The effect of longitudinal chromatic aberration on the lag of accommodation and depth of field

2016 ◽  
Vol 36 (6) ◽  
pp. 657-663 ◽  
Author(s):  
Mateusz Jaskulski ◽  
Iván Marín-Franch ◽  
Paula Bernal-Molina ◽  
Norberto López-Gil
Keyword(s):  
Chromatic Aberration ◽  
Depth Of Field ◽  
Lag Of Accommodation

400 Kv Electron Cryo-Microscopic Imaging Of Large Icosahedral Viruses Towards Atomic Resolution

1999 ◽  
Vol 5 (S2) ◽  
pp. 186-187
Author(s):  
Joanita Jakarta ◽  
Wah Chiu
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Clinical Manifestations ◽  
Image Data ◽  
Chromatic Aberration ◽  
Dimensional Structure ◽  
Depth Of Field ◽  
Periodic Arrays ◽  
Icosahedral Viruses ◽  
Simplex Virus

Three-dimensional structure studies provide important information about the organization of macromolecules, often revealing biological mechanisms and protein structure-function relationships. 400 KV electron cryo-microscopy is an emerging technology that is proving to be a powerful tool for studying the structures of large macromolecular assemblies that are often not tractable using other techniques. Its large depth of field makes it well-suited for imaging large objects to high resolution. In addition, a high accelerating voltage minimizes chromatic aberration yielding images of higher contrast. Recently a 400 KV electron cryo-microscope has been used to image periodic arrays of tubulin to 3.5 Å and single particles at somewhat lower resolutions (13 Å) providing practical demonstrations of its usefulness in modern structural biology. In this paper we present high resolution image data of two large icosahedral viruses: herpes simplex virus IB nucleocapsid (HSV IB) and rice dwarf virus (RDV). Human herpes virus (HSV) is associated with a spectrum of diseases ranging from cold sores to more severe clinical manifestations such as mental retardation.

scholarly journals A New Method for Conservation of Ancient Colored Drawing on Hemp Textiles

2020 ◽  
Author(s):  
Jiaojiao Liu ◽  
Yuhu Li ◽  
Huiping Xing ◽  
Daodao Hu ◽  
Xiaolian Chao ◽  
...  
Keyword(s):  
Uv Light ◽  
Chromatic Aberration ◽  
Element Distribution ◽  
Depth Of Field ◽  
Conservation Treatment ◽  
Before And After ◽  
Wet Heat ◽  
Historical Culture ◽  
Restoration And Protection ◽  
Cultural Relics

Abstract As a kind of textile, hemp artifact is a valuable cultural heritage. Suffering from several degradation factors in the preservation of cultural relics, some ancient hemp colored-paintings have been damaged, further affected their ornamental values. Therefore, it is urged to take the suitable conservation measures to protect the precious hemp artifacts for the historical culture succession. In this paper, an examination and analysis of the hemp colored paintings were the first step to propose an appropriate conservation treatment. Ultra-depth-of-field microscope was used to identify the kinds of fiber, and scanning electron microscope (SEM) was utilized to observe their condition and surface morphology. The element distribution and composition were identified by SEM, energy disperse spectroscopy (EDS) and X-ray fluorescence spectroscopy (XRF). Gas chromatography-mass spectrometer (GC-MS) was applied to identify the kinds of binding media and amino acid composition. Moreover, novel reinforcement materials and technology were proposed with the principle of compatibility and feasibility. The properties of tensile strength, aging resistance and chromatic aberration were tested before and after dry heat aging, wet heat aging and UV light aging. After systematic examination and evaluation of the hemp colored paintings and reinforcement materials, the optimal conservation treatment was finally established, and the Chinese hemp painting as an example has been protected successfully. This paper provides new methods and ideas for the restoration and protection of the linen cultural relics, which would promote the progress of protecting valuable cultural heritages.

scholarly journals Extending the depth of field with chromatic aberration for dual-wavelength iris imaging

2017 ◽  
Vol 25 (25) ◽  
pp. 31696 ◽  
Author(s):  
Niamh M. Fitzgerald ◽  
Christopher Dainty ◽  
Alexander V. Goncharov
Keyword(s):  
Chromatic Aberration ◽  
Dual Wavelength ◽  
Depth Of Field

scholarly journals GEOMETRIC DISTORTION OF HISTORICAL IMAGES FOR 3D VISUALIZATION

2020 ◽  
Vol V-2-2020 ◽  
pp. 649-655
Author(s):  
E. Paiz-Reyes ◽  
M. Brédif ◽  
S. Christophe
Keyword(s):  
3D Visualization ◽  
Image Plane ◽  
Chromatic Aberration ◽  
Geometric Distortion ◽  
Depth Of Field ◽  
Mathematical Function ◽  
Field Variation ◽  
Image Domain ◽  
Original Photograph ◽  
3D Scene

Abstract. Archivists, historians and national mapping agencies, among others, are archiving large datasets of historical photographs. Nevertheless, the capturing devices used to acquire these images possessed a diversity of effects that influenced the quality of the final resulting picture, e.g. geometric distortion, chromatic aberration, depth of field variation, etc. This paper examines singularly the topic of geometric distortion for a co-visualization of historical photos within a 3D model of the photographed scene. A distortion function of an image is ordinarily estimated only on the image domain by adjusting its parameters to observations of point correspondences. This mathematical function may exhibit overfits, oscillations or may not be well defined outside of this domain. The contribution of this work is the description of a distortion model defined on the whole undistorted image plane. We extrapolate the distortion estimated only on the image domain and then transfer this distortion information to the view of the 3D scene. This enables to look at the scene through an estimated camera and zoom out to see the context around the original photograph with a well-defined and behaved distortion. These findings may be a significant addition to the overall purpose of creating innovative ways to examine and visualize old photographs.

Optical Profilometry as a Non-Destructive Technique to Quantify Engraving on Medieval Brass Astrolabes

2004 ◽  
Vol 852 ◽  
Author(s):  
Brian D. Newbury ◽  
Michael R. Notis
Keyword(s):  
White Light ◽  
Chromatic Aberration ◽  
Lateral Resolution ◽  
Depth Of Field ◽  
Scientific Instrument ◽  
Vertical Resolution ◽  
Optical Profilometry ◽  
Surface Features ◽  
Non Destructive

ABSTRACTOptical profilometry has been performed on an astrolabe dated 1556 AD and attributed to the famous maker Gualterus Arsenius of Louvain, Belgium. In this non-destructive technique, a beam of white light is impinged on the sample and combined with the chromatic aberration technique to accurately measure surface features. With machine parameters set to a vertical resolution of 0.1 μm, lateral resolution to 6 μm and a 3 mm depth of field, various engraving features on the astrolabe were studied. Both hand-scribed and stamped markings are present on the astrolabe components. Inspection of the hand-scribed date on the instrument's mater allows one to quantify the shape and dimensions of the tool used, as well as the direction and inclination of the engraving tool during inscription. The results of this analysis give information about how the astrolabe was constructed in one of the Renaissance's greatest scientific instrument workshops. The results are compared to similar engravings on an undated and unsigned Islamic astrolabe tympan.

scholarly journals Power Phase Apodization Study on Compensation Defocusing and Chromatic Aberration in the Imaging System

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1327
Author(s):  
Svetlana N. Khonina ◽  
Sergey G. Volotovskiy ◽  
Alexey P. Dzyuba ◽  
Pavel G. Serafimovich ◽  
Sergey B. Popov ◽  
...  
Keyword(s):  
Imaging System ◽  
Color Image ◽  
Chromatic Aberration ◽  
Spot Size ◽  
Light Spot ◽  
Depth Of Field ◽  
Nonlinear Relationship ◽  
Point Spread ◽  
Spread Function ◽  
High Degree

We performed a detailed comparative study of the parametric high degree (cubic, fourth, and fifth) power phase apodization on compensation defocusing and chromatic aberration in the imaging system. The research results showed that increasing the power degree of the apodization function provided better independence (invariance) of the point spread function (PSF) from defocusing while reducing the depth of field (DOF). This reduction could be compensated by increasing the parameter α; however, this led to an increase in the size of the light spot. A nonlinear relationship between the increase in the DOF and spot size was shown (due to a small increase in the size of the light spot, the DOF can be significantly increased). Thus, the search for the best solution was based on a compromise of restrictions on the circle of confusion (CoC) and DOF. The modeling of color image formation under defocusing conditions for the considered apodization functions was performed. The subsequent deconvolution of the resulting color image was demonstrated.

Design of objective lens for 200-kV high-resolution electron microscopes

1983 ◽  
Vol 41 ◽  
pp. 314-315
Author(s):  
K. Tsuno ◽  
T. Honda ◽  
Y. Harada ◽  
M. Naruse
Keyword(s):  
Optical Properties ◽  
Computer Technology ◽  
Axial Magnetic Field ◽  
Chromatic Aberration ◽  
Objective Lens ◽  
Resolution Electron ◽  
Correction Of Astigmatism ◽  
Three Stages ◽  
Electron Microscopes ◽  
Stage 1

Developement of computer technology provides much improvements on electron microscopy, such as simulation of images, reconstruction of images and automatic controll of microscopes (auto-focussing and auto-correction of astigmatism) and design of electron microscope lenses by using a finite element method (FEM). In this investigation, procedures for simulating the optical properties of objective lenses of HREM and the characteristics of the new lens for HREM at 200 kV are described.The process for designing the objective lens is divided into three stages. Stage 1 is the process for estimating the optical properties of the lens. Firstly, calculation by FEM is made for simulating the axial magnetic field distributions Bzc of the lens. Secondly, electron ray trajectory is numerically calculated by using Bzc. And lastly, using Bzc and ray trajectory, spherical and chromatic aberration coefficients Cs and Cc are numerically calculated. Above calculations are repeated by changing the shape of lens until! to find an optimum aberration coefficients.

Resolution, Contrast and Interpretation of HVEM Images of Crystals

1973 ◽  
Vol 31 ◽  
pp. 228-229
Author(s):  
L. E. Thomas ◽  
J. S. Lally ◽  
R. M. Fisher
Keyword(s):  
High Voltage ◽  
Chromatic Aberration ◽  
Crystalline Materials ◽  
Resolution Parameter ◽  
Instrument Resolution ◽  
Imaging Conditions ◽  
Beam Excitation ◽  
Optimum Imaging

In addition to improved penetration at high voltage, the characteristics of HVEM images of crystalline materials are changed markedly as a result of many-beam excitation effects. This leads to changes in optimum imaging conditions for dislocations, planar faults, precipitates and other features.Resolution - Because of longer focal lengths and correspondingly larger aberrations, the usual instrument resolution parameter, CS174 λ 374 changes by only a factor of 2 from 100 kV to 1 MV. Since 90% of this change occurs below 500 kV any improvement in “classical” resolution in the MVEM is insignificant. However, as is widely recognized, an improvement in resolution for “thick” specimens (i.e. more than 1000 Å) due to reduced chromatic aberration is very large.

The Resolution and Contrast in Biological Sections Determined by Inelastic and Elastic Scattering

1973 ◽  
Vol 31 ◽  
pp. 224-225
Author(s):  
D. L. Misell
Keyword(s):  
Electron Microscopy ◽  
Adverse Effect ◽  
Elastic Scattering ◽  
Inelastic Scattering ◽  
Amorphous Carbon ◽  
Polymeric Materials ◽  
Chromatic Aberration ◽  
Image Resolution ◽  
Quantitative Estimates ◽  
Elastic Ratio

In the electron microscopy of biological sections the adverse effect of chromatic aberration on image resolution is well known. In this paper calculations are presented for the inelastic and elastic image intensities using a wave-optical formulation. Quantitative estimates of the deterioration in image resolution as a result of chromatic aberration are presented as an alternative to geometric calculations. The predominance of inelastic scattering in the unstained biological and polymeric materials is shown by the inelastic to elastic ratio, I/E, within an objective aperture of 0.005 rad for amorphous carbon of a thickness, t=50nm, typical of biological sections; E=200keV, I/E=16.

Sign in / Sign up

Export Citation Format

Share Document