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Re: Tank pictures

> There are films with excellent latitude that can be overexposed by several
>  stops and still produce a good quality print.

If I may make a few suggestions here...  there is no reason to purchase film 
that can be over or under-exposed.  As with anything else in life, there is 
only one "correct" exposure, and anything other than this exposure will 
result in a degraded photograph.  No film can possibly equal the dynamic 
range of the human eye.  Film is engineered to record a certain range of 
light, and different films are designed to produce different results.  The 
trick is in getting that dynamic range to then print on paper, which is the 
limiting factor.  "Light range" is determined by the amount of light falling 
on the whitest part of the subject, vs. the amount of light falling on the 
shadows.  If you had twice as much light (1 f-stop) on the highlights as on 
the shadows, then you would be lighting that subject with a 2:1 range.  If 
you had 4 times the light (2 f-stops), the range would be 4:1. 8 times the 
light (3 f-stops), etc. etc.  Film can easily record a light contrast range 
of 100:1, while Kodak Ektacolor paper can only reproduce a light range of 
10:1.  (Other brands of print paper are similarly limited.)  Wedding 
photographers are faced with similar problems, where they try to record fine 
detail in the bride's white dress, while simultaneously recording detail in 
the groom's black tuxedo.  The trick here is to arrange lighting so that it 
does not exceed the 10:1 maximum ratio possible with paper.  Translated into 
English, this means that the shadows in the subject (aquarium) should record 
so that they just show up on the photographic negative (just above base 
density, or the clear, unexposed area of the film between frames).  The 
brightest highlights should then record no greater than 10:1 above the 
shadows.    This is achieved by adjusting the "fill" light (the light that's 
lighting up the shadows, from just over 45 degrees from the side of the tank) 
to provide that low light detail in shadows.  Then, the "main" light (the 
light above the tank) should be adjusted so that it is about 3 f-stops 
brighter than the "fill" light.  If the lights are equal in power, this is 
easily achieved by adjusting distances.  Light falls off at a predictable 
rate with distance.  The distances conveniently correspond to the f-stops on 
your camera lens.  For example, if the main light were 2.8 feet above the 
tank, then the fill light would be "3 f-stops" away from the tank 45 degrees 
to the side, i.e., 8 feet to the side.  If the main light were 1.4 feet above 
the tank, then the fill light would be positioned 4 feet to the side.  This 
lighting arrangement would give an 8:1 contrast range, well within the 
printing capabilities of common color paper.  The use of Vericolor film (or 
if you prefer a Japanese film, use Fuji Professional NPS 160 film) will 
guarantee that you are using a film specifically formulated to resolve the 
"white dress, black tuxedo" problem, and this problem is very similar to the 
aquarium's "highlighted plants, plants in the shadows" problem.  If you 
follow this formula, your aquarium pictures will always print properly on 
ordinary color paper using inexpensive machine printing, and you don't have 
to resort to special custom printing, or dodging or burning to retain detail 
in both shadows and highlights.