I know it seems useless setting the resolution on this particular dialog, it’s just a habit I have got into.
I’ve just always used 72ppi for screen display, even though my present Apple Display is around 110ppi.
The only time resolution is critical is when sending a file to a printer, where it determines the physical print area. It is a common misapprehension that this should be 300ppi, but this comes from people thinking that it needs to match the printer resolution, whereas, for viewing at the average distance, you only really need 240ppi.
And thereby hangs another misconception…
On this dialog DxO has, erroneously, used dpi as the unit when this should only ever apply to the resolution of the dots on paper from the printer, not the number of pixels, each one of which may be printed with several ink dots.
My Epson SC-P600 can print up to 5760dpi which, if each dot equalled one pixel, would give a print size of less than an inch for an image from my Nikon D810. As it is, 7360 pixels for the long edge of one of my files gives me a length of 30.67 inches.
When I am printing for our photo club’s exhibition, the frames are all 50cm x 40 cm, so I have a spreadsheet that calculates what finished image size I need at 240ppi to fit inside a matboard that gives a margin of 6cm at the narrowest (it’s all about proportion and aesthetic). Then I just take the number of pixels for the longest side and either export the image as TIFF, for printing through ColorSync, or I print direct from PhotoLab using the physical dimensions from the spreadsheet.
Interesting article if it didn’t insist on erroneously propagating the myths I have just discussed, in mixing up the concepts of dpi and ppi