1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Pixels

Discussion in 'Digital Image Editing & Printing' started by RobertCoombes, Jun 4, 2019.

  1. RobertCoombes

    RobertCoombes Well-Known Member

    My photo printer prints at 300 dpi, as do most domestic models. No matter what density of image that I throw at it, it still prints at 300 dpi. I understand that for top quality the image density should match the print density.
    My original dslr is a Nikon D70; a 6 mp sensor; 3008 x 2000 pixels. At 300dpi thats 254.7 mm x 169.3 mm. Printed on an A4 sheet gives borders of 21.2 mm and 20.3 mm.

    My D90 produces similar proportions on A3. I am not going to upgrade.
     
  2. PeteRob

    PeteRob Well-Known Member

    The printer will give best results if it can fulfil its task using a multiple of its native resolution which is 300 for Canon and something different for Epson, I forget the number. It is generally advised to round up to this figure (or multiple thereof) by resizing the image. I print from Lightroom and it does this automatically once I have laid the image out on the designated paper size and set my borders it tells me what the actual ppi are, I then set the switch to print with the image upsized (or downsampled) to a specified ppi (300, 600 .. ) accordingly. I've not seen a negative effect of downsampling a big image to 300 ppi , e.g. a 6x4 print from my 5Ds. The printers themselves lay down ink at a very much higher density and precision than 300 dpi, several thousand. I would think the base ppi/dpi figure is related to optimisation of the print head movements across the page and the paper transport through the printer lengthways. If the head is moving to cover integer multiples of its basic "mobility" lets call it then this probably gives the fastest and most even ink coverage.

    As you point out, for acceptable small prints you don't need that many MP in a camera. Resizing for printing was a big issue when cameras were 3 MP. Now you hardly ever hear about upsizing and sharpening for printing which was part and parcel of making images with interpolated pixels more credible.
     

Share This Page