SUMMARY
Photographers often obsess over ultra-fast lenses like f/1.4, f/1.2, or f/0.95, driven by the pursuit of extreme subject separation and low-light performance. However, analysis of personal shooting data often reveals these expensive lenses are frequently used at smaller apertures like f/2.8, f/4, or f/8. For most, an f/2.8 aperture provides ample light and depth of field, especially with modern cameras' high ISO capabilities and sensible shutter speed choices. Ultra-fast lenses come with compromises in size, weight, cost, and extremely narrow depth of field, sometimes performing best when stopped down anyway.
TAKEAWAYS
Many photographers overvalue ultra-fast f/1.4 lenses, often using them at smaller apertures.
f/2.8 is generally sufficient for most photographic needs, including low light.
Ultra-fast lenses are larger, heavier, more expensive, and have very shallow depth of field.
Focus on actual shooting habits rather than chasing lens specifications.