The optical axis of the lens is crooked.

The optical axis of the lens is crooked.

The optical axis of the lens is crooked. Photography can show the world in one's eyes to others through shooting and techniques, and can also record many beautiful things. Many people want to learn photography, but they still have a lot of theoretical knowledge about photography. Let's share the contents of the lens' crooked optical axis.

Lens optical axis deflection 1. If it is clear, it is out of focus.

Optical axis deviation is generally caused by violent collision of lenses. Of course, some cheap lenses use plastic lens barrels, which will also cause optical axis deviation due to wear and deformation after long-term use. But it doesn't mean that the new lens will be fine. There are so many lenses in a lens, even if one lens is installed by a few tenths of a millimeter, it may cause serious image defects. So, if you can afford it, try to buy high-end lenses, or at least assemble them more carefully.

The influence of optical axis deviation on the image is that the imaging of local area is not clear. For example, the definition of one of the four corners of a photo is obviously poor, which is basically caused by the deviation of the optical axis. Or, half of the images are unclear, which is also an optical axis deviation (or the camera cmos itself is biased).

If a photo is not clear near the edge, strictly speaking, the range of a circle radiated from the center of the photo is not clear. This is not a fault, but the phase field is bent or the edge resolution is weakened, which belongs to the choice in lens design. Wide-angle lenses generally have the phenomenon of phase field bending and edge resolution weakening, and even some top lenses can't escape this list.

The optical axis of the lens is crooked. 2 The method of identifying the "optical axis deviation" of the lens is as follows:

1. Obtain the standard image obtained by imaging the graphics card with a super wide-angle lens in an ideal state, and calculate the distance between concentric images in the standard image.

2. Clamp the ultra-wide-angle lens to be calibrated with a fixture, and adjust the distance between the fixture and the graphics card. The ultra-wide-angle lens to be calibrated images the graphics card to obtain an actual image.

3. According to the distance between the original images of concentric circles on the drawing card and the distance between concentric circles in the standard image, the ellipse images in each ellipse image and the standard image are calculated.

4. Make the optical axis of the lens perpendicular to the parallel lines. A set of parallel lines is parallel only in one case, that is, the optical axis of the lens is perpendicular to the parallel lines. In any other case, the parallel lines will intersect to determine the lens offset.

Lens optical axis deflection 3, preparing a lens barrel with a first lens, a second lens, an optical axis detection system and an optical axis adjustment system, wherein the lens barrel has a central axis;

Installing the second lens in the lens barrel, and detecting whether the combined optical axis formed by the second lens and the first lens coincides with the central axis through an optical axis detection system, and if so, no correction is needed;

If not, the optical axis detection system measures the offset of the combined optical axis relative to the central axis and feeds it back to the optical axis adjustment system, which adjusts the combination optical axis to coincide with the central axis according to the offset fed back by the optical axis detection system to form a lens.

Taking the plane where the first lens is located as a reference plane, which has an X axis and a Y axis perpendicular to each other and a Z axis perpendicular to the reference plane, the optical axis adjustment system can drive the second lens to move along the X axis and/or the Y axis and/or the Z axis respectively, and/or the optical axis adjustment system can drive the second lens to rotate along the X axis and/or the Y axis and/or the Z axis respectively.

Taking the plane where the first lens is located as the reference plane, which has mutually perpendicular X axis and Y axis, and the Z axis is perpendicular to the reference plane, the optical axis adjustment system can drive the lens barrel and the first lens to move along the X axis and/or Y axis and/or Z axis respectively, and/or the optical axis adjustment system can drive the lens barrel and the first lens to move along the X axis and/or Y axis and/or Z axis.

When the optical axis adjustment system adjusts the combined optical axis to coincide with the central axis, the optical axis detection system detects the deviation between the optical axis of the second lens and the optical axis of the first lens in real time until the combined optical axis formed by the second lens axis and the first lens is adjusted to coincide with the central axis to form a lens.

The second lens is a lens or a lens group.

The first lens is a lens or a lens group.

The method for measuring the offset between the combined optical axis and the central axis by using the optical axis detection system comprises the following steps: preparing a scene to be shot; Acquiring an image of a scene to be photographed by the principle that light passes through a lens composed of a first lens and a second lens and is imaged on an image sensor; Processing the image to obtain an image quality score of a predetermined position of the image; And analyzing the offset between the combined optical axis and the central axis.

The preset positions are the four corners and the center of the image.

The method for acquiring an image of a scene to be shot through a first lens and a second lens comprises the following steps: taking pictures of the scene to be shot by using the principle that light passes through the lens composed of the first lens and the second lens and is imaged on an image sensor to acquire an image.

The method of obtaining the image of the photographed scene is based on the principle that light is imaged on the image sensor through a lens composed of a first lens and a second lens, and the optical axis detection system photographs the image through the first lens and the second lens.

According to the lens optical axis correction method, whether the second lens needs further optical axis correction is judged through the optical axis detection system, so that the combined optical axis of the second lens and the first lens coincides with the central axis; if further correction is needed, the optical axis adjustment system can adjust the relative position between the second lens and the lens barrel according to the optical axis deviation detected by the optical axis detection system, so that the combined optical axis of the second lens and the first lens coincides with the central axis; on the one hand, the combined optical axis formed by the second lens and the first lens can easily coincide with the central axis, so that On the other hand, overlapping the combined optical axis formed by the second lens axis and the first lens with the central axis can ensure the imaging quality of the lens and make the user experience better.