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Strange focus cant get any method to focus on it!

Started Oct 7, 2017 | Questions thread
R2D2 Forum Pro • Posts: 26,551
Re: Strange focus cant get any method to focus on it!

WilbaW wrote:

R2D2 wrote:

AF systems typically can have trouble with reds also.

Except for the red light emitted by the AF assist lamps of many Canon flashes, such as the 430s and 580s. (And no, it's not infrared if you can see it. )

True.  Although I've never liked using those AF assist lamps.  Canon makes the lights red to (attempt to) lessen how annoying they are, but still, talk about ruining spontaneity!  Plus most systems I've used force you to use multi-point AF instead of a single point (there goes all user input for focus point!).  In addition their range is still quite limited (think clouds) and you gotta keep that big ol' flash on top of the camera all the time.  Ugh. 

And infrared (and even near-infrared) aren't used because they would totally screw up today's autofocus systems due to the different wavelengths involved.  All images would be OOF.  Harken back to the days of shooting infrared film, and the focusing work-arounds needed (you and I are certainly old enough, LOL  ).

In addition the IR cut filter over these digital image sensors would completely block the IR wavelengths anyway, rendering even sensor-based AF systems useless.  Whew, rant is now over 

Hmmm, how about an active microwave laser radar AF system though...

Nah, it'd toast your frontal lobes for sure.

Oh well, it's back to using good technique...

Cheers,

R2 

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