The slit lamp has parfocal
zoom optics that deliver a 200 f m diameter beam to the human retina.
Like other high-end cine lenses, the MK18-55 operates as a parfocal
Meade also claims the MWA series are parfocal
, meaning that they reach focus at the same point.
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 17.1 degrees to 1.5 degrees.
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
. I can usually fill in Blanks 7 and 8 at the same time.
The optical system's range of achromatic and planachromatic objectives are parfocal
The different objectives are designed to be parfocal
, and therefore require only fine adjustment of focus when rotated.