FTM

Question

How do I use Full Time Manual (FTM) focusing with my Canon 85mm 1.8 lens?

Canon lens manual says to “press the shutter button halfway and turn the focusing ring”. Is it necessary to press the shutter halfway as stated by manual? I have done FTM focusing with and without pressing the shutter halfway. FTM works fine without pressing the shuter halfway. But when I pressed the sutter halfway and use FTM, lens made a grinding noise - like changing gears. Is this normal? Why bother pressing shutter halfway when FTM focusing can be done without pressing the shutter? BTW this is a new lens.Also, is it OK to mount a cheap rubber hood ($3 hood)on the UV filter attached to my Canon 85mm 1.8 lens?

Answers

You can flip the AF/MF switch on the lens to MF and focus manually forever without any problems. “Full Time Manual Focusing”, as referred to in the EF lenses with USM motors, however, means you can manually adjust focus after autofocusing. Press the button, let the lens focus and then adjust focus with the manual focusing ring without lessening pressure on the shutter release. No need to flip the AF/MF switch. Be sure the camera is set to One Shot focusing. If you’re set on AI Focus or AI Servo, the lens will try to continue to autofocus while you’re trying to manually adjust focus. It sounds as if you’re probably set on AI Focus/AI Servo if you’re getting a grinding noise. That’s the internal autofocus mechanism eating itself up as it tries to fight back your attempt so manually focus.

Cheap rubber lens hoods don’t look cool. But they are better than nothing if you need a lens hood.