focal ratio वाक्य

:The reason photographs taken at higher focal ratios are dimmer is because cameras shrink the aperture to increase the focal ratio.
Even though the principles of focal ratio are always the same, the application to which the principle is put can differ.
:The reason photographs taken at higher focal ratios are dimmer is because cameras shrink the aperture to increase the focal ratio.
His first camera had an aperture of about 360mm or 14.5 " in diameter, and a focal ratio of f / 1.75.
UH88 is a Cassegrain reflector tube telescope with an f / 10 focal ratio, supported by a large open fork equatorial mount.

The glass plate will usually break if bent enough to generate a curve for telescopes of focal ratio f / 2.5 or faster.
The focal ratio is more important to the magnification rather than the light collection, and too much magnification will spread out the light from deep-sky objects.
Lowell's large refracting telescope, set at 144X magnification and with an aperture narrowed down that far, they figured, had a focal ratio of at leastf / 120.
This is of particular importance in fish, where the value may decrease from as high as 3.6 to 2.3, decreasing the focal ratio of the accommodate is gained.
The KSAR Telescope's 60-foot diameter steel dome is quite large for the telescope's aperture, owing to its telescope's long f / 9.8 focal ratio ( favorable for very accurate photometry.