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Re: Light Meters

In a message dated 8/23/00 3:57:21 AM Eastern Daylight Time, 
Aquatic-Plants-Owner at actwin_com writes:

<< An f-stop is a factor of 2 (100% increase).
 One quarter f-stop is a factor of 1.19 (a 19% increase).... Wars have been 
fought over less.  A 19% increase is what you get from  adding a fifth tube 
to a four tube fixture (figuring in obstruction  issues).  If choosing one 
reflector over another, 19% is a huge difference. >>

Yes, Thank you. I sort of knew that about f-stops and it's log scale.  now, I 
have not bought any photographic equipment in years. No need for new gadgets 
and  bell and whistles that  really don't do much except lighten the pocket.

The meters I have, came with EV to lumen -- lux conversion charts --
(Pentax 1 degree digital spotmeter, modified by Zone VI  <<this is a VERY 
Special meter> and a Minolta combo incident and flash light meter. Then there 
is the built In 1 degree spot capability on my F4.  The problem with any 
conventional light meter is that they are calibrated to accurately  measure a 
19 % gray card -- so they lie about 1/3 of the time. The trick is to  know 
what those conditions are and compensate for it. A great deal of good quality 
used photo equipment is listed for sale at rec.photo.marketplace.

It was not my intent to start a war. I'm a peaceful soul at heart, and four 
years in Vietnam cured me of any aggressive tendencies I might have once had.

The problem with lighting I have in my tank is -- too much. And the chart 
posted by  another lister from the French book graphically illustrated that.  
Thus far, 220 watts of 9230K PCs seems more than enough for my 120 gallon 
tank populated mainly with four different swords, and a mess of various types 
of vals. (but I have a standby extra 110watt fixture  leaning against a 
corner in the back just in case.