For any number of reasons you will end up shooting in Manual mode.
When this happens it is handy to have a way to set your exposure simply by being aware of the ambient light.
The first rule that has been around for nearly 100 years is the Sunny 16 rule.
We have included some other exposure guides for common situations you may face.
[hide][top]Other Exposure Settings
While we are at it, here are some other handy guides for setting exposures.
For obtaining a proper exposure of a full moon is to set the aperture at f/11 and shutter speed at one over the ISO setting (eg. 1/125 for ISO 100). For pictures of a half moon, use the same shutter speed at f/8. For a quarter moon, f/5.6.
Lenses and cameras never used to have anti-shake systems built into them.
As shutter speeds got slower, camera shake was likely to blur your image, and you had to know what you could safely get away with!
As a rule-of-thumb, the slowest shutter speed at which you could safely handhold a 35mm camera was usually considered to be one over the focal length of the lens.
So, if you're using a 50mm lens, you could generally shoot at 1/60 sec or faster. A 100mm lens needed at least 1/125 sec.
Not enough light to do that? Then you had to use flash, a tripod, or brace your camera (and yourself) against a solid object.
For cropped sensor cameras which are typically a 1.5 focal length multiplier you should factor that into your calculations.
So a 100mm on a 1.5 crop will need at least 1/150 shutter speed to avoid camera shake.
If your camera has Shake Reduction (Pentax & Sony) or your lenses have IS/VR (Canon or Nikon) then these features give you more latitude.
The classic advice is, "Expose for the highlights and let the shadows take care of themselves." This works with slide film and digital.
But with negative film, especially colour negative film, you're actually better off overexposing by one stop.
On digital camera's you have a histogram. Expose to the Right (ETTR) simply means exposing such that the histogram
shows as much as possible to the right (bright side) without clipping (the bit that is hard up to the right).
|A histogram for a normal good exposure
||A histogram showing an ETTR exposure
||A histogram showing clipping (blown highlights)
To stop action moving across the frame that's perpendicular to the lens axis,
you need shutter speeds two stops faster than action moving toward or away from you.
For action moving at a 45-degree angle to the lens axis, you can use a shutter speed one stop slower.
For example: If a person running toward you at moderate speed can be stopped at 1/125 sec,
you'll need a shutter speed of 1/500 sec to stop the subject moving across the frame,
and a shutter speed of 1/250 sec to stop him if moving obliquely with respect to the camera.
SAFETY FIRST: If you spent any time with a magnifying glass as a kid you've probably harnessed a little solar energy to burn stuff.
It doesn't take much of a magnifying glass to make things burn; so it stands to reason that pointing a camera or telescope, of ANY size, at the Sun is going to quickly and irreversibly burn things if you aren't careful.
And, unlike a magnifying glass, you may not get a little warming to first warn you.
To get a properly exposed sunset, meter the area directly above the sun (without including the sun).
If you want the scene to look like it's a half-hour later, stop down by one f-stop,
or set exposure compensation (if you have it available) to minus one.