Video Seminar by Steve Fish

Part One covers Housing Techniques and concentrates on things you can do with your housing to make your UW video quality improve. view part 2>>> view part 3>>>

There is nothing you can do to make the water more clear. But that doesn't mean that you can't make the water LOOK clear. As a matter of fact, there's a very simple thing you can do to make it look more clear and that is to shoot through less of it! The photo to the right is a single frame from a video scene shot about 15 ft. from the subject. It looks fuzzy and has low contrast and color saturation.

The frame on the right is exactly the same turtle, same day, same time. The only difference is that it was shot at a distance of about 4 feet. By using the camera's widest angle of Zoom and minimizing the distance from camera to subject, you are shooting through less water and therefore the image is sharper, contrasty and has better color saturation.

This split frame shows the difference side by side. The moral of the story, don't use the zoom to crop your image, always shoot at the widest angle possible to minimize subject distance and maximise sharpness.

This goes for Macro and Close-Up too. The split frame to the left is the same subject, one shot zoomed out to max telephoto (about 5 ft. from subject) and the other at full wide angle (about 1.5 ft. from the subject)

DEPTH OF FIELD

Depth of Field is the near to far range of acceptable focus in a scene. With a small amount of DOF (illustration to the right), very little of what is close to the camera or far away is sharp. With a large DOF (illustration below) everything is sharp from things very close to the camera to things that are very far away.

Two primary factors that affect Depth of Field. One factor is lens aperture. But since we usually rely on the camera's auto-exposure capabilities, that is not something we have direct control over. The other factor is focal length. Wide angle gives lots of DOF and Telephoto gives very little DOF. This is another reason that we want to shoot at full wide angle whenever possible.

LOCK YOUR FOCUS

We can use depth of field to eliminate a common focus problem. The camera's autofocus needs good contrast to work well. In low contrast scenes, it will constantly "seek", causing the focus to go in and out. If you plat the video clip on the right, you will see that the focus is initially OK on the turtle because it has good contrast, but when the scene pans up to the Barracuda school, the focus "seeks" because of the low subject contrast.
View a video example. Video Requires Quicktime 7 player click here to download.

The solution is to utilize your depth of field. To do this, first you must zoom to full Wide Angle. Then point the camera at something with good contrast about 3 ft. away. Press the "Momentary Autofocus" button on your housing and the camera will force a proper focus setting. When you release the button, the focus "Locks" on that distance and your depth of field will make everything sharp from a few inches to about as far as you can see. When you play the scene to the left you will see that by locking the focus, when the camera pans up to the Barracuda school, it doesn't seek focus because it's locked.
View a video example. Video Requires Quicktime 7 player click here to download.

USE YOUR FILTER

You must use the filter built into your housing to get acceptable color balance. The images in this section illustrate that if you don't use your filter, your video will look horrible regardless of depth or camera white balance setting. About the only time you would want to shoot without the filter is when you are shooting scenes above water before and after the dive, or doing an In/Out shot.

SET YOUR WHITE BALANCE MODE

Many cameras allow you to set the "White Balance Mode". Usually there are three primary modes, Daylight, Indoor and Auto. The Daylight mode forces the white balance to be as warm as possible. It is usually only used when shooting very deep. The Auto mode works well from about 25 feet down to about 80 feet. Above 25 feet, the filter will begin to "overcorrect" more than the Auto white balance can handle, so you would switch to "Indoor" which cools it back down to a pleasing rendition.

OTHER WHITE BALANCE ISSUES

Some cameras only have an Auto white balance mode. In that case you should make sure that you give the camera a few seconds to adjust the color. It doesn't react to color changes as fast as it reacts to exposure changes. If you make a major depth change that will result in a color change, give Auto 20 or 30 seconds to catch up with it's correction. You don't have to be filming for it to make the correction. The split to the right shows the same scene shot right after a depth change and after a 30 second wait.

You should strive to get your color as close as possible as you shoot, but sometimes it just isn't possible. In instances when overcorrection is unavoidable, always opt for over correction rather than undercorrection. It's easier to take excess red out in post production than it is to try to create red that wasn't there!