scholarly journals Muti-Color Imaging of Clusters of Galaxies with Mosaic CCD Cameras

1998 ◽  
Vol 179 ◽  
pp. 287-290
Author(s):  
S. Okamura ◽  
M. Doi ◽  
N. Kashikawa ◽  
W. Kawasaki ◽  
Y. Komiyama ◽  
...  
Keyword(s):  
Ccd Camera ◽  
Photometric Data ◽  
Clusters Of Galaxies ◽  
Ccd Cameras ◽  
Color Imaging ◽  
Reasonable Amount ◽  
Multicolor Imaging ◽  
Photographic Photometry

At present, the photometric data for clusters at z ≲ 0.2 mainly come from photographic photometry. The lack of CCD data for such clusters is simply due to the fact that no CCD camera had been available until recently that covers the wide extension of clusters within a reasonable amount of observing time. We have developed a large mosaic CCD camera and conducted multicolor imaging observations of z ≲ 0.2 clusters using the 40-inch Swope telescope at Las Campanas Observatory.

Muti-Color Imaging of Clusters of Galaxies with Mosaic CCD Cameras

1997 ◽  
pp. 287-290
Author(s):  
S. Okamura ◽  
M. Doi ◽  
N. Kashikawa ◽  
W. Kawasaki ◽  
Y. Komiyama ◽  
...  
Keyword(s):  
Clusters Of Galaxies ◽  
Ccd Cameras ◽  
Color Imaging

Optical Identification of the ROSAT All-Sky Survey Sources in Two 2° × 2° Fields

1997 ◽  
Vol 159 ◽  
pp. 427-428
Author(s):  
Y. Zhao ◽  
J. Zhong ◽  
J. Wei ◽  
J. Hu ◽  
Q. Li
Keyword(s):  
Ccd Camera ◽  
Seyfert Galaxies ◽  
Astronomical Observatory ◽  
Active Galaxies ◽  
Clusters Of Galaxies ◽  
Late Type ◽  
Optical Identification ◽  
X Ray ◽  
Sky Survey

AbstractWe used the CCD camera and spectrograph of the 2.16-m telescope of Beijing Astronomical Observatory to identify the ROSAT All-Sky survey sources in two 2° Ü 2° fields. Of a total of 16 X-ray sources, we identified 13 of them as follows: two QSOs, two Seyfert galaxies, two active galaxies, two clusters of galaxies, and five late-type stars. Three X-ray sources remained unidentified.

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.

scholarly journals CCD Standard Fields

1993 ◽  
Vol 136 ◽  
pp. 73-78
Author(s):  
D.H.P. Jones
Keyword(s):  
Ccd Camera ◽  
Data Archive ◽  
Ccd Cameras ◽  
Isaac Newton ◽  
La Palma ◽  
Zero Points ◽  
Made In

AbstractThere are several standard fields for CCDs available in the literature. Some of these have been observed many times with the CCD cameras of the Isaac Newton Group of Telescopes on La Palma. These observations were made in order to establish the zero-points and colour equations for the U BV RI filters. Now that many observations are available in the data archive it is possible to combine them and search for inconsistencies in the published magnitudes and colours. This discussion will lead to standard fields of a higher quality. Furthermore astrometric plates have been taken of several of these fields which will be used to provide accurate positions as well as magnitudes and colours. These will provide the scale, orientation and distortion of any CCD camera.

scholarly journals A Photometric and Morphological Investigation of Very Remote Clusters

1983 ◽  
Vol 104 ◽  
pp. 223-225
Author(s):  
A. Kruszewski ◽  
R. M. West
Keyword(s):  
Ccd Camera ◽  
Clusters Of Galaxies ◽  
Morphological Investigation

About 500 remote, mainly compact clusters of galaxies have been identified on ESO (R) Schmidt plates; around 40 of these have been observed with the ESO CCD camera on the Danish 1.5-m telescope on La Silla. We describe the method of identifying the clusters and give some preliminary photometric results.

Compensating for the Phosphorescent Persistence in Intensified Cameras for Micro-PIV

2008 ◽  
Author(s):  
Adric Eckstein ◽  
Pavlos Vlachos
Keyword(s):  
Signal To Noise Ratio ◽  
Image Intensifier ◽  
Ccd Camera ◽  
Attractive Alternative ◽  
Cmos Camera ◽  
Signal To Noise ◽  
Ccd Cameras ◽  
Micro Piv ◽  
Noise Ratio ◽  
Cooled Ccd

Micro-PIV experiments rely upon the use of a microscope to achieve the higher spatial resolution. However, several optical limitations are introduced at these scales [1–3]. In addition, due to the low illumination levels, micro-PIV experiments require the use of either a cooled CCD camera or an image intensifier to provide increased signal-to-noise ratio. Although CCD cameras offer superior sensitivity and signal to noise ratio, intensified CMOS cameras offer an attractive alternative for performing high frequency measurements. However, intensified cameras are known to introduce artifacts such as added background noise. This study examines these issues and the feasibility of employing such technologies for microPIV through the use of the IDT-X5 intensified CMOS camera, capable of 500 Hz at a resolution of 2352×1728 pixels, with pulse separations as low as 2μs.

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.

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