There are some stains on the shutter of the ILCE-1

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The streaky lines and/or smears that appear when the shutter curtain is closed are patterns made by the carbon material used in the shutter blades.
Due to individual differences, the markings may be more noticeable on some cameras than depicted in this image, depending on the direction of viewing.

These markings are patterns from the material, and does not affect the camera performance.

• When viewed from the front
  
• When viewed from above at an angle