Thursday, May 7, 2009

Animation Frame Capture - Video Capture

I cover this topic in detail in the downloadable PDF booklet "Image Capture Techniques For Hand-Drawn Animation" which you can get by clicking on the link.


At the pencil test stage one option for getting your hand-drawn artwork into the computer is to capture your frames with a digital video camera mounted on a down-shooter (could be a sturdy tripod, but preferably a Copy Stand). Drawings meant to be digitized for final coloring should be captured using a scanner , which I'll discuss in the next article.

The camera is pointed straight down at a shooting stage which has an Acme peg bar embedded or taped along the edge. The drawings are placed one at time under the camera and each drawing is captured as a single "frame" taken by the the animation software (i.e TVP or Digicel, etc.) via the live video feed from the camera. Digital video camera is attached to the computer via firewire (IEEE 1394) cable.

Here are photos of typical video pencil test stations with mini-dv camcorders used to shoot the drawings.

(click on the images to see them larger)

You can still find relatively simple, inexpensive Copy Stands at photography supply stores and on eBay. A popular line of copy stands that have been used for pencil test stations are the CS-3 and CS-2 line of copy stands made by Testrite Co.

Testrite CS-3 copy stand being used for shooting pencil tests:

The Testrite CS-3 an CS-2 copy stands are no longer in production, but they show up often eBay. Other brands of copy stands made by Bencher, Kaiser, Beseler, and Bogen will work equally well. You do not need to get one of the super-expensive models with a geared column and professional quality photo lights. Basically all you need is a sturdy column to hold your camera securely in place and a platform or "stage" underneath to tape-down your Acme peg bar. (the "stage" should be large enough to accommodate standard 12 and/or 16 field size animation paper.)

A tripod may also be pressed into service to shoot your animation. Be sure that the legs are secured so that they don't get moved during a shoot.

Lighting is very important when shooting your pencil tests. You should have bright, diffused lighting aimed down at the artwork at about a 45° angle to eliminate any shadows or over-exposed hotspots on the artwork. Adjust the lights and the manual exposure and white balance of the video camera until you have an image where the white of the paper is as light as possible , but the image of your pencil drawing is sharp and clear.

The spiral type of fluorescent bulbs called "Cool Bulbs" which are about 150 watt-equivalent can be used with inexpensive metal reflectors (clamp-on shop lamps) with ordinary white paper taped over the lamps to diffuse the light. If you have any open windows or other strong light sources other than the light you are shining on your animation drawings you should mask off the windows with heavy shades or black paper taped over the window , and/or mask off the shooting area so stray light does not fall on your shooting surface.

(click image to see it larger)

A regular consumer-level mini-dv camera such as the Canon ZR-960, most cameras in the Sony HandyCam line, or the Panasonic PV-GS320, PV-GS90 or PV-GS80 cameras can be used for video frame capture. (as long as the camera has an IEEE 1394/firewire out port it should work fine)

Canon mini-dv camera mounted on Kaiser copy stand.
Pencil line test system shown is Toki Line Test:

Many other types of mini-dv cameras will be usable too. The main thing is that the dv camera should have an IEEE 1394 "firewire" interface and your computer will need a firewire port to plug it in. You should also make sure that any dv camera you plan to use for shooting your animation has manual override of focus, exposure, and white balance and that it will operate without a video tape or disc loaded in the camera (some brands will not operate or will not stay on continuously if there is not a video tape in the camera. You want to get one which will operate continuously providing a live video feed without a tape or disc loaded, because you are NOT recording directly to the tape or disc. For animation frame capture purposes you are only using the live video signal feed that is provided by the camera.)

You may even use a webcam such as the UniBrain Fire-i web cam although you should be aware that web cams are lower resolution (typically 640 x 480 max. resolution) and will not give as high an image quality as a DV camera.

The aGent V5 webcam will also work fine for shooting pencil tests with TVP or Digicel.

Some webcams do not allow manual over-ride of the focus or exposure, so are not usable because they will constantly be "searching" for a focus point because the flat, white surface of the paper does not give the camera anything to grab on to for focus. Your images may go in-and-out of focus from frame to frame if you can no lock down the focus to a fixed focus point. Better to use a digital video camcorder if possible, or a webcam such as the aGent V5 or Unibrain Fire-i which have manual focus.

If you can find a CCD "security camera" type of video camera will tend to give higher quality images for your pencil tests than a typical consumer-quality digital video or mini-dv camera. Sometimes these types of cameras can be purchased inexpensively from electronics surplus stores or from eBay. Purchased new they are typically more expensive than most consumer-level dv cameras and can be more trouble to hook up and run (and to purchase the necessary analog video-to-digital adapter) , but these cameras do have higher resolution and will give a better image quality overall. (though not as good as a scanner, which we'll discuss below.)

B&W "security monitor camera" mounted on copy stand:

Look for a surveillance/security camera with these features:

1.) S-Video Out connection if possible. (many have BNC "composite video" connection out , but S-Video is better quality than BNC, although BNC can work if you can find the right kind of adapter to get the feed to interface with your computer. )

2.) Manual over-ride on the lens shutter to adjust exposure

3.) Manual focus on the lens. Lens should be able to focus in range down to 12 inches.

4.) A zoom lens is helpful, though not necessary if the column on the copy-stand can be adjusted up and down.

Be aware that if you use this type of camera you will need to purchase an adapter such as the PYRO A-V LINK to feed the S-Video out or BNC Video out connection cable to your computer. Another suitable adapter is the Canopus 77010150100 ADVC110 Converter . The adapter will convert the analog S-Video or BNC Video signal to a digital signal that can be inputted to your computer. Be sure that the animation application you are using can read the signal . (if in doubt ask the Tech Support Dept. of the software you are using for frame capture.)