Photography Basics: Achieving Correct Exposure
Understanding Exposure
- Definition: Exposure is the process of taking a picture that appears as desired.
- Correct Exposure: An image that looks the way you intend it to, not necessarily matching what your eyes see.
- Example Scenario: Setting an exposure based on what the eyes perceive.
Camera Modes
- Scene Intelligent Auto: Automatically judges exposure.
- Manual Mode (M): Allows full control over settings.
- Useful for learning camera settings and achieving desired exposure.
Key Settings for Exposure
- Shutter Speed
- Definition: Duration the shutter remains open.
- Current Setting Example: 1/500th of a second.
- Impact: Controls motion blur; slower speeds can cause blur if the subject or camera moves.
- Aperture
- Definition: Size of the lens opening, expressed in fractions (f-stops).
- Range: Typically from f/1.2 to f/36.
- Impact: Larger apertures (smaller f-numbers) allow more light and create shallow depth of field.
- ISO
- Definition: Sensor sensitivity to light.
- Larger numbers increase sensitivity.
- Doubling ISO doubles sensitivity (ISO 200 is twice as sensitive as ISO 100).
Practical Examples
- Using Live View: Shows expected exposure with current settings.
- Adjusting Settings:
- Shutter Speed: Adjust for motion blur - lower speeds for still scenes, higher for motion.
- Aperture: Affects depth of field; wider openings for blurred backgrounds, narrow for sharpness.
- ISO: Adjust to maintain exposure with desired shutter and aperture.
- Example Settings: 1 second, f/22, ISO 100 for a still life.
- Benefits: Crisp images with controlled exposure.
- Adjusting for Handheld or Moving Subjects:
- Shutter speed faster than focal length rule (e.g., 35mm lens needs > 1/35th second).
- IS (Image Stabilization) can lower necessary shutter speed.
- Moving subjects: Typically need shutter speeds of 1/125th seconds or faster.
Tips for Exposure Control
- Start with desired aperture based on scene needs.
- Adjust shutter speed and then ISO to achieve desired exposure.
- AV Mode: Set aperture and let the camera adjust shutter speed.
- Avoid Auto ISO: Allows for too much camera control, which may lead to incorrect exposures.
- ISO Considerations: Entry-level DSLRs should avoid going above ISO 1600 to prevent noise.
Conclusion
- Cameras, despite their advanced features, rely on user input for optimal exposure settings.
- Exposure adjustment is a balance between avoiding blur and obtaining desired depth of field and brightness.
- Upcoming content will cover more detailed scenarios and "recipes" for common photography situations.
Note: For further clarification or questions, engage with the video creator through comments or social media.