![]() Most geometric aberrations can be corrected by interacting with the aperture - by adjusting it. Rays of light enter clearly through the center of the lens and are not objects to comatic aberration. The latter distortion is more noticeable the closer the image point is to the edge of the frame. ![]() The "tail" of such a comet can be directed toward the center of the photo (negative coma) or its edge (positive coma). In the photos, a coma can be seen in the "tails" of the comet stretching behind the single points of the image. Cometic InterferenceĪ chromatic aberration in the lenses, which affects only the light rays passing through the lens at an angle, is called a cometic (or simply a coma). Photographers using wide-angle lenses encounter such distortions most often. Pincushion distortion is usually caused by using the maximum zoom of the camera, while barrel distortion is caused by using the minimal zoom. As we said, light rays passing through the lens merge at a point large distance from the lens, as opposed to those rays passing around the edges. In the first case (with inwardly concave lines) this distortion is called "barrel distortion", in the second case (with convex lines) it is called "cushion distortion".ĭistortions are caused by the change in linear magnification provided by the optics across the field of the frame. Impact of Chromatic Interferenceĭistortion is a type of lateral chromatic aberration, where the unnaturally convex or concave-looking contours of objects are not the photographer's artistic intent. One of the simplest and most understandable phenomena of dispersion is the rainbow or glare of light playing in cut gemstones. We are talking about the dispersion of light, which Newton discovered back in 1672. This is why this type of optical interference can be red, magenta, yellow, and any other hue. Halos are simply parasitic glare from a bright source in the frame. Sometimes people confuse purple and red halos in a photo with CA. Monoculars suffer greatly from spherical aberration. For example, above, the model's white shirt flows smoothly into the dark background, erasing the border. Transitions in the area in front of the sharpness area are colored purple, and out of the sharpness area, they are colored dark green.Ī spherical aberration example is the blurring of boundaries between contrasting elements in the sharpness area of a photo. Popular aberrations, usually in the fuzzy area, are called 'fringing around'. How to define chromatic aberration? Very often CA is pronounced in the in-front or behind-the-focus point. But as the saying goes: optimists invent the airplane, pessimists - a parachute, so you have to fight CA to get a good picture. Of course, there are several lenses (and it is lenses that give CA), which still strongly suffer from this malaise. Often CA adds different color spots and stripes, it is especially pronounced in the transition of contrasting objects, often cited as an example with trees. Just remember a physics lesson about the refraction of rays in a prism, and a lens is two prisms connected by bases. The main point of chromatic aberration definition comes from dispersion, simply put, when a white beam splits into its spectrum - this is due to the fact that rays with various wavelengths of light (different colors) are refracted at various angles as they pass through the lens. There are axial, spherical, oblique, and other kinds, but they all boil down to the distortion of a picture. Nowadays high-quality optics is very good at fighting with CA, so it is really hard to see them. Nowadays the struggle over CA is in full swing. pin-up posters, in the scene, please mark it NSFW.If you are an amateur, and you heard somewhere that some lens gives strong CA (color aberration, which is how they are most often called for short), and then you looked at the photo for a long time and did not see anything - do not get upset. If your content revolves around SFW themes but includes NSFW assets, e.g. ![]()
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