<p>Most of the responses are (not surprisingly) from a photographers point of view. Bill Lynch identified the engineering constraints that govern many scanners. My Kodak 3570 scanner never competed with drum scanners, but it was considered a pretty good scanner for 35mm and medium format in its day (20 years ago). The maximum image it could handle was 2048x3072. Whether you were scanning 35mm or medium format, there was no way to squeeze more than 6,291,456 pixels out of it. For 35mm the image was 2048x3072. For 120 square format the images were 2048x2048. For 6cmx4.5cm negs, the image was 2048x2730. For 616 format negatives (2.75 in x 4.25 in) I cut a larger hole in the negative carrier and used the maximum reduction setting to squeeze in the extra image size. The resulting images were 1988x3072. <br>
The full size version of this image is 1895x3264. It is a combination of two 616 size negatives. (Shot with Kodak Vigilant 616 camera in 1966). <br>
<img src="https://photos.smugmug.com/photos/i-CXVXdzw/0/M/i-CXVXdzw-M.jpg" alt="" /></p>