Large aperture lenses

low angles Depth of field becomes more apparent when shooting at low angles. By adjusting aperture and focus, you can control the range and effect of depth of field. Large aperture lenses and short focal length lenses produce a shallow depth of field, making the subject clear and the background blurry. This can highlight the details and three-dimensionality of the object being photographed. lifting and lowering The high-resolution lens with a head-up lift faces forward horizontally, which is suitable for capturing close-up details of tall buildings, or reflecting the magnificent high-altitude view after passing through the obstruction of the low-altitude view. Raising the lens can create the visual effect of the opening layout, while lowering the lens implies the end and the end of the aerial photography. The up-and-down megapixel lens is directed vertically downward, which is suitable for capturing the effect of looking down at everything on the ground from a God's perspective, and switching between local parts of the ground and panoramic views. If you add the clockwise or counterclockwise rotation of the aircraft during the upward and downward viewing process, the spiral effect can enhance the coolness of the picture. surround Surrounding camera lens is suitable for portraying the subject in all directions and angles, making the subject image more three-dimensional and vivid, allowing the audience to clearly understand the background environment around the subject. A surround lens allows you to capture a panoramic view so that all desired objects appear within the field of view. dive and fade away It is actually a combination of direct flight and lifting. While the aircraft retreats and advances, it performs lifting and lowering motion shots, so that the center of gravity of the picture is always kept on the subject. Fading away is suitable for shooting scenes that convey the overall environment from the close-up to the distant view of the subject, creating a condescending atmosphere, while swooping is just the opposite. Fading away or swooping shots often have a speed change process along the path to achieve a strong visual impact. Like a fisheye lens, it brings different visual effects to people. side flight The camera is facing the subject, and the aircraft is shot from the left or right side of the subject, flying straight to the other side. Compared with horizontal panning, sideways flight enhances the range of motion and sense of speed in shooting. In addition, you can also take simultaneous follow-up shots of the side of a moving subject to create an immersive visual experience. The drone flying sideways is like a recorder lens, recording the appearance of things to make the imaging more complete. panning The aircraft hovers in the air and moves its head left and right or up and down to take pictures. Panning is suitable for shooting scenes with a wide horizontal or vertical field of view. In the same geographical location, it can gradually display the complete space and explain more picture information. In addition, it can also be used as a shooting technique to gradually reveal the suspenseful atmosphere. Like a surveillance camera lens, it gives people a scary feeling that everything about them is being monitored.

Why do images presented by a lens have optical aberrations?A. DistortionDistortion will cause real objects to be straight lines, but in photos to be non-straight lines, to be curved lines.a) barrelb) pincushionc) complex/wavyTypes of lenses prone to distortion: usually zoom lenses and wide-angle lenses.B. Field curvatureFor plane objects in reality, after imaging, the real image surface is curved, and most actual sensors are also flat, which will cause the center field of view and the edge field of view to be unable to present clear images at the same time.Lens types prone to field curvature: usually wide-angle lenses and large aperture lenses.C. Vignettinga) Vignetting-----Light FalloffUneven brightness Light Falloff, the exposure of the center field of view and the edge field of view are different, resulting in inconsistent brightness between the center and edge of the picture, which is what we often call the camera vignetting problem.b) Vignetting-----Color CastUsually there is a color difference between the edges of the picture (especially the corners) and the center area. It is not entirely caused by lens aberration, filters and sensors will also have a certain impact.Types of lenses prone to vignetting: usually largeThere are many factors that cause optical aberration in lenses, some of which have been shared above:1) distortion2) field curvature3) Vignetting ---Light Falloff4) Vignetting ---Color CastIn fact, there are some other influencing factors:1) Focus ShiftWhen you reduce the aperture size, the best focus plane will move to the front or back. That is, the aperture size will affect the best focus plane position, which is what we call focus shift.Common lenses that are prone to focus shift: large aperture lenses. When adjusting the aperture, the focus usually needs to be re-adjusted.2) Onion ring bokehThere are some out-of-focus circular rays of light in the optical path of the lens, which is generally caused by a defective lens.Common lenses that are prone to "onionrings": Some large aperture lenses often use aspherical lenses because of the flatness of the surface involved during processing.3) Flare-GhostingWhen there are some abnormal colored patches in the presented image, usually like colored circles or colored blocks of specific shapes, we become ghost images.Common ghost images: zoom lenses, lenses with a large number of lenses, and large-diameter lenses. During processing, try to reduce the aperture as much as possible, or use post-image processing.4) Flare-Internal ReflectionsGenerally speaking, highly reflective objects inside the lens, such as structural parts with too high reflectivity, or dirty lenses in the optical path, etc. In most cases it is caused by workmanship issues.Common internal reflection stray light lenses:especially large aperture lenses, during the production process, you can try to eliminate light, cut off light, block stray light, increase transmittance, and reduce the aperture as much as possible when conditions permit.