With the research on microscopic imaging, CCD camera by more and more researchers attention, some netizens face numerous brand models but do not know how to choose. Generally in the purchase of CCD focus on the number of CCD pixel resolution, except for the resolution , actually other performance index of CCD is more worthy of attention of consumers, such as chip size, pixel size.
1.CCD (camera) is the English Charge Coupled Device acronym, meaning the Charge Coupled Device. It is a kind of metal oxide semiconductor (MOS) technology based on the photosensitive element, covered with a lot of photosensitive element, each photosensitive element we called a pixel! CCD is one of the most important parts in the camera, it is up to the light is converted into an electrical signal role, similar to the human eye, so its performance will directly affect the camera performance. At present, CCD already has a wide spectral response range, detection limit, wide dynamic range, low dark current and low readout noise and signal integration, simultaneous signal detection and real-time monitoring capability.
2.Major determinants of CCD camera imaging quality: physical resolution, chip size, pixel size, signal-to-noise ratio, gray value.
The physical resolution: CCD camera's resolution. Pixel is the basic unit of the digital image, each pixel is a small point, and different color point (pixel) together into a moving picture, CCD often in pixels as classification according to the grade, the same chip size, the more pixels the higher the resolution. The chip size: digital cameras are 2/3 inch, 1/1.8 inch, 1/2.7 inch. CCD size is large, the photosensitive area is larger, the better the effect of imaging. The 4000000 pixel camera such as 2/3 inch 3000000 pixel camera effects are better than 1/1.8 inch (photosensitive area of which only the former 70%). If the increase at the same time the CCD pixel image quality to maintain existing, the total area must increase CCD based on at least a single pixel area is not reduced. More professional digital camera, CCD size is greater. At present, CCD processing larger
manufacturing more difficult and the more high cost .
Pixel: the basic unit of CCD photosensitive layer. The order of microns in diameter. CCD unit area pixels in an image more, the more detailed, the higher the resolution. CCD pixel size increase of course is a good thing, but too much will lead to a single pixel photosensitive area reduced ,produce insufficient exposure, and each pixel point is easy to produce interference optical signal, but the impact of image clarity.
The signal-to-noise ratio is normal light signals generated by the CCD camera with an abnormal signal(noise)ratio. Signal-to-noise ratio is high, indicating abnormal signal generating less, the image quality is more real, more clearly.
The gray value of the unit is Bit (a): computer image of the term, used to describe the generated image can contain the number of colors. "The depth is 8" means that the image contains only 28 or 256 colors. The higher the gray value, gray scale more camera can be resolved, color is more rich.
3，The preparation steps to buy camera
Step 1:clear to purchased CCD microscope camera and purposes.
Determine the purposes to buy CCD is very important, only by understanding their own needs, we can have a definite object in view to choosing to buy what they really need machine. Not the blind pursuit of high pixel resolution, for example for fluorescence black-and-white CCD, can meet the general in the about 1000000 pixels, pixel points less, photosensitive strong, is in line with the characteristics of weak fluorescence.
Step 2: CCD microscope camera psychological price
A decision can withstand the psychological price in accordance with the number of scientific research funds, such as the 10000 -50000. It can help us save a lot of time, can be in the choice of when more objective.
Step 3: not necessarily to buy from the microscope manufacturers
Everyone likes to buy microscope with CCD camera together, this is good, can guarantee the system, but sometimes it is not the way to save money, the general microscope manufacturers of CCD are OEM other home, that is not their production, or to buy the others. So that it is better to find a more cost-effective CCD, first of all to ensure the use of microscope and matching, and also save money, what is there against it?
Step 4: the trial is the kingly way
Just look at the data, we can only have a perceptual knowledge, only the actual to use machines to be rational. Then you can let manufacturers make a demonstrate , sometimes CCD camera 10000000 pixels are not necessarily higher than 5000000 make clear, so it is best to give it a try, the result is more at ease! JPLY recently launched the "free trial" activities, if interested can to take participate in . Activities web: http://www.spectrumsee.com/EN/Default.aspx
