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Old Jan 24, 2007, 6:11 PM   #1
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I have an istDS that I am generally happy with. However the autofocus speed in moderate and low light (e.g average incandescent room light) is really slow. The camera flickers the flash to assist but it still often takes several seconds (e.g 6-7 secs) to acheive focus and then is often poorly focused in the end. Is this a common issue with this camera?
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Old Jan 24, 2007, 7:29 PM   #2
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Depends on the lens and how little light there is. I generally switch to MF when my lenses hunt a lot. Another trick is to prefocus on a high contrast area of the room which is more or less the same ditance from the camera as your subject.

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Old Jan 24, 2007, 7:55 PM   #3
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Try switching to center point AF and zoom to the widest setting the lens will go(this will let the most light to the sensor). I own an ist DL and purchased the AF360FGZ flash to help with AF in low light. It uses an IR grid projected onto your subject and focus speed is much faster. You can turn off flash and use the AF assist only if you want ambient light. The ist models are known for their low light focusing problems, but the newer models are much better. Hope this helps.
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Old Jan 25, 2007, 1:22 AM   #4
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Yup lens and it wide open F stop is absolutely a factor....

But then again another place the K10D astounds me.... darn well and fast AF in low light.

In fact manual says if needed it will stobe the flash, but when flash up and active I have YET to have that actually happen, even in places avail light it would be like 1/2 sec or more exposure at 400. So it is both lens and camera caliber issues.

Also just got a 1.5 extender for my SIGMA 70-300mm lens.... cuts 1+ stops and only a F4-5.6 lens.... Tameron says.... for the extender wide open lens must be 2.8 or better for AF to be reliable.... yet NO noticeable AF problems (vs extender off) on the K10D... 1-2 stops lower than Tameron's recomendation. (And mostly 2 as I tend to use that lens at/towards full zoom
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