Transmissive dark-field illumination method for high-accuracy automatic lace scalloping

2006 ◽  
Vol 32 (5-6) ◽  
pp. 599-607 ◽  
Author(s):  
P. E. Bamforth ◽  
M. R. Jackson ◽  
K. Williams
Keyword(s):  
High Accuracy ◽  
Dark Field ◽  
Dark Field Illumination ◽  
Illumination Method

Resolving Low-Contrast Microstructure Using Transmitted and Reflected Circular Oblique Lighting (COL)

2012 ◽  
Vol 20 (3) ◽  
pp. 38-41 ◽  
Author(s):  
Ted Clarke
Keyword(s):  
Numerical Aperture ◽  
Dark Field ◽  
Resolution Limit ◽  
Hollow Cone ◽  
Bright Field ◽  
Low Contrast ◽  
Dark Field Illumination ◽  
Illumination Method ◽  
Favorable Conditions ◽  
Electron Lithography

A little-known illumination method for light microscopy goes by several names, the most prominent being “circular oblique lighting” (COL) and “hollow-cone illumination”. Matthews notes that hollow-cone or annular bright field illumination can give contrast and resolution superior to that obtainable with narrow-pencil illumination and under favorable conditions comparable to that obtained with phase optics. He demonstrates this with photomicrographs of the same unstained epithelial cell from the mouth mounted in saliva, imaged with a 0.65 numerical aperture (NA) 40× objective. Matthews also notes that the dot pattern of Pleurosigmaangulatum can be resolved with a 0.50 NA objective using circular oblique lighting. Leitz previously marketed the Heine illuminator for transmitted annular (hollow cone) illumination. The NA of the Heine condenser's annular illumination can be adjusted to match the phase annuli in phase contrast objectives. The NA can be increased to provide dark field illumination or circular oblique illumination in bright field. The instructions for the Heine condenser call for the annular illumination just falling within the NA of the objective, what Paul James calls COL and Frithjof A. S. Sterrenberg calls extreme annular illumination, “bright field with very rich contrast.” H. J. Dethloff published a more recent article describing the need for the increased contrast of hollow cone bright field to help resolve the striae of pores in the diatom Amplipleurapellucida. This diatom has been the traditional test of the resolution limit of the light microscope; it is considered a low-contrast subject because the visibility of pores in the transparent amorphous silica frustules is determined by the refractive index difference between the mountant and the frustules. The low contrast makes this a challenging, perhaps even unsuitable, test object for resolution. Resolution tests of modern objectives are done with high-contrast but costly patterns of chrome on glass obtained by electron lithography.

scholarly journals Dark-field microscopy enhance visibility of CD31 endothelial staining

2020 ◽  
Vol 64 (3) ◽  
Author(s):  
Eva Jennische ◽  
Stefan Lange ◽  
Ragnar Hultborn
Keyword(s):  
Phase Contrast ◽  
Scattered Light ◽  
Dark Field ◽  
Light Scatter ◽  
Endothelial Lining ◽  
Microscopy Technique ◽  
Dark Field Microscopy ◽  
Dark Field Illumination ◽  
Normal Human ◽  
Intense Light

A simple dark field microscopy technique was used for visualization of blood vessels in normal human renal tissues and carcinoma. Phase contrast condenser ring apt for high power objectives was combined with a 10x objective in order to create a dark field illumination of the specimens examined. The endothelial lining of the vessels had been stained by using CD31 monoclonal antibodies combined with conventional peroxidase immunohistochemistry. The final DAB addition used for this technique induced an intense light scatter in the dark field microscope. This scattered light originating from the endothelial lining made the walls of the bright vessels easily detectable from the dark background.

Manipulation of Nanoparticles Using Dark-Field-Illumination Optical Tweezers with Compensating Spherical Aberration

2009 ◽  
Vol 26 (6) ◽  
pp. 068701 ◽  
Author(s):  
Zhou Jin-Hua ◽  
Tao Run-Zhe ◽  
Hu Zhi-Bin ◽  
Zhong Min-Cheng ◽  
Wang Zi-Qiang ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Spherical Aberration ◽  
Dark Field ◽  
Dark Field Illumination

A search for apatite crystals in the gap zone of collagen fibrils in bone using dark-field illumination

Bone ◽  
2020 ◽  
Vol 135 ◽  
pp. 115304 ◽  
Author(s):  
H.P. Schwarcz ◽  
D.M. Binkley ◽  
L. Luo ◽  
K. Grandfield
Keyword(s):  
Dark Field ◽  
Collagen Fibrils ◽  
Apatite Crystals ◽  
Dark Field Illumination

Resistance to cracking of a stretchable semiconductor: Speed of crack propagation for varying energy release rate

2003 ◽  
Vol 795 ◽  
Author(s):  
Sheng Liu ◽  
Hee C. Lim ◽  
Min Qu ◽  
John F. Federici ◽  
Gordon A. Thomas ◽  
...  
Keyword(s):  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
High Speed ◽  
Crack Formation ◽  
Dark Field ◽  
Uniaxial Tensile ◽  
Parallel Lines ◽  
Dark Field Illumination ◽  
Rate Threshold

ABSTRACTWe have measured and calculated the propagation velocity of successive cracks in a single sample of amorphous SiNx as a function of energy release rate. We have obtained the conditions for controlled, repetitive crack formation by using a substrate of compliant plastic that survives the cracking of a thin film formed on it. We have recorded the crack velocity curves using high-speed micro-photography using dark field illumination. Under uniform, uniaxial tensile strain, the films crack in an array of essentially straight, parallel lines, if the increase of the strain density is slow. We find reasonable agreement in the comparison of theory and experiment and find a linear relationship between the initial velocity and energy release rate threshold. Consequently, in cases where the theoretical agreement with the data is reasonable, the successive cracks show velocity curves that scale with each other.

Dark field illumination of material stained for neurosecretion

1975 ◽  
Vol 89 (1) ◽  
pp. 175-180 ◽  
Author(s):  
N.V. Swindale ◽  
P.R. Benjamin
Keyword(s):  
Dark Field ◽  
Dark Field Illumination
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