On 24/09/15 15:44, NY wrote:

I'm not sure about your autofocus reason though. The speed of autofocus
response will be a function of the camera's AF detector and (for an
interchangeable lens) the speed of the AF motor in the lens. Digital
cameras may have faster AF, but that may because they are newer rather
than because they are digital rather than film. Unless anyone knows
differently in which case I might be about to learn something!

As far as I can remember, my film SLR took about the same time to focus
as the digital SLR which replaced it, using the same lens, which
suggests that, for my setup, most of the time is taken by the motor in
the lens rather than by the AF sensor and logic in the camera. That's
for like-for-like focussing rules - eg single-shot rather than
continuous and similar sizes of focus zone.


For a SLR the time is limited by the speed of the mirror. Both digital
and film SLRs have mirrors and shutters so there is no difference. The
autofocus sensors are separate from the digital image sensor.


--
DJC
(–€Ì¿Ä¹Ì¯–€Ì¿ Ì¿)