When what you’re after is very high resolution, film still scales better than digital; the largest (somewhat common) film format is 8x10».
A sheet of slow (fine grain) film at this size can capture detail way beyond what any digital sensor I know of - surely it can be scanned with the equivalent of multi-gigapixel resolution - and if one were to develop such a monster sensor, it would have a hard time competing with the film in all but a few edge cases. (Most notably the ability to transmit imagery to the ground immediately, provided the necessary bandwidth is available.)
Film alone doesn't determine performance - the whole instrument must be considered. The OBC trades "resolution" for area coverage rate. The digital electro-optical imagery from the U-2 is produced using an instrument (SYERS-2) with a different optical design. Intelligence Imagery (IMINT) is rated on the NIIRS scale and the OBC imagery is most-likely unclassified now due to it being at the mid-range of the NIIRS scale.
You make a good point about the scanning. Any wet film product these days must generally be scanned to allow for further production in our "soft-copy" world.
lb1lf|7 years ago
A sheet of slow (fine grain) film at this size can capture detail way beyond what any digital sensor I know of - surely it can be scanned with the equivalent of multi-gigapixel resolution - and if one were to develop such a monster sensor, it would have a hard time competing with the film in all but a few edge cases. (Most notably the ability to transmit imagery to the ground immediately, provided the necessary bandwidth is available.)
libertyhouse|7 years ago
You make a good point about the scanning. Any wet film product these days must generally be scanned to allow for further production in our "soft-copy" world.