Light Microscopy Flashcards
What is refraction?
The change in direction of light when passing from one medium to another
What type of lens allows magnification?
Convex
What are parafocal objectives?
If focus image in one magnification then it will remain close to the focal plane at the next magnification
What is a refractive index?
How much a material refracts the light
What is light scatter?
Where light is refracted and radiates out from the sample and can reduce the amount of light collected by the objective
What causes light scatter?
The difference between the refractive index of air and glass
Why are air objectives not suitable for high magnification microscopy?
Light scatter is okay when objective is large at low magnifications but when objective is small at high magnifications much of the light isn’t collected so low quality
Why does oil immersion microscopy allow higher magnifications?
Gives a continuous physical contact between slide and objective and oil has the same refractive index as glass preventing light scatter
- increases resolution
Define resolution
The minimum distance at which two points can be distinguished within a defined space
Define exposure time
The length of time light is collected to produce an image
What is light formed?
Protons
What controls the intensity of an image?
The amount of a time the sensor chip is exposed to the inch,bing light which is converted into a digital image
What happens when exposure time is too long?
Areas become saturated and appear white
What happens when exposure time is too short?
Image lacks detail
What is gain?
The digital amplification of the data collected at a particular exposure time
