The phrase refers to readily available visual aids designed to assist in achieving precise focus when using a camera. These aids, typically in the form of downloadable and printable documents, provide a standardized pattern or series of markings that enable photographers to accurately assess and adjust the sharpness of an image. A typical example includes a chart with contrasting lines or shapes which, when viewed through the camera lens, allows for fine-tuning the focus until optimal clarity is achieved.
The importance of these resources lies in their contribution to photographic accuracy and image quality. They enable repeatable and reliable focusing, particularly beneficial in situations where manual focus is preferred or necessary, such as macro photography, product photography, or scenarios with challenging lighting conditions. Historically, such tools have been crucial for photographers reliant on manual lenses and focusing systems, offering a cost-effective method for ensuring sharp and well-defined images.
The following sections will explore the practical applications of these charts, delve into various chart designs, and discuss their utilization in calibrating lenses and camera systems to optimize overall performance.
