too much heavy file. But document size in inches remains same. I presume this is not ideal method. Is it?

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Printing quality paremeters enquiry
« on: July 26, 2017, 06:03:36 AM »

LDS

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Re: Printing quality paremeters enquiry
« Reply #1 on: July 26, 2017, 07:00:41 AM »
As long as the pixel count doesn't change, the resolution is just an image "tag", an hint to compute the "physical" size at that resolution. So 5472 x 3648 at 72ppi or 300ppi is the same image in a file, until you print it at a given resolution, that can be different from whatever is set in the file.

Usually the print resolution is selected taking into account the printing technology, print size, viewing distance, and pixels count of the original image, and the image resampled accordingly. Downsampling is usually OK, upsampling usually introduce issues, but for smaller values. Thereby the more the native pixels, the larger the image can be printed at higher resolutions - and thereby viewed closer. There are formulas available, which take into account the human eye resolution.

72 ppi is usually too low, but for larger images seen far away. Most inkjets prints are printed at around 300/360ppi, some higher res one at 600/720 (Canon/Epson native resolutions), some larger ones may use lower resolution (240, 150, as needed). Image printed using different technologies may use other values.

For that reason, the resampling is usually made by the print process itself, when all the needed parameters are known. If you know them exactly in advance, you may perform all the steps yourself (if really needed for specific reasons), otherwise you may make a resample and your customer another - and it will just mean a degraded quality.

Thereby, give your customers an image with a pixel size large enough for their print size without upsampling, the image file resolution is not important.
« Last Edit: July 26, 2017, 02:40:24 PM by LDS »

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Re: Printing quality paremeters enquiry
« Reply #1 on: July 26, 2017, 07:00:41 AM »