GoingManual.com It's time to take control!    Home    Tutorials    Photography Forum  Photography Tutorial Introduction Part I – Gear The Camera  -  Focus  -  Resolution  -  MegaPixels Vs Print Size  -  Sharpening Semi auto settings  -  Aperture Priority (Av)  -  Shutter priority (Tv) Zoom and Focal Length  -  A Note About Sensor Size Other Camera Features  -  Viewfinders  -  Lens Hood  -  LCD screen  -  White Balance Extra Equipment  -  Tripod  -  Cable Release  -  Filter systems  -  Polarizer and ND filter  -  External Flash  -  Studio Lighting  -  Reflectors Part II – Capturing The Scene Your First Manual Photo  -  It's All About Exposure  -  The Light Meter  -  Exposure Explained  -  Controlling Exposure Creative Effects  -  Aperture and Depth Of Field  -  DOF Preview  -  Shutter speed Putting it all Together  -  ISO  -  Ap. & Shutter Relationship  -  Stop for a minute  -  So What?  -  The Bulb Setting Metering the Scene  -  18% of Everything Metering modes  -  Matrix  -  Average  -  Center weighted  -  Spot or semi-spot Taking Meter Readings  -  Expose for your subject  -  Sunsets and sunrises  -  Reflecting sun  -  Night Exposures  -  Moon  -  Green Foliage  -  Bright or White Scenes  -  Dark or Black Scenes Understanding Your Histogram  -  Flash Metering Composition Lead in The Viewer Eye  -  Point of Focus  -  Fill the frame  -  The Rule of Thirds  -  Moving Subjects  -  Print and frame Sizes Different Styles Learn by doing  -  Giving and Getting Critique  -  Portraits  -  Groups  -  Children  -  Shooting Outdoors  -  Silhouettes  -  Macro  -  Products  -  Landscapes  -  Sports and Action  -  Panning  -  Rear Sync Flash  -  Abstract  -  Long Exposures  -  Black and White A few Other Useful Things  -  Blown Out Skies  -  Neutral Density Filters  -  Polarizing Filters  -  Electronic noise You're Half Way There! Part III The Digital darkroom  -  Computer hardware  -  Card Reader  -  Printers  -  Mouse Post Processing  -  The Ethics of Altering  -  Choosing Your Program  -  Tutorials   Photoshop Tutorials   Photoshop Primer   Saving Your Image   Adding a Border   Using Levels   Using Curves   The S-Curve   Correcting White Balance   Improving Saturation   The Clone Tool   Correcting Lens Distortion   Blending Multiple Images   Black and White Conversion   Sepia Conversion   Reducing Noise   Cropping for Different Print Sizes   Sharpening   Working With RAW Files   The Gimp Tutorials   The Gimp Primer   Saving Your Image   Adding a Border   Using Levels   Using Curves   The S-Curve   Correcting White Balance   Improving Saturation   The Clone Tool   Correcting Lens Distortion   Blending Multiple Images   Black and White Conversion   Sepia Conversion   Reducing Noise   Cropping for Different Print Sizes   Sharpening   Working With RAW Files   << Stop For a Minute Metering the Scene >> The Bulb Setting A useful application of this knowledge is very long exposures. If your camera has a B or bulb setting you can keep you shutter open as long as you hold the shutter release down, you might need to use a cable release for this to avoid shaking the camera, and of course a tripod or steady surface. Unfortunately the light meter doesn't work on bulb. On my camera I can set the shutter to automatically close after 30 seconds. Beyond that I have to use the bulb setting to open and close it manually, based on my on timings. Imagine a low light scene where a high DOF is required for the desired creative effect, where everything is in focus from front to back. We already looked at how to achieve a high DOF, I need a small aperture. But when I try to set my shutter speed I need more than 30 seconds. So I can't get my light meter to show a correct exposure. If I set my shutter speed to it's maximum before the bulb, in my case 30 seconds, I can open up my aperture (and increase my ISO) until the light meter shows a correct exposure. Say, for example, the light meter says a correct exposure is 30s, f/8, ISO 1600 but I want the maximum DOF I can get at f/22. The light meter won't work above 30 seconds but I can take the data I have and work out my settings. Shutter speed F/# ISO 30s f/8 1600 60s f/11 1600 120s f/16 1600 240s f/22 1600 Decreasing ISO 480s f/22 800 960s f/22 400 1920s f/22 200 3840s f/22 100 All the values in this table result in the same exposure. If I can use my light meter to get a reading, I can use that information to change the set up to the creative settings I want. Each increase in f/# will halve the light so doubling the time compensates. Each reduction of ISO halves the sensors sensitivity to light, again doubling the time compensates. Unfortunately in digital photography both long exposure and high ISO cause noise. Film users can extend the shutter times without incurring a noise penalty. Tip: ISO, Aperture and shutter speed all work together to control how much light reaches the sensor. If you increase one you must decrease one or both, of the other two. So time for a headache tablet and a break. It's not easy to get this, so if you're not understanding it, give it another read. If you're still not clear don't stop, just have a go and post your experiments and questions in the forums at www.GoingManual.com. Post your images, good or bad, and tell the other forum users what you were trying to do. Together we can try to work out the problems. << Stop For a Minute Metering the Scene >>

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