Saturday, August 8, 2009

HX1 focus error - why do blurs suddenly appear

every time you are near?
No, I am not drunk, was just thinking of Karen Carpenter  wondering why a shot was blurry (out of focus) in an area where the HX1 showed it had a focus lock.

On closer inspection the HX1 did focus instead of a line and the telephone pole.
Well the way I remembered focus was, that everything after 10 meters is kind of infinity.Now the line in the picture is roughly 30 meters away while the golfers are between 150-200 meters. The focus lock did show the people and not the pole or the line.

On manual focus set to infinity the picture is sharp where it is supposed to be.

Setting manual focus on step less, where it should focus on the line, every thing is blurred.
Now we are more in the area of: why do blur suddenly appear - every time I drink beer....
Let´s investigate this further, shall we?
 Same setting (one step away from infinity and aperture to the max f8

The line is a bit clearer but it is all still out of focus.

So how about f8 and infinity?

Golfers sharp line slightly out of focus.
With focus set to center focus the camera focuses right on the golfers and avoids the cable and pole.

What will happen if we use SONY´s Semi Manual focus?
(Auto focus approximately at preset distance)
Set to infinity,  focus lock on the pole and next to the pole

now the mountain is sharp.
One step less than infiniti same and all is blurry again: (No need to show another blurry foto)
Focus lock is then roughly in an area from 8 meter

to 20 meters

In manual focus there are 11 steps between 2 meter and infinity.
Reminder: In case of doubt, check in playback with maximal magnification and better shoot another one to be sure . Face detection is off in center focus mode.
Conclusion: The auto focus has much more steps to focus than the manual mode and with zoom to 20x there are several focus points between 10 meter and infinity.

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