we have bought a 13 mp 5 mp cameras smartphone, leagoo alfa 2, from aliexpress, i have tested it, and discovered that it probably has 8 and 2 mp cameras. i have made photos with different image file size, and zoomed photos, and looked, whether detailedness increase with increased files size. you can see my test photos in http://qdb.tmf.org.ru/leagoo%20alfa%202%20cameras%20test/ .
i attach them here too, in blog post, and you can download original photos from the above link:
test of main (rear) camera:
– i see that there are no more new details after 8 mp.
test of front camera:
– i see that there are no more new details after 2 mp.