Enhancement of Differential Interference Contrast Images of Live Cells Obtained With Digital Cameras

1999 ◽  
Vol 5 (S2) ◽  
pp. 1112-1113
Author(s):  
M.V. Parthasarathy
Keyword(s):  
High Resolution ◽  
Contrast Enhancement ◽  
Dynamic Range ◽  
Ccd Camera ◽  
Video Camera ◽  
Live Cells ◽  
Photographic Emulsion ◽  
Digital Cameras ◽  
Structural Detail ◽  
Ccd Cameras

The usefulness of Differential Contrast Interference (DIC) light microscopy for observing fine details within transparent specimens is well known. However, when viewed by the eye or by recording with photographic emulsion, fine structural detail at the limit of resolution is often not visible because of lack of contrast. To overcome this problem, electronic contrast enhancement capabilities of video cameras have been used to enhance structural details that would otherwise be invisible. The technique, commonly referred to as VE-DIC (Video Enhanced DIC), uses first analog contrast enhancement of the image with a video camera followed by a real-time digital image processor to further enhance the image with. We are exploring the feasibility of achieving fine structural detail of live cells by directly acquiring digital images of them with a high resolution CCD camera.High resolution cooled slow-scan 12-bit CCD cameras are well suited for DIC microscopy because of their greater dynamic range than video CCD cameras that are normally 8-bits or lower.

Slow-scan CCD cameras and low-dose High-Resolution Electron Microscopy: Direct and quantitative

1994 ◽  
Vol 52 ◽  
pp. 412-413
Author(s):  
M. Pan
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Damage ◽  
Low Dose ◽  
Dynamic Range ◽  
High Resolution Electron Microscopy ◽  
Operating Conditions ◽  
Digital Data ◽  
Ccd Cameras ◽  
Resolution Electron

It has been known for many years that materials such as zeolites, polymers, and biological specimens have crystalline structures that are vulnerable to electron beam irradiation. This radiation damage severely restrains the use of high resolution electron microscopy (HREM). As a result, structural characterization of these materials using HREM techniques becomes difficult and challenging. The emergence of slow-scan CCD cameras in recent years has made it possible to record high resolution (∽2Å) structural images with low beam intensity before any apparent structural damage occurs. Among the many ideal properties of slow-scan CCD cameras, the low readout noise and digital recording allow for low-dose HREM to be carried out in an efficient and quantitative way. For example, the image quality (or resolution) can be readily evaluated on-line at the microscope and this information can then be used to optimize the operating conditions, thus ensuring that high quality images are recorded. Since slow-scan CCD cameras output (undistorted) digital data within the large dynamic range (103-104), they are ideal for quantitative electron diffraction and microscopy.

The Use of Phase and Amplitude Information of Reconstructed Exit Waves

1997 ◽  
Vol 3 (S2) ◽  
pp. 1029-1030
Author(s):  
H.W. Zandbergen
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
High Resolution ◽  
Field Emission ◽  
Software Package ◽  
Dynamic Range ◽  
Ccd Camera ◽  
Phase Object ◽  
High Resolution Images

Exit waves can be reconstructed from through focus series of HREM images or by off-axis holography [1]. We have applied the through focus method to reconstruct exit waves, using algorithms developed by Van Dyck and Coene [2]. Electron microscopy was performed with a Philips CM30ST electron microscope with a field emission gun operated at 300 kV. The high resolution images were recorded using a Tietz software package and a 1024x1024 pixel Photometrix CCD camera having a dynamic range of 12 bits. The reconstructions were done using 15-20 images with focus increments of 5.2 nm. The resulting exit waves were corrected posteriorly for the three fold astigmatism.The exit wave is complex; consequently it contains phase and amplitude. Since in the very thin regions the specimen acts as a thin phase object, such a thin area will show little contrast, an example of which is shown in Figure 1.

Design of Calibration System for a Great Quantity of High Precision Scientific Grade CCD Cameras

2013 ◽  
Vol 331 ◽  
pp. 326-330
Author(s):  
Jia Hai Tan ◽  
Peng Yu Li ◽  
You Shan Qu ◽  
Ya Meng Han ◽  
Ya Li Yu ◽  
...  
Keyword(s):  
Camera Calibration ◽  
High Precision ◽  
High Energy Physics ◽  
Dynamic Range ◽  
Ccd Camera ◽  
High Energy ◽  
Integrating Sphere ◽  
Calibration System ◽  
Ccd Cameras ◽  
System A

For the calibration of a great quantity of scientific grade CCD cameras in the high energy physics system, a scientific grade CCD camera calibration system with high precision and efficiency is designed. The designed camera calibration system consists of a 1053nm nanosecond solid-state laser, a knife, a double-integrating sphere, a laser power meter, a signal generator, a computer with its data processing software. Key technical parameters of scientific grade CCD under the condition of 1053nm optical pulses that are the modulation, contrast, defects, optical dynamic range, non-linear response can be calibrated by the designed calibration system. A double-integrating sphere with high uniformity and stability is designed as a uniform light source, which improves the calibrating performance and accuracy. Experimental results show the system designed in this paper can calibrate the large number of scientific grade CCD cameras quickly and efficiently.

Research on performances of back-illuminated scientific CMOS for astronomical observations

2021 ◽  
Vol 21 (10) ◽  
pp. 268
Author(s):  
Peng Qiu ◽  
Yong Zhao ◽  
Jie Zheng ◽  
Jian-Feng Wang ◽  
Xiao-Jun Jiang
Keyword(s):  
Dynamic Range ◽  
Open Cluster ◽  
Field Tests ◽  
Ccd Camera ◽  
Good Choice ◽  
Short Exposure ◽  
High Temporal Resolution ◽  
Ccd Cameras ◽  
Astronomical Observations ◽  
Back Illuminated

Abstract To evaluate performances of a back-illuminated scientific CMOS (sCMOS) camera for astronomical observations, comparison tests between Andor Marana sCMOS and Andor iKon-L 936 CCD cameras were conducted in a laboratory and on a telescope. The laboratory tests showed that the readout noise of the sCMOS camera is about half lower, the dark current is about 17 times higher, the dynamic range is lower in the 12-bit setting and higher in the 16-bit setting, and the linearity and bias stability are comparable relative to those of the CCD camera. In field tests, we observed the open cluster M67 with the sCMOS and CCD cameras on a 60 cm telescope. Unlike the CCD camera, the sCMOS camera has a dual-amplifier architecture. Since a 16-bit image of the sCMOS camera is composed of two 12-bit images sampled with 12-bit high gain and low gain amplifiers simultaneously, it is not real 16-bit output data. The evaluation tests indicated that the dual-amplifier architecture of the sCMOS camera leads to a decline of photometric stability by about six times around specific pixel counts. For photometry of bright objects with similar magnitudes that require high frame rates, the sCMOS camera under 12-bit setting is a good choice. Therefore, the sCMOS camera is fitted with survey observations of variable objects requiring short exposure times, mostly less than 1 s, and high frame rates. It also satisfies the requirements for an offset guiding instrument owing to its high sensitivity, high temporal resolution and high stability.

Image-coupling methods in CCD cameras for Electron Microscopy

1994 ◽  
Vol 52 ◽  
pp. 406-407
Author(s):  
P. E. Mooney ◽  
O. L. Krivanek
Keyword(s):  
Electron Microscopy ◽  
Dynamic Range ◽  
Ccd Camera ◽  
High Sensitivity ◽  
Geometric Distortion ◽  
List Type ◽  
Ccd Cameras ◽  
Charge Coupled Device ◽  
Indirect Coupling ◽  
Coupling Methods

It is well established that the charge-coupled device (CCD) is the detector of choice in imaging applications requiring sensitivity, dynamic range, linearity and low geometric distortion. It has also been shown that in the electron microscope, indirect coupling of the image by a scintillator and transfer optic is required to prevent damage to the CCD and to allow for sufficient dynamic range. The question then follows how best to design the coupling to achieve the image quality required for digital imaging in electron microscopy.We have characterized slow-scan CCD cameras with three representative optical couplings (Figure 1):1:1 fiber-optically coupled camera with a large-pixel CCD (TK1024) and both single-crystal and powder scintillators for 100-400 kV applications requiring good sensitivity,1:1 tandem lens-coupled camera with a large-pixel CCD (TK1024) and a powder scintillator mounted on an ultra-thin Al foil for high voltage applications, and3:1 reduction macro lens-coupled camera with a fast, small-pixel CCD (Kodak MegaPlus) and thin scintillator mounted on a glass prism for applications requiring fast read-out, but not high sensitivity.In this abstract we compare the three coupling methods to each other, and also to a TV-rate fiber-optically coupled CCD camera.

A flexible, computer-controlled video microscope capable of quantitative spatial, temporal, and spectral measurements.

1981 ◽  
Vol 27 (9) ◽  
pp. 1558-1568 ◽  
Author(s):  
E S Rich ◽  
J E Wampler
Keyword(s):  
High Resolution ◽  
Kinetic Resolution ◽  
Dynamic Range ◽  
Image Intensifier ◽  
Video Camera ◽  
Exciting Light ◽  
Low Light ◽  
Camera System ◽  
Video Microscope ◽  
Computer Controlled

Abstract A video microscope system has been constructed and tested that incorporates computer-controlled video cameras for high-resolution and low-light microscopy. The low-light camera system involves a dual microchannel plate-image intensifier capable of photon gain as high as 500 000 and a gated silicone-intensified target vidicon to achieve usable photon sensitivity with a noise equivalent signal of only 2 photons (500 nm) per pixel per second. We have compared the limitations and capabilities of this camera system with those of a high-resolution video camera and conventional photomicroscopy. Uses of the low-light camera coupled to a computer system include image acquisition of weak-light images from self-luminous specimens, fluorescence microscopy with weak exciting light, kinetic resolution of calcium-mediated events as monitored by the calcium-sensitive bioluminescence of aequorin, and spatially resolved spectroscopic measurements. Flexible use of this system in these various applications is possible because it allows operation with illumination intensities over a dynamic range of 100 000:1.

High Dynamic Range Electron Imaging: The New Standard

2014 ◽  
Vol 20 (5) ◽  
pp. 1601-1604 ◽  
Author(s):  
Keith Evans ◽  
Richard Beanland
Keyword(s):  
Dynamic Range ◽  
High Dynamic Range ◽  
Digital Cameras ◽  
Ccd Cameras ◽  
Transmission Electron ◽  
High Dynamic ◽  
Electron Microscopes ◽  
Diffraction Patterns ◽  
Electron Imaging ◽  
Imaging Plates

AbstractTransmission electron microscopes regularly produce data which has a dynamic range that exceeds the capabilities of the recording media used, particularly in diffraction patterns. Hardware solutions such as readable phosphor imaging plates have existed since the 1990s, but in recent years the advent of robust CCD digital cameras capable of capturing high intensities in a transmission electron microscope has made image acquisition fast and straightforward. However, all CCD cameras have a saturation limit, making imaging of low intensities difficult when an image is dominated by strong features. Here we present a simple and effective tool to overcome this limitation through acquisition of multiple images and software processing to produce high dynamic range electron images.

On-line alignment and astigmatism correction using a TV and personal computer

1993 ◽  
Vol 51 ◽  
pp. 202-203
Author(s):  
F. Hosokawa ◽  
Y. Kondo ◽  
T. Honda ◽  
Y. Ishida ◽  
M. Kersker
Keyword(s):  
High Resolution ◽  
Personal Computer ◽  
Block Diagram ◽  
Incident Beam ◽  
Ccd Camera ◽  
Alignment Procedure ◽  
Astigmatism Correction ◽  
Transmission Electron ◽  
Alignment System ◽  
On Line

High-resolution transmission electron microscopy must attain utmost accuracy in the alignment of incident beam direction and in astigmatism correction, and that, in the shortest possible time. As a method to eliminate this troublesome work, an automatic alignment system using the Slow-Scan CCD camera has been introduced recently. In this method, diffractograms of amorphous images are calculated and analyzed to detect misalignment and astigmatism automatically. In the present study, we also examined diffractogram analysis using a personal computer and digitized TV images, and found that TV images provided enough quality for the on-line alignment procedure of high-resolution work in TEM. Fig. 1 shows a block diagram of our system. The averaged image is digitized by a TV board and is transported to a computer memory, then a diffractogram is calculated using an FFT board, and the feedback parameters which are determined by diffractogram analysis are sent to the microscope(JEM- 2010) through the RS232C interface. The on-line correction system has the following three modes.

Multi-mode light microscopy of microtubule assembly dynamics and chromosome movement in vivo and In vitro

1996 ◽  
Vol 54 ◽  
pp. 730-731
Author(s):  
E. D. Salmon ◽  
J. C. Waters ◽  
C. Waterman-Storer
Keyword(s):  
Imaging System ◽  
Ccd Camera ◽  
Transmitted Light ◽  
Microtubule Assembly ◽  
Live Cells ◽  
Optical Efficiency ◽  
Multiple Band ◽  
Multi Mode

We have developed a multi-mode digital imaging system which acquires images with a cooled CCD camera (Figure 1). A multiple band pass dichromatic mirror and robotically controlled filter wheels provide wavelength selection for epi-fluorescence. Shutters select illumination either by epi-fluorescence or by transmitted light for phase contrast or DIC. Many of our experiments involve investigations of spindle assembly dynamics and chromosome movements in live cells or unfixed reconstituted preparations in vitro in which photodamage and phototoxicity are major concerns. As a consequence, a major factor in the design was optical efficiency: achieving the highest image quality with the least number of illumination photons. This principle applies to both epi-fluorescence and transmitted light imaging modes. In living cells and extracts, microtubules are visualized using X-rhodamine labeled tubulin. Photoactivation of C2CF-fluorescein labeled tubulin is used to locally mark microtubules in studies of microtubule dynamics and translocation. Chromosomes are labeled with DAPI or Hoechst DNA intercalating dyes.

Sign in / Sign up

Export Citation Format

Share Document