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Re: Taking aquarium pictures with auto focus/exposure cameras: how?

> From: "Dan Dixon" <dandixon at home_com>
> Subject: Taking aquarium pictures with auto focus/exposure cameras: how?
> Any others? I'm wondering how the autofocus will work; seems like it would
> focus on the glass front instead of on the interior of the tank. 

Going back to a photography class a long time ago, the term "Depth of field"
applied here.  When you've got a wide depth of field, a large range of the
picture is in focus.  With a narrow depth of field, only the exact focus
point is in focus.   Many times this is used for artistic effect.  In the
case of documenting an aquarium, you probably want a wide depth of field,
so that the focused area would extend at least several inches into the tank.

> Should I use flash? I'd like to capture fish as well as plants.

I'd personally skip the flash, and put all the light you can get over the tank.
That will probably light it better than the camera flash.  Plus the built in
flash will produce some glare, even at an angle.

> What speed of film should I use?

The term "speed" is deceiving.  It is pefectly possible to catch fast
moving action with "slow" film (say 100 speed).  The Slow/fash film speed
refers to how sensitive the film is to light.  A slow film needs more
light to reach it for it to record the image.  A fast film needs less
light for it to record the image.  

The choice of film speed relates back to depth of field.    To get more
light to the film, the camera (or the photographer for manual cameras) 
will open the apeture(sp?) wider, allowing more light in.  But the wider
the apeture is open, the narrower the depth of field.  So, if you use a 
slow film, your camera will need to open the apeture wide, and you will
get a very narrow focus.   By using a faster film, the camera can set the
apeture narrower, producing a wide depth of field.

So, the short answer is to use a fast film, but I wouldn't go faster than
400, maybe 800, because the film gets too grainy.

Chuck Gadd