Often, the provision of a results image which satisfies one or more optimization criteria may be desirable when imaging objects by means of an optical apparatus. In particular, such an optimization criterion may be an image contrast of the results image. It may be desirable to obtain an image contrast which is as high as possible. In the case of a comparatively high image contrast, it may be possible to obtain very different physical parameters and information about the object.
Techniques (structured illumination) which facilitate such an optimization of the results image by means of appropriate hardware of an illumination apparatus of the optical apparatus are known. By way of example, such techniques are described in H. Gross et al., “Handbook of Optical Systems”, volume 2, Wiley-VCH, 2005. Here, it is possible to use, for example, structure filters in a pupil plane of the illumination apparatus. As a result, it may be possible to image the object, e.g., in particular, an amplitude object, with a particularly great information depth.
However, such techniques have certain restrictions or disadvantages. Since the selection of the structure filter typically depends on the object to be imaged, it may be necessary to receive the structure filter in an interchangeable manner in the illumination apparatus by means of a mask-interchange unit and possibly keep a plurality of different structure filters available. For different types of objects, such as e.g. biological samples or unknown non-biological samples, this may be disadvantageous since it is necessary to keep a relatively large number of structure filters available. What may then happen in practice is that the matching structure filter is not present. Further, a subsequent change of the structure filter after completed image capture (post-processing step) is not possible or only possible to a restricted extent. Typically, the complexity of the optical apparatus increases as a result of keeping additional hardware components available. A susceptibility to errors, for example on account of incorrect mechanical actuation, wear-and-tear or contamination, etc., may also be increased by the interchangeable availability of the structure filters.