Manual focus differences: DSLR vs mirrorless cameras

Canon EOS SOS Manual Focus
Full-time manual focus is used to pre-focus the lens so your camera isn’t hunting for focus when the subject appears in the frame (Image credit: Brian Worley)

A key defining principle of the Canon EOS DSLR camera system was to make it simple and instinctive. Full-time manual focus for lenses with USM focus motors fits that remit. It is useful for subjects that don’t move a great deal; the ability to simply turn the lens’ focus ring if shooting macro or landscapes was so instinctive that you might not even have realized that it was a designed feature. It also means that the lens can be manually pre-focused before you even start the AF. 

When EF lenses for DSLRs were introduced with fly-by-wire focus rings, new custom settings were added to the cameras to still enable focus to be adjusted slightly once One-Shot AF was complete. 

PhotoPlus: The Canon Magazine

PhotoPlus: The Canon Magazine is the world's only monthly newsstand title that's 100% devoted to Canon, so you can be sure the magazine is completely relevant to your system. Every issue comes with downloadable video tutorials too. 

Thank you for reading 5 articles this month* Join now for unlimited access

Enjoy your first month for just £1 / $1 / €1

*Read 5 free articles per month without a subscription

Join now for unlimited access

Try first month for just £1 / $1 / €1

Brian Worley

Brian is a freelance photographer and photo tutor, based in Oxfordshire. He has unrivaled EOS DSLR knowledge, after working for Canon for over 15 years, and is on hand to answer all the EOS and photographic queries in Canon-centric magazine PhotoPlus.