What did photographers do for correct exposure before these computers with lenses that we now use for cameras? Lots of experience learned through lots of trial and error or external light meters among other things. Read Ansel Adams’ books for a view of how things were in the “good old days”.
Some of those old techniques may still come in handy today – certainly if you have your exposure mode set to manual. Let’s consider a very fundamental rule of thumb that applies as much today as in days of yore – the Sunny 16 Rule. Sunny 16 is a method for estimating correct exposure without a light meter. The rule simply states –
On a sunny day,
- Set the aperture to f/16
- Set the shutter speed to the reciprocal of the ISO (1/ISO sec.)
- And – that’s it!
- Any setting can be altered from the base rule via the light-stops relationshipbetween aperture, shutter speed & ISO
- For example, from a ISO 200 base setting of –
- f/16 , 1/200s, ISO 200 we could change to
- f/11, 1/400s, ISO 200, or
- f/16, 1/100s, ISO 100, or………
- Set your exposure mode to manual and try Sunny 16 on a sunny day.
- It’s not exact, but should get you close
- If you made your initial setting via Sunny 16 & then bracketed on either side you’d probably find a keeper
- As an alternative to auto-bracketing use our previous histogram & exposure compensation technique (my preferred approach)
- Another experiment – try this for a shot of the moon (as large as you can make it)
- The (near) success of Sunny 16 in this case relies on the fact that the moon is a body bathed in bright sunlight – thus justifying a try of Sunny 16.
- Again, auto-bracket and see what you get
- Compare this with spot metering the moon while using aperture priority. You can use a wide aperture since you’ll focus on the moon and DOF isn’t an issue. And – a tripod, of course.
- A final experiment – try this on a cloudy day.
- Don’t adjust anything but aperture
- What is the magic number for a high overcast cloudy day, for example?
- We know that it’s a wider aperture than f/16
- The Cloudy 11 Rule? Cloudy 8??? Depends on how cloudy “cloudy” is (or is it what the definition of “is” is, Bill?).
Here are some cloudy day experiment images –
Left to Right – f/16, f/11, f/8 (all at ISO 200, 1/200s)
This morning was a Cloudy 8 kind of day.
Another manual exposure tip – use your camera’s manual exposure display when setting aperture and shutter speed. The information and display will vary by camera make & model but will be something like this (from my D300 which provides the info in two places – control panel & viewfinder). My display said that the f/8 image above was still slightly underexposed (by 1/3 stop; close enough) –