field flattener

field flattener

[′fēld ‚flat·ən·ər]
(optics)
A thin planoconvex lens placed in front of the photographic plate in some telescopes that have a curved focal plane so as to focus light on the flat plate.
References in periodicals archive ?
9 APO refractor and a 2-inch field flattener, the system produced good corner-tocorner star images with little vignetting.
The Field Flattener Lens System[TM] works in combination with the wide field of view for sharp edge-to-edge viewing.
4 for WX 10x50 IF), while their Field Flattener Lens System compensates for a curvature of field across the entire field of view.
Field flattener lenses produce edge-to-edge clarity and require less refocusing.
Field Flattener Lenses: These lenses are located between the prism system and the ocular-lens system.
The EL 42 uses new field flattener lenses to create a true image and super bright image resolution all the way to the very edge of the field of view without any edge distortion.
Using field flattener lens, which helps to create a true image, for the first time it is possible to produce diamond-bright image resolution right up to the very edge of the field of view ensuring the finest detail without any edge distortion.
The scope's 3-element f/8 objective is made with ED glass, and an optional field flattener is available as well as an optional focal reducer.
The HD lenses work in concert with the Field Flattener lenses to produce edge-to-edge clarity; less focusing, rich contrast, and color fidelity in a wider field of view.
The Field Flattener system will help relieve eye fatigue by minimizing curvature at the edges of the viewing area.
Our test telescope on loan from the manufacturer came with an optional ($150) field flattener that retains the telescope's f/7 focal ratio and 714-mm focal length.