Ultra–large field-of-view two-photon microscopy
... The design of the scan system begins with the selection of the objective. We seek a field-ofview that encompasses 10 mm, a numerical aperture (NA) to achieve 1-µm resolution, and a back aperture that does not exceed 25 mm. The singular choice is a 4-times magnification (f = 45 mm), 0.28 NA air-immer ...
... The design of the scan system begins with the selection of the objective. We seek a field-ofview that encompasses 10 mm, a numerical aperture (NA) to achieve 1-µm resolution, and a back aperture that does not exceed 25 mm. The singular choice is a 4-times magnification (f = 45 mm), 0.28 NA air-immer ...
Relating axial motion of optical elements to focal shift
... NAim = numerical aperture in the image plane m = magnification of the element These equations are valid for small motions and the amount of error from actual focal shift decreases proportional to 1/(f/#)2 of an element. Determining the amount of wavefront error due to defocus was also presented. Th ...
... NAim = numerical aperture in the image plane m = magnification of the element These equations are valid for small motions and the amount of error from actual focal shift decreases proportional to 1/(f/#)2 of an element. Determining the amount of wavefront error due to defocus was also presented. Th ...
PPT
... – dark adapted pupil up to 7 mm diameter (2–3 mm in daylight) – sets limit on minimum magnification (if you want to use the full aperture) • 210 mm aperture telescope must have M > 30 • for f/5 scope, means f2 < 35 mm; f/10 scope means f2 < 70 mm • 3.5-m scope means M > 500; at f/10, f2 < 70 mm Spri ...
... – dark adapted pupil up to 7 mm diameter (2–3 mm in daylight) – sets limit on minimum magnification (if you want to use the full aperture) • 210 mm aperture telescope must have M > 30 • for f/5 scope, means f2 < 35 mm; f/10 scope means f2 < 70 mm • 3.5-m scope means M > 500; at f/10, f2 < 70 mm Spri ...
GGN PUBLIC SCHOOL, LUDHIANA XII PHYSICS ASSIGNMENT
... 2. The radius of curvature of the faces of a double concave lens are 10cm and 15 cm. if focal length is 12 cm, what is the refractive index of the glass?[1.5] 3. A biconvex lens has a focal length half the radius of curvature of either surface. What is the refractive index of lens material? [2] 4. T ...
... 2. The radius of curvature of the faces of a double concave lens are 10cm and 15 cm. if focal length is 12 cm, what is the refractive index of the glass?[1.5] 3. A biconvex lens has a focal length half the radius of curvature of either surface. What is the refractive index of lens material? [2] 4. T ...
Aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. The aperture determines how collimated the admitted rays are, which is of great importance for the appearance at the image plane. If an aperture is narrow, then highly collimated rays are admitted, resulting in a sharp focus at the image plane. If an aperture is wide, then uncollimated rays are admitted, resulting in a sharp focus only for rays with a certain focal length. This means that a wide aperture results in an image that is sharp for things at the correct distance. The aperture also determines how many of the incoming rays are actually admitted and thus how much light reaches the image plane (the narrower the aperture, the darker the image for a given exposure time). In the human eye, the pupil is the aperture.An optical system typically has many openings, or structures that limit the ray bundles (ray bundles are also known as pencils of light). These structures may be the edge of a lens or mirror, or a ring or other fixture that holds an optical element in place, or may be a special element such as a diaphragm placed in the optical path to limit the light admitted by the system. In general, these structures are called stops, and the aperture stop is the stop that determines the ray cone angle, or equivalently the brightness, at an image point.In some contexts, especially in photography and astronomy, aperture refers to the diameter of the aperture stop rather than the physical stop or the opening itself. For example, in a telescope the aperture stop is typically the edges of the objective lens or mirror (or of the mount that holds it). One then speaks of a telescope as having, for example, a 100 centimeter aperture. Note that the aperture stop is not necessarily the smallest stop in the system. Magnification and demagnification by lenses and other elements can cause a relatively large stop to be the aperture stop for the system.Sometimes stops and diaphragms are called apertures, even when they are not the aperture stop of the system.The word aperture is also used in other contexts to indicate a system which blocks off light outside a certain region. In astronomy for example, a photometric aperture around a star usually corresponds to a circular window around the image of a star within which the light intensity is assumed.