Effect of Focus Error and Spherical Aberration on Sharp Edge Image Intensity
The "Effect of Focus Error and Spherical Aberration on Sharp Edge Image Intensity" refers to a study or experiment that explores the impact of focus error and spherical aberration on the intensity of an image of a sharp edge.
Focus error refers to the degree to which an optical system, such as a camera or microscope, is able to focus on a particular point or object. Spherical aberration, on the other hand, is an optical defect that causes a lens to produce images that are blurry or distorted.
The study may involve the use of various optical instruments, such as lenses, cameras, or microscopes, to examine the intensity of images produced under different conditions of focus error and spherical aberration. The sharp edge image may be created using a test pattern or a physical object with a sharp boundary, such as a knife edge or a metal wire.
The results of the study may provide insight into the limitations and potential sources of error in optical imaging systems. For example, the study may reveal that certain types of lenses or camera settings are more susceptible to focus error or spherical aberration, which could help researchers and engineers to improve the design and performance of these instruments.
Overall, the "Effect of Focus Error and Spherical Aberration on Sharp Edge Image Intensity" is an important area of research for anyone who is interested in understanding the principles of optical imaging and improving the quality of images produced by optical instruments.
many researches have been carried out to determine the distribution of the intensity in the image of object with a Sharp-Edge using coherent illumination. In this research, a special formula has been derived called the Edge spreads Function (ESF). This formula is very useful for theoretical and practical studies since it is applicable to system with any kind and number of aberrations that are present in the optical systems by using pupil function technique. Also, optimum balance values for each kind of aberration were determined, these values have been used in programs prepared specially for calculating (ESF) using quick basic programming language with Simpson method for numerical integrals in order to calculate the intensity of different quantities of aberrations such as focus error and spherical aberration (first, Third, fifth – orders). As well as the effect of Apodization upon the image of sharp
Edge object resulting from an optical system operating with a small circular aperture. The main aim of this research is testing the Optical Systems which use Coherent light and make decision of this Systems validity range. we found that using the exit pupil technique is useful to calculate the complex intensity also the analysis capability when using coherent light is better than the incoherent light and the relation between the focus error and the quantity of aberration.
Some conclusions about the aberrations:
1. Finding the complex amplitude in the image of a sharp edge body can be in terms of the exit pupil f (x), and not only in terms of (Optical Transfer Function).
2. Analysis capability when using coherent light is better than the incoherent light.
3. Focal error depends on the change in the kind and quantity of aberration.
4. In optimum situation for coherent illumination when (W20 = - o.86l) then (W40 =1l).
5. The tolerance in focus error is (w20 ≤ 0.25) in order to keep the same image quality.
6. The spherical aberrations of fifth order is less effect on the sharpness of the image than the spherical aberrations of the third order.