Auto focus sensor at DVinfo.net

Philip Younger · July 23rd, 2009, 10:02 AM

I was shooting with autofocus, using a matt box, when I realised that the matt box cut out the autofocus sensor - yet autofocus still worked.

In the book of wisdom (the manual) it refers to the sensor as "External sensor for the instant AF - page 33" but page 33 still left me defeated, can anyone explain exactly what this 'external sensor..." does?

Ken Wozniak · July 23rd, 2009, 01:29 PM

The sensor is for the Instant Auto Focus (IAF). It's meant to supplement the normal TTL autofocus method, allowing for quicker focus on subjects.

The IAF sensor can be turned off, and should be turned off when using accessories that interfere with the sensor.

Philip Younger · July 23rd, 2009, 04:10 PM

Thanks Woz.

July 23rd, 2009, 10:02 AM	#1
Philip Younger Major Player Join Date: May 2008 Location: Warwickshire Posts: 207	Auto focus sensor I was shooting with autofocus, using a matt box, when I realised that the matt box cut out the autofocus sensor - yet autofocus still worked. In the book of wisdom (the manual) it refers to the sensor as "External sensor for the instant AF - page 33" but page 33 still left me defeated, can anyone explain exactly what this 'external sensor..." does?

July 23rd, 2009, 01:29 PM	#2
Ken Wozniak Regular Crew Join Date: May 2007 Location: South Bend, IN Posts: 179	The sensor is for the Instant Auto Focus (IAF). It's meant to supplement the normal TTL autofocus method, allowing for quicker focus on subjects. The IAF sensor can be turned off, and should be turned off when using accessories that interfere with the sensor. __________________ Woz

July 23rd, 2009, 04:10 PM	#3
Philip Younger Major Player Join Date: May 2008 Location: Warwickshire Posts: 207	Thanks Woz.