The picture should sharply focus on the face of the applicant and should have a strong contrast. Poor colored picture or blurred pictures are not acceptable
The brightness level of the picture is to be maintained. The picture should spread even light on the face of the person. There should be no red eye, over whiteness or reflection in the picture.
The ideal background for a picture is neutral grey color as it gives the right amount of contrast to the face and even level of brightness is maintained. A colorful, patterned or shadow background is not acceptable for the pictures required for Schengen Visa.
The picture should be printed on a paper with high quality a minimum of 600 dpi should be there. There should be a natural skin tone in the picture. Layers and creases or spots should not be present.
The face should be straight as eyes should focus on the camera. Head should not be tilted to any direction. There should be normal expressions of face. Widened mouth or a big smile is not required for the picture.
It is very important that your eyes are opened properly in the picture. No hair should be falling on your eyes and the focus of your eyes should be directly towards the camera.
For getting a picture clicked sunglasses or even optical glasses should be avoided. If you are wearing glasses, then frame should be such that your eyes are clearly visible.
Caps, hats or any other kind of headwear should be avoided as they pose reflection in the picture. There are few exceptions for the people who wear religious headwear but even that should be such that clear face from the forehead to the lower tip of the chin is visible.
These are some of the points which one must keep in mind while getting a picture clicked for Schengen Visa.
All the best!!