A zoom lens system is provided that includes a compactly constructed focusing lens unit and that has a suppressed change in the image magnification at the time of movement of a focusing lens unit. The zoom lens system according to the present invention, in order from an object side to an image side, comprises: a first lens unit having positive optical power; a second lens unit having negative optical power; and at least two subsequent lens units, wherein the two lens units includes a lens unit A having positive optical power and a lens unit B arranged on the image side relative to the lens unit A, at the time of zooming, all lens units move in a direction along the optical axis so that intervals between the lens units vary, at the time of focusing, the lens unit B moves in a direction along the optical axis, and at the time of compensating image blur caused by vibration in the zoom lens system, either the entirety of a lens unit arranged on the object side relative to the lens unit A or a sub lens unit which is a part of a lens unit arranged on the object side relative to the lens unit A and is arranged on the image side therein moves in a direction perpendicular to the optical axis.

Zoom lens system, interchangeable lens apparatus and camera system

An optical system for imaging an object on an image acquisition unit. The optical system, from the object, comprises a first lens unit, a second lens unit, a third lens unit and a fourth lens unit in the direction of the image acquisition unit. The first lens unit comprises at least one lens group with negative refractive power. The second lens unit comprises at least one lens group with positive refractive power and the third lens unit comprises at least one lens group with negative refractive power. The second lens unit and the third lens unit overall comprise at least three lens groups. From the first lens unit in the direction of an image acquisition unit, the first lens group, the second lens group and then the third lens group are arranged. The three lens groups have a movable design for adjusting the focal length of the optical system.

Optical system for imaging an object

A Miniature zoom lens, in particular for use in mobile telephones, in which the zoom lens, as viewed from the object plane, has the following in the stated sequence: at least one negative first optical lens group, at least one negative second optical lens group, at least one positive third optical lens group, and at least one positive fourth optical lens group The second, third, and fourth optical lens groups are configured in such a way that focusing is achieved solely by displacement of the fourth optical lens group, and during the focusing the positions of the second and third lens groups remain unchanged

Miniature zoom lens

Method for producing an objective, in which the outer mounting includes an outer surface that is, at least in sections, limited by a plane which extends inclined toward the optical axis or which extends at a distance from the optical axis.

Method for producing an objective

Genetic Algorithm-Based Hyperparameter Optimization for Convolutional Neural Networks in the Classification of Crop Pests

A zoom lens optical system includes: a first lens group that is provided close to an object, has a negative refractive power in total, and includes an optical part having a surface that reflects light; a second lens group that has a negative refractive power in total; an iris; a third lens group that has a positive refractive power in total; and a fourth lens group that has a positive refractive power in total.

Small refractive zoom lens optical system

Utilizing pre-trained models involves fully or partially using pre-trained parameters as initialization. In general, configuring a pre-trained model demands practitioners’ knowledge about problems or an exhaustive trial–error experiment according to a given task. In this paper, we propose tuning trainable layers using a genetic algorithm on a pre-trained model that is fine-tuned on single-channel image datasets for a classification task. The single-channel dataset comprises images from grayscale and preprocessed audio signals transformed into a log-Mel spectrogram. Four deep-learning models used in the experimental evaluation employed the pre-trained model with the ImageNet dataset. The proposed genetic algorithm was applied to find the highest fitness for every generation to determine the selective layer tuning of the pre-trained models. Compared to the conventional fine-tuning method and random layer search, our proposed selective layer search with a genetic algorithm achieves higher accuracy, on average, by 9.7% and 1.88% (MNIST-Fashion), 1.31% and 1.14% (UrbanSound8k), and 2.2% and 0.29% (HospitalAlarmSound), respectively. In addition, our searching method can naturally be applied to various datasets of the same task without prior knowledge about the dataset of interest.

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Selective Layer Tuning and Performance Study of Pre-Trained Models Using Genetic Algorithm

A refraction-type small zoom lens optical system is provided to keep high resolving power in performing an AF(Auto-Focusing) operation from a short distance to a long distance with a few lenses and to secure the short full length. A refraction-type small zoom lens optical system is composed of a first lens group having the negative refractive force and comprising optical parts having a light reflecting surface; a second lens group having the negative refractive force; a third lens group having the positive refractive force; and a fourth lens group having the positive refractive force. The first, second, third and fourth lens groups are aligned from an object in order. The zoom lens optical system changes magnification by moving the second, third, and fourth lens groups and performs an AF operation by moving the second lens group when the object moves at a long or short distance. In changing magnification, an iris moves together with the third lens group. The distance from the first lens of the first lens group to an image surface is fixed although the lenses are moved in changing magnification or adjusting the focus.

Jae Cheol Jeong

Papers

Small refractive zoom lens optical system

Selective Layer Tuning and Performance Study of Pre-Trained Models Using Genetic Algorithm

Refraction type small zoom lens optical system