Due to the fact that the correct sharpness not seen at all zooming options photos, especially on laptops monitors, it would like to make settings % when opening photos in default zoomed. This is to accelerate the process works!
Though I haven't tried, I would think zoom scales where the on-screen pixel dimensions are multiples of 2 or maybe 4 of the pixel dimensions at 100% would be the most accurate. That way you are not splitting half-pixels, even though you are still interpolating...
Makes sense in my head, but I don't know how well that translates to real-world use.