I have a new A3+ printer and was wondering how I could print out selected parts of the image on an A4 sheet (essentially a contact sheet) to check sharpness, colour rendition etc before committing to printing a full A3 version. Obviously I would like to have the section(s) printed on A4 at the same physical size as they would appear when printed on the A3 sheet.
Is there an easy way to do this through Lightroom? Or do I need to go through calculations of DPI, printer resolution etc?