The Role of the Camera
Count on adapting most photographic images. However, don’t let that discourage you from using your cameras. On the contrary, your camera is one of the most valuable pieces of equipment in your tool chest. Your camera is the first piece of digital device that enters your hand, works through your eye, and begins the translation from the real world to the digital medium. Use it! But be sure that it is worthy of your use. When you’re shooting photographs they will have to be at the highest resolution and pixel depth that your camera will permit (your camera should capture 6 megapixels or more).
If your camera is not of the higher-end variety you can consider using an SLR film camera. Shooting with film can give you sharper and better quality textures. But you will need to know a few things about these types of cameras.
You should have your camera with you at all times. You never know when a good texture is going to appear right in front of you. So be prepared.
Keep a record of information from your shoot in your journal. If you make this effort you wouldn’t be wondering where or what a texture’s history is.
When collecting textures through photography be sure to also take photos of the environment as a reference. Shoot a texture as a close-up to get detail. Shoot a medium shot to get detail placement. And shoot a long shot to get reference to the environment. In this way you can create a history for your texture.
Shooting with camera for your textures and references of textures requires a few good techniques. First, bracket when you shoot, using different exposures. This will give you different amounts of detail, and will almost guarantee that you will have something to work with when you return to your computer. If you shoot one shot and it’s not right, then you likely will have lost the texture. Of course, you can return and re-shoot in some instances, but the light and angle will be different.
Consider the advantages of shooting on a sunny vs. a cloudy day. A sunny day will have more contrast and brighter colors; a cloudy day less contrast and the colors will be muted, but your exposures can have more detail. Also the time of day will change your textures. If you shoot in the early morning or in the evening the light is more golden. In the middle of the day the light can wash off a lot of the color and things have a tendency to be more blue. Know when and what are the best circumstances for the look you are going for in your projects.
Remember, shoot at the highest resolution that your camera will allow. You will not get as many shots, depending on your card. But you are more likely to get textures that you can or alter if your resolution is high.
It is crucial that when you are preparing textures for your library or for a project that you consider the pixel range that will insure an appropriate amount of detail. Most digital cameras now offer low multiples of mega-pixel resolution, but some digital image banks request images of up to 20 mega pixels for a full range of manipulation. The key information to remember involving pixels is 1 mega-pixel is 1,000 x 1,000 pixels = 1,000,000.
The aspect ratio of most digital cameras is 1.33: 1. For textures you need 1.5 mega-pixel minimum, 2 mega-pixels to be safe. Remember, bigger in this case is best.
Foveon: Foveon Inc., previously known as Fovionics, is the company that makes the Foveon X3 sensor that captures images in cameras such as the Sigma Corporation SD-9, SD-10 and the SD-14 (announced in 2006-08) digital single-lens reflex. The name comes from the fovea of the human eye, which enables sharp imaging, used in activities such as reading and watching TV. Founded in 1997 by Carver Mead, Richard Lyon, Richard Merrill, Richard Turner, and others, and located in Santa Clara, California, Foveon was initially known for their high-end digital portrait camera systems built around a color-separation beam-splitter prism assembly. Both the prism system and the X3 technology derive their benefit from using all the light and sensing all colors at all locations.(Source: Wikipedia.org)
When dealing with CCD/CMOS remember:
* RGB: Each channel is represented by a separate pixel set.
* For an RGB feed, you need four times as many pixels as are present in the final display.
* RGB channels require a six mega-pixel minimum for input stream resolution.
When utilizing your digital camera, care must be taken to set focal length as close to your subject as possible. The Focal Length is the distance from the optical center of the lens to the film back. Depending on the lighting, the camera may be utilized in a hand-held configuration, or with a tripod in low-light situations. Camera Shake or stability issues are affected by shutter speed.
Among things to consider when shooting by hand is utilizing a shutter speed greater than the focal length of the lens.
Among things to consider when shooting with a tripod is shooting at a shutter speed smaller than the focal length.
The optimum focal length for texture acquisition can vary depending on the type of camera you utilize.
Focal length also can be variable depending on the size of the film back. When utilizing a 35mm SLR camera, a 200mm focal length minimum or larger is recommended. When shooting with a digital SLR, a focal length of approximately 150 is a recommended minimum. When utilizing a consumer point-and-shoot digital camera, an 80mm, or 2X or 3X setting is recommended.
Another factor to consider when using your camera for texture acquisition is the shutter speed. You will need to know what shutter speed your camera is set on when you are shooting.
Shutter speed is defined as the time during which the shutter is held open during an exposure. When the shutter is open, it allows light to reach the film or the image sensor in a digital camera. The shutter speed regulates how much light the camera will record, functioning in an inverted relationship with lens aperture settings.
Typically, a fast shutter speed requires a larger aperture to avoid under-exposure, while a slow shutter speed requires a very small aperture to avoid over-exposure. Long shutter speeds typically are used in low light conditions, including night photography.
Shutter speed is measured in seconds. A typical shutter speed setting on your camera for photographs taken in during normal daylight condition is 1/125th of a second. Apart from the effect of shutter speed on exposure, shutter speed affects the way movement is captured on film or in a digital image. Very short shutter speeds are used to capture fast-moving subjects. Very long shutter speeds can be used to artistically blur a moving subject. During the early history of photography, shutter speeds were often arbitrary, and film mediums were not very sensitive.
Aperture is the size of the opening in the shutter, through which light passes.
But now there is a standardized way of representing aperture in which each major step up exactly doubles, or each major step (f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16, etc.) halves the amount of light entering the camera. The standardized 2:1 scale has been adopted for shutter speed so that opening one aperture stop or reducing the shutter speed by one step results in an
Depth of Field is the distance in front of and beyond the subject that appears to be in focus. Depth of field also functions in an inverse relationship with aperture, so that the smaller the aperture the greater the depth of field, and the greater the distance the greater the depth of field.
There is only one distance at which a subject is precisely in focus, but focus falls off gradually on either side of that distance, and there is a region in which the blurring is imperceptible under normal viewing conditions. When you are shooting for textures you should have a shallow depth of field, meaning that you have as many planes in focus as possible. When you are creating textures you want them sharp and clear. Use the depth of field for your composites and possibly for your reference shots for both texture and mood.