Camera Setup

Project: Making a Scene in VR Worx

Making a Two Node Scene

For this particular part of the QTVR tutorial, I am proposing a two node scene project, which will review how to make an object movie and a panorama movie, both of which will be linked in a QTVR scene. The project is very specific, showcasing specific hardware and software and approaches which I hope will give you a feeling of how QTVR projects in general. I will provide a download link for the files that will allow you to follow along using the VR Worx Demo software, if you wish to do so. The Demo VR Worx software may be downloaded from VR Toolbox at http://www.vrtoolbox.com. The demo software will let you create QTVR movies, but you will not be able to save or export the results.

Planning for a Scene

Since making the QTVR panorama is part of a whole process of creating a QTVR scene that will link a panorama and an object movie. Before shooting your panorama, you should select a suitable object for a QTVR object movie and take it along on the QTVR pano shoot and make sure the object is visible in the panorama. Later you will put a hot spot on the object so you can pick it out of the panorama in the QTVR scene.

Setting Up to Shoot a Panorama

Equipment

The equipment we will be using in this workshop to shoot a QTVR panorama includes:

A Sony Maivca digital still camera. There are a host of quality digital still cameras to choose from to shoot panoramas. The Sony Mavica models are popular in grade schools because they use floppy disks to store the pictures, making it especially easy to transfer the pictures to a computer. Film cameras may also be used. The negatives or pictures may then be scanned to transfer to the computer, or a Kodak PhotoCD may be made from the film.
A Bogen photographer's tripod with a dual-tilt head. This tripod enables you to tilt the head in two directions for leveling. This is an important consideration when acquiring a tripod for QTVR panorama work. Most video tripods tilt in only one direction.
A Kaidan Kiwi+ pan head, especially designed for QTVR work. Important features of this specialized equipment includes the ability to mount the camera in portrait orientation, built-in leveling bubbles, and click stops set at specific degree increments. (for more info see http://www.kaidan.com)
A small leveling bubble, for leveling the "twist" orientation of the camera on the Kaidan pan head.

Setting up the Camera

Remove the quick release tab from the camera by flipping the release lever and lifting the tab out. Pull up the D-ring on the bottom of the tab so you can screw the tab onto the bottom of the Kaidan Kiwi+ pan head bottom bracket. Replace the tab onto the tripod head by putting one side of the tab under the lip of the recess opposite the grey cam and pressing the other side of the tab against the brass button in the recess. This releases the spring-loaded cam that locks the tab in place.

Slide the vertical bracket of the Kaidan pan head onto the bottom bracket, making sure the cork side of the bracket faces the rotating hub and leveling bubbles. You may have to loosen the set screws on the bracket to get it to slide on the bottom bracket.

Attach the camera to the vertical bracket. There are a number of ways to do this. For the Mavica camera you should mount the camera with the disk drive at the top, as shown, in case you need to change disks in the middle of a shoot.

To avoid parallax, position the axis of rotation of the pan head over the nodal point of the camera lens. The nodal point is where light paths cross inside the lens before focusing on the film plane (or CCD chip in this case). First slide the vertical bracket on the lower bracket so that the center of the pan head hub is lined up with the center of the lens' diameter, as shown. Then loosen the camera mounting screw and slide the camera to where the axis of rotation is a little bit behind the front element of the lens, as shown.
(Parallax is an geometrical concept of great practical importance. It is the apparent motion of a foreground object relative to the background when you shift your point of view. Since we are stitching a number of pictures together using their overlaps, we don't want this apparent shift.)

Next you will level the camera, but before doing that it is important to make sure that the two leveling bubbles on the Kaidan pan head are parallel to the tripod leveling handles. This will enable you to level one bubble and then level the second bubble without putting the first bubble out of level.

Now you can level the camera by leveling it in one tilt direction, locking it down, and then leveling in the second tilt direction.

You also need to make sure the camera itself is mounted level on the vertical bracket. Place a small leveling bubble on a flat place on the top of the camera to do this. Loosen the camera mounting screw and twist the camera to its level position, as shown. This has to be done after the Kaidan pan head has been leveled.

There are a few details you may want to check before you shoot the panorama:

The Kaidan pan head has different clickstop disks for different cameras. For the Sony's 40 mm lens, you will need to take 18 pictures to get the right amount of overlap between each picture, so you will want to make sure the 18 click disk is installed.
To get that many pictures on a single floppy disk, check to see that the camera is set to take pictures at the 640 X 480 pixel Image Size and at the Standard Quality setting. You can take larger or higher quality pictures, but you will probably need more than one disk to get them all.
Finally, make sure the camera is zoomed all the way out to its widest camera angle.

Hold the camera and tripod with steady hands to avoid camera shake. The camera must autofocus before it takes a picture, so you may need to hold the shutter button down firmly for a second or so. On the Sony Mavica camera you will hear an audible shutter click, and then see a "recording" message on the camera LCD view finder. Rotate the camera clockwise to the next clickstop position and take the next picture. Repeat until you have taken all 18 pictures. The camera display shows how many pictures have been taken on the disk, but it is always helpful memorize the framing of the first picture so you will know when you've gone all the way around.

Next: Stitching a QTVR Panorama Movie

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