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Fluorescents and the Kelvin Myth
Posted:
Sat Nov 06, 2004 2:23 pmby birddog114
Posted:
Sat Nov 06, 2004 2:47 pmby Greg B
Warning - total irrelevancy follows.
Lord Kelvin was an interesting bloke......
1895 statement by Kelvin - "heavier-than-air flying machines are impossible" (Australian Institute of Physics),
1896 statement, "I have not the smallest molecule of faith in aerial navigation other than ballooning...I would not care to be a member of the Aeronautical Society."
Kelvin is also known for an address to an assemblage of physicists at the British Association for the advancement of Science in 1900 in which he stated, "There is nothing new to be discovered in physics now. All that remains is more and more precise measurement."
He invented the mirror galvanometer, a telegraph message receiver and supervised the laying of the first trans-Atlantic insulated electric telegraph cable which revolutionised world communications. He invented an electric strain gauge, an improved ship's compass, the Kelvin ampere balance and an electrostatic voltmeter amongst a host of other developments.
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I have had the pleasure of some very boozy lunches at the Kelvin Club in Melbourne courtesy of a friend who is a member.
Posted:
Sat Nov 06, 2004 3:47 pmby birddog114
Greg,
Great knowledge and wealthy information!!!!we send you to the show "who want to be a millionaire" then get the monies for lens lust
Posted:
Sat Nov 06, 2004 3:49 pmby Onyx
Interesting article link there. I had previously posted a question on another forum regarding correct WB setting for those sickly orange sodium vapour lamps. According to the article, if I wanted to take photos under those lights, I should supplement it with a full spectrum light source. However I achieve relatively acceptable results using preset WB on the D70.
Posted:
Sat Nov 06, 2004 3:57 pmby MHD
preset ballance is the way to go in those situations... as sodium lamps (and mercury lamps for that matter) do not radiate as a black body!
best worldly example is to look at a filiment as the battery drains, as the battery is able to deliver less power the temperature of the filiment lowers, making the light warmer...
Tis all physics!
Posted:
Sat Nov 06, 2004 4:00 pmby gstark
Birddog114 wrote:Greg,
Great knowledge and wealthy information!!!!we send you to the show "who want to be a millionaire" then get the monies for lens lust
I suspect that Greg's knowledge of Kelvin might be better suited for The Einstein Factor.
Of course, I want to go on the Einstein Factor too; my subject of choices?
Questions for which the correct answer is "Pass".
Posted:
Sat Nov 06, 2004 4:14 pmby Greg B
Posted:
Sat Nov 06, 2004 7:11 pmby Killakoala
Gary, such as....
'Complete the name of the following geographical location, The Khyber ....."
Posted:
Sat Nov 06, 2004 7:13 pmby gstark
Steve,
Precisely.
"In a game of Rugby League, the act of throwing a ball, in a controlled manner, from one player to another is called a ???"
Posted:
Sat Nov 06, 2004 8:08 pmby bago100
Well said Steve!
also
"In a game of Rugby League, the act of throwing a ball anywhere in a panicked manner from the point of throw, to any player is called a ????
It will be in the D70 manual somewhere for sure! Yep! HERE IT IS!!!! page 196, second column, cleaning subheading, first word beginning on the 11th line down.
Cheers
Graham
Posted:
Tue Nov 16, 2004 12:17 pmby Matt. K
C'mon guys. When do we get the answers?
Posted:
Tue Nov 16, 2004 12:24 pmby gstark
Matt,
Pass.