Canon SX10 IS Viewfinder is Blurry

On the left of the viewfinder, there is a little wheel. That is the diopter adjustment, which must be adjusted for your eyes. Rotate the wheel until things look in focus when you look through the viewfinder. The diopter wheel on the SX10 IS is prone to move when you take your camera in and out of the case, so it may need readjustment regularly.

If the image is blurred on both clean the lens, if it does not fix it then it is probably a faulty lens problem.

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you have adjust diaptor wheel acoording to your eye setting. adjust your camera according to this sujetion you want get blurry picture.
you can get this diaptor wheel next to view finder.

Check the diopter adjustment on the left side of the viewfinder.

If the viewfinder is also blurry, it might be as simple as a smudge on the lens. Is the blur uniform and consistent on the pictures and in the viewfinder? Was there a curious dog nearby when you set the camera down?:)

See this link.

It will clear instantly with a fresh battery.

The viewfinder screen has an LCD overlay and even when the camera is switched off the screen uses a small amount of power. When the batteries are flat the screen is unpowered, the crystals in the LCD align randomly to both darken and blur the viewfinder image.

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There is a little knob to the left of the viewfinder called the diopter adjustment. Turn that.

There's a little scrolling wheel to the left of the viewfinder; move it up or down until the image is clearest.