New Horizon Cameras Options

[Guest_vjkane2000_*]

I've been wondering what the focal lengths are for the two New Horizon cameras (Ralph and Lorri). Curious to know how much Alan et al. were able to squeeze into their weight budget.

[Xcalibrator]

2) The best possible AR coatings are used.

I heard a recent talk (abstract) (video here) by Roberto Abraham (U. Toronto) about Dragonfly, "a robotic imaging system optimized for the detection of extended ultra low surface brightness structures." A key technology was the anti-reflection coating developed by Canon which lets Dragonfly go a couple/few magnitudes deeper on extended sources than conventional telescopes. Their "coating" is actually nanostructured tapers/wedges that provide a continuously varying index of refraction so there are essentially no reflections. I'm not sure how useful this would be for cameras on planetary missions but it's pretty cool. Canon is keeping the details to themselves but a quickie search found some info here and here.

[Brian Swift]

Just came across a 1/2021 (open access) paper that goes into a bit of detail about various LORRI low light level imaging biases and methodology to remove them.
New Horizons Observations of the Cosmic Optical Background

Also, NASA PR page about result https://www.nasa.gov/feature/new-horizons-s...w-dark-is-space