parfocal


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parfocal

(pɑːˈfəʊkəl)
adj
(General Physics) optics (of a lens) maintaining focus even if magnification is changed
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References in periodicals archive ?
Like other high-end cine lenses, the MK18-55 operates as a parfocal lens.
Attenuator 5x reflector turret, motorized Fluorescence filters GFP (EX BP 470/40, FT 495, EM BP 525/50) Fluorescence filter Cy3 (EX BP 550/25, FT 570, EM BP 605/70) 4x lens revolver, coded, lens lift = 22 mm Mechanical parfocal adjustment 10x diving lens, apochromatically corrected VIS - IR; NA = 0.
The 21- and the 15-mm models are 2-inch eyepieces and are indeed parfocal with each other, as were the 10- and 15-mm eyepieces.
This effectively doubles your reach, and reach on a Super 35mm camera with a parfocal and fixed-aperture lens beyond 200mm (300mm after crop factor considerations) has few options.
A 60mm parfocal distance and a much larger barrel diameter allows these objectives to offer increased brightness and the highest possible combination of working distance and numerical aperture (for light-gathering ability).
The Vinden CZ 640 has a 35 -105 mm continuous-zoom parfocal lens with a 3x optical zoom, 4x digital zoom, and horizontal field of view (HFOV) from 17.
Designed for researchers who previously needed to align two cameras to a dual port, the system is essentially two complete, high-performance parfocal and parcentric cameras in one.
The intuitive interface, proprietary light cubes, dual cameras, precision automated stage and parfocal optical system enables users to produce publication-quality images in seconds.
The H3-ZA offers a parfocal zoom function to provide 2x zoom without refocusing.
Such an action provides evidence that the student knows the microscope is parfocal.
The optical system's range of achromatic and planachromatic objectives are parfocal and parcentered.
The different objectives are designed to be parfocal, and therefore require only fine adjustment of focus when rotated.