Hi,
The online print shop needs 300 DPI, not 96 DPI, and they don't want PPI.
Terminology can be muddled sometimes!
PPI usually refers to the resolution at the time of printing: the inch size divided by the pixel size.
DPI, dots per inch is sometimes used to mean the same thing but when referring to a particular printer refers to the spry pattern of the nozzles and is is usually much higher than the print ppi.
The pixel size (PPI) of both files is 4950 x 3510. 4590/16.5" = 300ppi
That is what is required, despite the print supplier using "dpi".
However the DPI as reported by windows is 96 and 300
I would not rely on that but check by dividing pixels by inches.
If you have 2 different pixels sizes for print optimised and web optimised then you must have used 2 different PPI settings in the print to File dialogue.
They are different sizes too: 2.65 MB for the 300 DPI and 5.15 MB for the 96 DPI web optimized photo.
But what is the pixel size, same or different? If the same then a different jpeg quality was used.
I have double checked this here and wherever the dot is placed in the dialogue, I get identical images, same pixel size and just a modest difference in file size due to one having print sharpening which makes a larger file (+ 14%).
The differences between images for Online Printing and Monitor/Web are:
Online: print sharpening
Web: no print sharpening
Online: specify any printer icc profile to embed
Web: sRGB profile only
Perhaps there is a bug in the software
QU is behaving perfectly here. I suppose it is possible that the demo version has a problem but Print to File is a long established feature and no-one else has reported problems.
Terry