A 4x5 wet collodion image taken through an Industar 11M 300mm f/9 at f/16
The same image with a macro shot of a section of the plate overlaid.
That macro section, and below a further digital crop.
The section of the plate that the macro shot takes up represents about 2.5% of the whole plate, and that section has about equal detail to what a 24 megapixel image contains. Extrapolating up gives this 4x5 plate a resolution just below 1 gigapixel (1000 megapixels).