Phal
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Flash not in Sync
HiI have a Nikon N80. When I use the built-in flash with Aperture Priority,
the pictures are underexposed. This though does not happen everytime. I am confused. Should I shoot in 'P' mode when I am using the built-in flash? thanks
11/10/2004 10:55:26 AM
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Jon Close
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What aperture are you setting in Av mode, and what ISO film? If you set too small an aperture, your subject may be beyond the useful range of the built-in flash. The guidenumber for the N80's built-in flash is 39 ft at ISO 100. The maximum useful distance is = squareroot(film ISO/100) x 39/aperture. So, for example, if you're using ISO 200 film and set f/16, the useful flash distance is only about 3-4 feet. squareroot(200/100) = 1.414.
1.414 x 39/16 = 3.45 ft.
11/10/2004 1:20:59 PM
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Phal
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Thanks Jon.
I was using ISO 100. I dont remember the Aperture setting. Now I have some more ques
1. Do I always need to do this calc mentally or use a larger aperture to be safe.
2. what diff would it make in 'P' mode.
3. Should I avoid the built-in flash
and use an external instead. thanks
11/11/2004 6:42:15 AM
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Jon Close
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You generally should keep the maximum range in mind when using the flash. P mode will probably tend to choose an aperture close to wide open, so with a f/3.5-5.6 zoom the maximum range would be about 7-12 ft. with ISO 100 and 2x that with ISO 400. If the budget allows, a higher powered accessory speedlight is always preferred over the built-in.
11/11/2004 7:28:05 AM
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