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Re: off topic (cameras)



> This is off topic, but you folks would know more about this than anyone
>  else I could ask.  Would a polarized filter help cut down on some tank
>  glare?  I understand all the other steps (I think), but would a product
>  like this http://www.cameratraders.com/cat/h/013pl.html help any? Its
>  only $25.
>
Since it pertains to photography of your planted tanks, I don't see how it 
could be considered off topic.  Polarizing filters can cut glare, but only if 
the light is coming from 90 degrees or so from the plane of the subject.  
They also work much better if the light is coming from a point source (i.e., 
the Sun).  Of course, any aquarium photography should be performed in a 
darkened room (night time?)  so that you're not fighting room glare, and you 
have complete control over lighting.  Polarizing filters also cost you 2 
f-stops of light, which means that you have to open your lens aperature by 2 
stops.  This costs you depth of field, which is always a problem with 
close-up photography.  The best way to light the aquarium is with the main 
light directly overhead, or above and slightly in front of the aquarium.  Any 
fill lights (if used) should be more than 45 degrees to the side of the tank. 
 The reason for this angle is that it eliminates problems of glare off the 
front glass, and thus negates the need for a polarizing filter.  Having said 
that, a polarizing filter is very useful if you are photographing, say, 
plants in the wild, or ponds, because those subjects do often suffer 
degradation of the photograph from light glare from the sun.  It's well worth 
keeping a polarizing filter in your camera bag at all times for outdoor 
photography.