Projection objective

A projection objective configured to image an object field in an object plane having a field aspect ratio of at least 1.5 into an image field in an image plane, the projection objective comprising:

• at least two optically effective surfaces configured to guide imaging light in a beam path between the object field and the image field,
• wherein:
• the object field has first and second dimensions that are perpendicular to each other;
• the first dimension of the object field is less than the second dimension of the object field;
• the optically effective surfaces, the object field and the image field take up an installed space having a cuboid envelope;
• the cuboid envelope has a length dimension, a first dimension and a second dimension;
• the first dimension of the cuboid envelope is transverse to the length dimension of the cuboid envelope;
• the second dimension of the cuboid envelope is transverse to the length dimension of the cuboid envelope;
• the first dimension of the cuboid envelope is perpendicular to the second dimension of the cuboid envelope;
• the length dimension of the cuboid envelope is a length of the projection objective between the object plane and the image plane;
• the first dimension of the cuboid envelope is parallel to the first dimension of the object field;
• and
• the first dimension of the cuboid envelope is less than the first dimension of the object field.