Re: Analisi foto lunari 2
Inviato da doktorenko il 13/10/2009 18:59:11
Citazione:
Ho trovato questa faq lunare su WikiAnswers:
http://wiki.answers.com/Q/Did_man_really_land_on_the_moon
There are several photographs of objects that are in shadows, yet they appear lighted and with surprising detail. Objects located in shadows should appear totally black.
The problem with this statement is that it fails to consider reflected sunlight. Next to the Sun, the largest source of light on the Moon is the lunar surface itself, which reflects large amounts of sunlight. At the Earth-Sun distance, maximum solar illumination is about 10,000 lumens per square foot; however, if the Sun is not directly overhead its rays will strike the surface obliquely. This decreases the intensity of sunlight per unit area. A typical Sun elevation during the Apollo landings was about 20 degrees, thus the illumination per square foot was about 3,400 lumens. Since the Moon's surface reflects about 10% of the light it receives, each square foot of surface reflected about 340 lumens. This is equivalent to the luminosity of a 35-watt light bulb. This amount of light easily explains the illumination observed in the Apollo photographs.
Parla di 340 lm/ft2 cioè circa un decimo di un metro quadro, sarebbero 3400 lm/m2 con 20° di elevazione e 100.000 lm solari, io ho calcolato 3500 lm/m2 con 130.000/140.000 lm dal Sole e 15°.
Tuttle ha scritto:
Citazione:In questi dati però si calcola solo la quantità di luce incidente sulla superficie, bisonga poi aggiustarli secondo percentuale di riflessione del materiale, qui è come se fosse il 100%.
Si ma a noi interessa capire quanta luce arriva sulla luna. I poteri di scattering dei vari materiali in gioco andrebbero calcolati in maniera più articolata rispetto al semplice taglio dovuto all'albedo.
Io credo che la chiave di lettura sia anche questa. Cioè, secondo me, in gioco c'è proprio la quantità di luce in arrivo sulla luna, le performance di scattering e backscattering del terreno e i materiali delle tute.
E' una pista eh...non voglio dire che sia quella giusta.
Ho trovato questa faq lunare su WikiAnswers:
http://wiki.answers.com/Q/Did_man_really_land_on_the_moon
There are several photographs of objects that are in shadows, yet they appear lighted and with surprising detail. Objects located in shadows should appear totally black.
The problem with this statement is that it fails to consider reflected sunlight. Next to the Sun, the largest source of light on the Moon is the lunar surface itself, which reflects large amounts of sunlight. At the Earth-Sun distance, maximum solar illumination is about 10,000 lumens per square foot; however, if the Sun is not directly overhead its rays will strike the surface obliquely. This decreases the intensity of sunlight per unit area. A typical Sun elevation during the Apollo landings was about 20 degrees, thus the illumination per square foot was about 3,400 lumens. Since the Moon's surface reflects about 10% of the light it receives, each square foot of surface reflected about 340 lumens. This is equivalent to the luminosity of a 35-watt light bulb. This amount of light easily explains the illumination observed in the Apollo photographs.
Parla di 340 lm/ft2 cioè circa un decimo di un metro quadro, sarebbero 3400 lm/m2 con 20° di elevazione e 100.000 lm solari, io ho calcolato 3500 lm/m2 con 130.000/140.000 lm dal Sole e 15°.
Messaggio orinale: https://old.luogocomune.net/site/newbb/viewtopic.php?forum=13&topic_id=970&post_id=148159