Proper Exposure

 

We have found that most digital cameras require "Exposure Compensation" when using studio lighting. Exposure Compensation provides the ability to influence the auto exposure control of the camera and allow you to correctly expose an object especially against a white background.

You will need to experiment with your camera until you get satisfactory results and them leave the camera set to the necessary exposure compensation setting. 

 

Exposure can be adjusted several ways including exposure value (EV), ISO setting and metering.

• Exposure Value (+/-EV) is the camera's way to offset exposure by adjusting the shutter speed and aperture setting.  You can also manually control shutter speed and aperture for the desired exposure.  Use the table below to get a general idea how EV changes your camera's shutter speed and aperture.

• Adjusting the ISO setting can also be used to adjust the exposure. ISO is a setting for light sensitivity.  ISO 100 is considered the "normal" setting for most cameras, although some go as low as ISO 50.  Higher sensitivity levels work well in low light conditions and increase exposure but image quality can become grainy - something to look out for.  Sensitivity levels can be increased to 200, 400, 800, or even 3,200 on high-end digital SLRs.

• Meter settings change how the camera uses the scene to provide an 18% grayscale exposure.  In other words, the camera's metering system is calibrated to a certain light value in order to guarantee constant exposure settings: 18% gray is commonly used in digital cameras because a typical scene reflects about the same amount of light as this gray value.  For comparison all these colors shown here reflect light in average about 18% gray: Usually this assumption works well but if you expose a scene with a majority of bright colors/grays without compensation in spot or center-weighted mode the camera will darken the photo to an 18% grayscale average - the result is under-exposure.  Most cameras are blind in regard to colors.

Manual Exposure Control

Manual control of exposure provides the ability to manage the aperture of the lens, which is very important for maximizing "depth-of-field". Small apertures (larger numbers like f-8 of f-11) are the most desirable settings to maintain sharp focus over an entire 3 dimensional object. Setting the camera to manual exposure control or "aperture priority" will allow for the selection of a small aperture.  When using "aperture priority" the shutter speed will be selected by the camera and in manual mode by the photographer. In many cases, with small apertures, the shutter speed will be slow and a tripod is essential.