f stop & shutter speed & how they relate

1. f stop & shutter speed&how they relate

2. F-Stop & Shutter speed • They control the amount of light the lens will supply to the digital imaging sensor or film in the camera body • F stop is the amount of light the lens will let in while the shutter is open • Shutter speed is the amount of time the shutter is open

3. F-stop • Common f-stops range from f/1.8 to f/22 • The smaller the number the larger the opening in the lens. More light enters • The larger the number the smaller the opening in the lens. Less light enters

4. Shutter Speed • Shutter speed is measured in fractions of a second to several seconds or even minutes • Most common shutter speeds are 1/15th of a second to 1/1000th of a second • There are other shutter speeds outside of this range and are used for special circumstances

5. Depth of Field • Depth of field is the area from near to far that is in focus • Smaller f-stop numbers (larger aperture opening) will have a smaller depth of field • Larger f-stop numbers (smaller aperture opening) will have a larger depth of field

6. Depth of Field • For portrait photography a smaller depth of field is usually desired so use a smaller f-stop number (larger aperture opening) for a shallow depth of field. Usually in the range of f/2.8 – f/5.6 • For landscape photography a larger depth of field is usually desired so use a larger f-stop number (smaller aperture opening) for a larger depth of field. Usually in the range of f/11 – f/16

7. Depth of Field f/2.8 f/22

8. Depth of Field f/22 f/4

9. Shutter Speed • Shutter speed will control blur. Fast moving subjects require a higher shutter speed if sharpness is desired • A portrait usually does not need a high shutter speed. A shallow depth of field may be desired • But remember: small f-stop = more light • So: • The amount of light available will dictate what shutter speed can be used for proper exposure!

10. F-Stop & Shutter Speed • The amount of available light will dictate what shutter speed / f-stop combinations can be used • Which combination you use will depend on what effect you are trying to achieve • Fast moving car? Landscape? High noon in summer or late evening in winter? • Shallow depth of field or large depth of field?

11. Stops • F-stop & shutter speed are very inter-related • Both can be measured in stops • The stop is a basic unit of light in photography • Stops can be controlled by f-stop, shutter speed & iso

12. Standard f-stops • Standard f-stops are: • 1.4 – 2 – 2.8 – 4 – 5.6 – 8 – 11 – 22 – 32 – • There are others outside of this range but most are outside of consumer grade optics • Standard shutter speeds are: • 1/2 – 1/4 – 1/8 – 1/15 – 1/30 – 1/60 – 1/125 – 1/250 – 1/500 – 1/1000

13. Stops • Minus one stop halves the amount of light and plus one stop doubles the amount of light • Going from 1/60th to 1/30th of a second will double the amount of light • Going from 1/30th to 1/60th of a second will halve the amount of light • By moving f-stop one stop the shutter speed will move one stop in the opposite direction for proper exposure. The same applies to shutter speed vs f-stop. Moving one will move the other in the opposite direction.

14. Exposure Value • Exposure value or E.V. are specific combinations of f/stop & Shutter Speed. • f/8 at 1/125 sec can be expressed at EV 13 • f/8 at 1/250 can be expressed as EV 14 or one stop slower.

15. Iso • Iso is the sensitivity of the film or digital sensor to light • The higher the iso number the more sensitive the digital sensor or film is to light • Standard iso settings are: • 50 – 100 – 200 – 400 – 800 – 1600 - 3200

16. Iso • Increasing the iso one step doubles the amount of light (one stop) • Decreasing the iso one step halves the amount of light (one stop) • Caution should be taken when using higher iso settings as they can introduce noise especially in the shadow areas

17. Aperture • Aperture settings are described in f-stops • Standard f-stops are: • 1.4 – 2 – 2.8 – 4 – 5.6 – 8 – 11 – 16 – 22 – 32 • Going from f/4 to f/5.6 halves the amount of light (one stop) • Going from f/5.6 to f/4 double the amount of light (one stop)

18. Exposure • A scene can have many different f/stop & shutter speed combinations • F/4 at 1/250 is the same exposure as f/5.6 at 1/125 or f/8 at 1/60 or f/11 at 1/30 • Which one you use will depend on what you are trying to achieve in the image

19. Exposure • Freeze action or blur? • Large or shallow depth of field? • It is very useful to understand the inter-relationship of f-stop and shutter speed • Controlling aperture for depth of field and shutter speed for freezing or blurring action is one of the basic tenants of creative photography

20. Dynamic Range • Dynamic range is the range between the brightest area in a scene and the darkest • The human eye can see about 18 stops of light • Most digital cameras can detect 6 – 9 stops of light depending of optics, use of camera raw or hdr

21. Exposure • A forest scene with the sun shining through the tree tops may have more than dynamic range (stops of light) than your camera can capture • Matrix or evaluative metering combines the exposure for the highlights and the shadows to create an average. • It will have either blown out highlights or plugged up shadows

22. Exposure • This is where knowledge of stops in photography comes in handy • Shooting multiple frames at different exposure compensation levels (-1 stop and +1 stop and one at the recommended exposure) will help

23. Conclusion • F-stop and shutter speed are inter-related • Learn this inter-relation ship to really bump up your creative photography skills • Use aperture priority (av) or shutter priority (tv) on your camera, or even manual mode!