# AF assist for outer focus points on 5D3?



## skitron (Jan 17, 2013)

Do flashes with AF assist only project a beam for center focus point use or do some models allow use of the outer points as well? If the latter, which models? Thanks in advance for any info shared!


----------



## digital paradise (Jan 17, 2013)

Yes they do to some degree and I know the 600EX-RT patterns are designed to work with the 5D3.


----------



## neuroanatomist (Jan 17, 2013)

I previously tested the AF assist lamp coverage of the 430EX II with the 61-pt AF system of the 1D X (and 5DIII). With a focal length of wider than 35mm, the outermost columns (which are f/5.6-sensitive lines) are outside of the coverage area. At 35mm and longer focal lengths, the 430EX II's assist lamp covers all 61 points. 

The 600EX-RT provides full coverage, of course.


----------

