The main difference between a lens with an aperture of f1.4 and a lens with an aperture of f1.8 is the amount of light that can enter the lens. A lens with an aperture of f1.4 allows more light to enter compared to a lens with an aperture of f1.8. This means that the f1.4 lens can produce brighter images and is better suited for low-light conditions. Additionally, a lens with a wider aperture like f1.4 can create a shallower depth of field, resulting in more pronounced background blur or bokeh in photographs.
The F4 Phantom II did over 1,500 mph. If you meant F14 that was a post Viet War jet called the F14 Tomcat.
Tomcat
f14
F14
Mach 2.34 (1,544mph)
F13 = {Shift Key}+F1 F14 = {Shift Key}+F2 F15 = {Shift Key}+F3 etc.
F14 Tomcat
Formula
f14 tomcat
Grumman Aerospace built the F-14
The F-14 could fly to altitudes of about 50,000ft
The Tomcat's top speed is about 1,550 mph