The sensor size in a digital camera impacts lens selection and noise reduction. Larger sensors are less susceptible to digital noise -- typically colored pixels that appear in the darkest portions of an image. Full-size sensors are 36 mm by 24 mm, the same size as a 35 mm negative. Many cameras with full-size sensors will accept older lenses designed for 35 mm film, though all the functions may not work. But some digital single lens reflex cameras and all point-and-shoot cameras have smaller sensors. This has the practical effect of increasing the focal length of a lens, if designed for film or a full-size sensor, and it limits the use of wide-angle lenses with such cameras. There are three approaches to getting wider-angle views, despite these limitations.
- Dedicated wide-angle lens
- Supplementary wide-angle lens
- Lens adapter
- Photo editing software
Replace the normal lens with a wide-angle lens dedicated to the camera sensor size. This is the most expensive approach, but it offers the highest quality. The resulting images should be sharp from corner to corner. They should be free of chromatic aberration -- odd color effects that look like glowing edges. They should have minimal internal reflections when pointed at a strong light source, and they shouldn't exhibit barrel distortion -- an effect that makes parallel lines bulge outward in the final image.
Add a supplemental wide-angle lens in front of the existing lens. This will work for some compact cameras and digital single-lens reflex cameras -- or DSLRs. Supplemental lenses are offered by both original equipment manufacturers and aftermarket companies. With a DSLR, the supplemental lens simply screws on in front of the main lens. Compact cameras or point-and-shoot models need an adapter. This is usually a tube that attaches over the existing lens with the supplemental lens mounted to its front. The main lens is free to move inside the tube. These lenses are less expensive than a wide-angle lens and are a practical alternative for occasional use, though they're not as sharp in the corners and may suffer from internal reflections.
Use the camera's panorama function or photo editing software to achieve a wide angle. Some cameras offer a panorama function that stitches photos together. Photo editing software like Photoshop, Pixiq or Zoner Photo Studio also can do this. Regardless of the method, here are a few tips for better results. Try to visualize the final image, figuring out where the image will begin and end. Try to overlap generously, though this isn't always possible with in-camera panorama functions. Take the photo sequence using a normal or short telephoto setting for the lens, which introduces less distortion. If possible, use a tripod to ensure that the camera is level throughout the sequence.
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