What is a Parfocal Lens? Every zoom lens is a compromise. For a given focal length and aperture combination, a prime (or block) lens offers the greatest freedom to a lens designer. Every element in such a ... Read more →
What is a Parfocal Lens? Every zoom lens is a compromise. For a given focal length and aperture combination, a prime (or block) lens offers the greatest freedom to a lens designer. Every element in such a ... Read more →