Full Tank Photography

Having shot the inhabitants of the tank, now it is time to get a view of the world they live in.  Full tank shots give us perspective as to the placement and environment from which the macro shots were taken.

Wide Angle Lenses
The space in front of our reef tanks is typically limited.  In the case of my personal tank, it is the width of a hallway.  As such, we often need to use wide angle lenses to capture the entire view.  Keeping in mind barrel distortion increases as we go wider, we want to shoot from as far back as possible.  This typically means shooting from across the room from the back wall.

If, however, we are lucky enough to have a football stadium for a room, you do not need to shoot with a 1,000mm telephoto lense, as this will create pincushion distortion effects (like poking a pin into a cushion, the edges bow inwards, toward the center of the image).

An ideal shot would be to be able to fill the frame with the zoom set somewhere in the middle of the digicam's range.

Balancing Light
When photographing reef tank setups, we have the issue of dealing with multiple independent light sources.  Say our room is lit by sunlight filtering in through a window.  It seems a bit dim, so we flip on our overhead halogen lights to brighten up the room.  However, in contrast to the metal halides hanging over our tank, the room still appears quite dark.

Multiple light sources further complicate the issue by having different color temperatures from each source, and we must choose one to base our white balance on.

In this example, our setup was exposed for the surroundings.  The cabinetry and walls are all properly exposed, however, the reef is completely blown out and all we see is a blue blob.  The ambient light levels were much lower than that of the tank, and therefore the tank appears too bright.

In this second photo, we exposed for the tank.  Now the situation is reversed.  The tank is nicely exposed but the surroundings are too dark.  We need some supplemental lighting.

In this photo, the tank lights were powered down and a flash was used as the main source of light.  As we can see, the tank is completely dark.  We need to combine the two sources of light.

Here we used both sources of light taking care to balance the two so both areas of the image are properly exposed.  We first set the camera to measure the ambient light emanating from the tank, and used that to set our exposure.  We then used the flash to fill in the extra light needed to expose the external surroundings properly.  The result is a well balanced photo that shows both the tank contents and its surroundings.

Reflections
When shooting glass or any other reflective surface, we need to pay special attention to reflections.  In the example below we can see the light source (window) and the railing reflected off the glass.  Not only is this distracting to the viewer, but it also destroys contrast and makes it difficult to see the contents of the tank.

Curtain:

We want to keep light sources from reflecting off the surface of the glass.  The simplest way of dealing with reflections is to find the source and block it.  Roll the mouse cursor over the image to the upper right to see the same shot taken without and with a curtain.  For the series of photographs above, the reflection was eliminated by hanging a curtain, thereby blocking the reflection source.  The result is a series of shots with good contrast and no distracting elements.

This method, however, does not work for secondary reflections from the flash, as they occur in front of the curtain.  In this sample below, the flash reflection off the walls and molding wash out the tank contents and we see what looks almost like a white sheet over the tank.

Circular Polarizer:

 

A circular polarizer helps in these cases.  Simply pop the polarizer on the lense and turn until the reflections disappear.  The polarizer works by filtering out random scattered light and allowing only direct reflected light through.

The employment of a circular polarizer on this photo eliminated the reflections caused by the flash.  To see its effect, roll the mouse cursor over the photo on the upper right.

The downside of using a circular polarizer:

• Because it filters out light it eats 1 to 2 stops of light.
• Circular Polarizing Filters are expensive - one of the most expensive filters we can buy for our camera.
• One is needed for each different thread size we anticipate using it on (lense diameter).  Alternatively, we can get one for the largest thread size we own, and use step down adapters for smaller lense threads.
• It does not work on primary reflections, so don't think you can take your digicam and use the popup flash in conjunction with a polarizer and get reflection-less results, you will still have the blinding white spot in the photo.