Micro-photography (6) pharmaceuical R&D
Micro-photography (6)- pharmaceuical R&D
4. Exposure to determine
pharmaceutical Exposure is the key to a microscopic photography.
overexposed, so that the film density of large, dark is unclear, the loss of film grain detail, contrast is too small.
underexposed, the entire film density is very small, more transparent, although the maximum density part of the shadow pattern distinct, but the minimum density and fog density, without any shadow patterns, the lack of normal contrast. Type of film, simply can not emit a qualified photo printing.
pharmaceutical outsourcing Exposure of the most important issue is to determine the exposure time to determine the shutter speed.
clinical trial micro-vision photography, brightness is extremely volatile, exposure time, a wide range of variation, an accurate assessment of exposure time than regular outdoor photography much more difficult.
commonly used estimate of image brightness to determine the exposure time approaches, often due to the human eye to light intensity there will be no significant changes in science and quantitative analysis, which results in an error.
(1) factors affecting exposure
research Organization Consider the factors affecting exposure focus is to analyze as they are photographic or weakened. Brightness is to enhance the amount of time to reduce exposure.
High-voltage lighting, power, big light bulb, light, high strength, high color temperature, so that photographic film fast exposure time should be brief.
â’¡ film’s sensitivity to light sensitive film with high sensitivity, exposure time can be shorter. Film over the validity, or poor storage conditions, film sensitivity will be reduced when used, where appropriate, to increase exposure time.
numerical aperture objective lens and eyepiece magnification of the objective lens of numerical aperture large amount of light into the many large image brightness, exposure time should be short; eyepiece magnification large field of vision is relatively increased, the corresponding decrease image brightness, exposure longer.
â’£ the color filter filters light illumination intensity weakened. In photography must compensate to achieve the correct exposure.
Sintong Chemical Industrial Co., Ltd specimens of different thickness and color of samples changes in affect and absorption of light through. In addition, in the same samples, the amount of light the various parts of different degrees, thus also affect the exposure time.