Thanks for that. I accept now that the Apollo video camera used an image intensifier SEC tube which is capable of low light operation. But you didn't quote this from the same page of your linked report: "Since there were no other device [sic] that could possibly meet the Apollo TV camera mission requirement to operate unattended at both lunar day and lunar night and survive all phases of the Apollo mission, the DOD was asked to allow Westinghouse to use the SEC tube for the Apollo TV camera program." (My emphasis). In other words the low light capability was driven by the requirement to operate the camera during the lunar night, and is therefore no evidence that light levels during the lunar day were expected to be low. You have either carelessly missed this point, or you have knowingly and dishonestly hidden it from readers of the forum to mistakenly give the impression that the choice of Apollo video camera technology is evidence for light levels lower on the lunar surface than conventionally expected.GaryN wrote: ↑Mon Nov 09, 2020 8:37 pmHiggsy wrote:First of all you give absolutely no reference or evidence for your assertion that Apollo video cameras were low light devices or that NASA had to go to the DoD to use them.Early in the Apollo program NASA became aware of a special low-light television imaging tube that Westinghouse had developed for the Department of Defense. Due to the war in Viet Nam, the Army was developing low light devices for use as jungle surveillance devices and on aircraft to spot a downed pilot at night. To meet the DOD requirements Westinghouse developed a sensitive image tube that combined a variable-gain light intensifier with a secondary electron conduction (SEC) target. The SEC tube had the capability to reproduce objects in motion, at low light levels, without the normal smearing produced by vidicon or image orthicon tubes.
https://www.hq.nasa.gov/alsj/ApolloTV-Acrobat5.pdf
In checking various documents referenced in the report above, the day lens has an equivalent f-number of f/60 and the night lens of f/1.15 (including ND filters). The night lens is therefore approximately 11 stops or 2,700 times brighter ((60/1.15)^2) than the day lens, which can be compared with the maximum scene brightness in the specifications of the camera of 12,600 ft-lamberts (43,000 lux) for the day, and 5 ft-lamberts (17 lux) for the night (a ratio of 2,520). See page 51 of https://www.hq.nasa.gov/office/pao/Hist ... 3-1968.pdf. Yet again the actual evidence does not in any way support your idea.