1.1.5—Resolution and magnification
- Syllabus
- 9700–2028–2029
- Objective
- 1.1.5
- Level
- AS
Resolution is the detail limit; magnification is only enlargement
Resolution is the smallest separation at which two points can still be distinguished as separate. Magnification makes an image larger; resolution determines whether that enlargement reveals new detail.
| Feature | Magnification | Resolution |
|---|---|---|
| Meaning | Image size ÷ actual size | Smallest separation that can still be distinguished |
| What increasing it does | Enlarges the image | Improves the ability to separate close points |
| Limiting idea | Can enlarge existing blur | Depends on the instrument and wavelength; enlargement alone cannot recover lost detail |
- Light microscope: visible light has a longer wavelength, so closely spaced structures have a coarser resolution limit.
- Electron microscope: electrons have a much shorter effective wavelength, so finer ultrastructure can be resolved.
Cristae in a mitochondrion may be present in an image but appear merged under a light microscope. Higher magnification alone would enlarge the blur; higher resolution is what separates the membranes.
A larger image is not automatically a more informative image. State magnification and resolution separately when explaining why an electron microscope is needed.
ConceptA-Level CAIE Biology AS