I worked on one project that had a 17 ft diameter multi-faceted (with an actuator per facet) mirror that fed the super special camera elements. Now not classified, it could read a quarter from orbit. Was used on Desert Storm and see thru the dust clouds too. And I totally agree with you that the military takes way too much flack from uninformed people and especially the super ignorant media. We worked 24/7 to get that thing up in orbit in record time and saved many lives due to its capabilities way beyond what I have mentioned.

The best-performing digital camera now in production isn't a Canon -- it's a KENNON:
the KH-12 "Keyhole" (a.k.a. KH-11B, "Ikon") reconaissance satillite. KENNON was
started by the NRO in the 1970s, and renamed CRYSTAL in 1982. The latest launch was
on January 19 of this year.

How good it it? That's classified. But we know it can tell what hat you are wearing from
150 miles up.

Your Canon uses lens elements that refract light, creating aberrations that then need to be
corrected by still more elements. The KH-12 uses a first-surface mirror at least 2.4 m in
diameter.

But your Canon camera might well contain more lines of firmware than the KH-12.
Consumer products typically are loaded with "bells & whistles".

The less sharply you refract light, the less aberrations you get. But for convenience, camera FFDs
are kept very short -- often shorter than the focal lenght of the lens. So the job of the rear element
is to sharply refract the light onto the sensor.

The distance from the lens to the sensor (FFD) of your Canon is measured in millimeters:
44 mm if its an EOS DSLR and 18 mm if its a EF-M mirrorless. The FFD of the
earliest spy satillites (that used lenses and 70 mm film) was over 20 feet. The effective
focal length of the Hubble Space Telescope (not classified) is 57.6 m (about 159 feet).

All modern spy satillites and big telescopes use first-surface mirrors as the primary optical element.
A reflector is better than a refractor (that is, if you care about state-of-the-art performance.)
For one thing, it has no chromatic aberration.

Spy satillites have cryo-cooled image sensors: no noise is good noise. So do all digital
cameras used with big telescopes.

A close second to the best-performing digital camera title is NIRCam, recently complete
by Lockheed Martin for NASA's James Webb Space Telescope.
https://jwst.stsci.edu/instrumentation/nircam

If you think military procurement is irrational and prone to "boondoggles", take a look
at consumer procurement. The USAF never bought a pet rock...or a subminature
format digital camera.

There's technology, and then there's consumer technology.

The best-performing digital camera now in production isn't a Canon -- it's a KENNON:
the KH-12 "Keyhole" (a.k.a. KH-11B, "Ikon") reconaissance satillite. KENNON was
started by the NRO in the 1970s, and renamed CRYSTAL in 1982. The latest launch was
on January 19 of this year.

How good it it? That's classified. But we know it can tell what hat you are wearing from
150 miles up.

Your Canon uses lens elements that refract light, creating aberrations that then need to be
corrected by still more elements. The KH-12 uses a first-surface mirror at least 2.4 m in
diameter.

But your Canon camera might well contain more lines of firmware than the KH-12.
Consumer products typically are loaded with "bells & whistles".

The less sharply you refract light, the less aberrations you get. But for convenience, camera FFDs
are kept very short -- often shorter than the focal lenght of the lens. So the job of the rear element
is to sharply refract the light onto the sensor.

The distance from the lens to the sensor (FFD) of your Canon is measured in millimeters:
44 mm if its an EOS DSLR and 18 mm if its a EF-M mirrorless. The FFD of the
earliest spy satillites (that used lenses and 70 mm film) was over 20 feet. The effective
focal length of the Hubble Space Telescope (not classified) is 57.6 m (about 159 feet).

All modern spy satillites and big telescopes use first-surface mirrors as the primary optical element.
A reflector is better than a refractor (that is, if you care about state-of-the-art performance.)
For one thing, it has no chromatic aberration.

Spy satillites have cryo-cooled image sensors: no noise is good noise. So do all digital
cameras used with big telescopes.

A close second to the best-performing digital camera title is NIRCam, recently complete
by Lockheed Martin for NASA's James Webb Space Telescope.
https://jwst.stsci.edu/instrumentation/nircam

If you think military procurement is irrational and prone to "boondoggles", take a look
at consumer procurement. The USAF never bought a pet rock...or a subminature
format digital camera.

There's technology, and then there's consumer technology.