How many times bigger the image of a specimen observed is in comparison to the actual (real-life) size of the specimen
Magnification Formula
Magnification (M) = Image/Imaging Size (I) / Actual Size of Specimen (A)
Units for measuring cell size
Micrometres (μm) or nanometres (nm)
Converting units
Multiply or divide by 1000 depending if the units are increasing or decreasing
Magnification does not have units
Eyepiece lens
Often has a magnification of x10
Objective lens
Series of (usually 3) lenses, each with a different magnification
Calculating total magnification
Eyepiece lens magnification x Objective lens magnification = Total magnification
Resolution
The ability to distinguish between two separate points
If two separate points cannot be resolved, they will be observed as one point
Resolution of light microscope
Limited by the wavelength of light
Electron microscopes have a much higher resolution and magnification than a light microscope as electrons have a much smaller wavelength than visible light
The concept of resolution is why the phospholipid bilayer structure of the cell membrane cannot be observed under a light microscope
The maximum resolution of a light microscope is 200nm (half the smallest wavelength of visible light, 400nm)
Any points that are separated by a distance less than 200nm (such as the 10nm phospholipid bilayer) cannot be resolved by a light microscope and therefore will not be distinguishable as "separate"
