Aaron Gold

The purpose of our Absolute beginner’s guide to film photography series is to help demystify the joys of shooting analog. And while we try not to dabble too much in specifics, there is one (sort-of) hard-and-fast analog-era rule we think every film (and digital) shooter should know: the ‘Sunny 16’ rule.

What is Sunny 16 and why is it important for film photography?

Sunny 16 is an easy way to set your camera’s exposure if you don’t have a working light meter or you suspect your camera’s light meter might be reading the scene improperly. The light meters in film cameras are generally much less sophisticated than those in today’s digital cameras, and they are easier to fool. The Sunny 16 rule provides a quick reality check on your meter readings, as well as a starting point to set exposure without the help of a meter.

How the Sunny 16 rule works

It’s simple: Sunny 16 says that on a sunny day, you should set your aperture to F16 and your shutter speed to the reciprocal of your film speed, or as close to it as you can get. So if you’re shooting 100 ASA film, set F16 and 1/90 or 1/125 sec. Running 400 speed film? Try F16 and 1/500 sec. Your exposure may not be perfect, but it will be close enough to get a usable shot.

The Sunny 16 rule gives us a quick reality check on our meter readings, as well as a starting point to set exposure without the help of our meter

What if the sun isn’t out? If it’s a little cloudy, use F11; overcast, use F8; thunderclouds, F5.6; sunset, try F4. For very bright scenes (like snow), go the opposite way and use F22. Can’t remember all that? Don’t worry, you can buy stickers and t-shirts to remind you.

If you understand the basics of exposure, you can find comparable exposures that will work. Let’s say it’s a sunny day and you’re shooting 100 speed film. The Sunny 16 Rule tells you to shoot at F16 at 1/125 sec. But what if you want shallower depth of field than F16 will provide? No problem – you can open up your lens by three stops to F5.6, and compensate with a three-stop-quicker shutter speed of 1/1000 sec.

Shooting film on a sunny day? According to the Sunny 16 rule, simply set your aperture to F16, your shutter speed to the reciprocal of your film speed (so if you’re shooting ISO 100 film, ~1/100 sec), and your exposure should be close-enough to spot on; amazing!

I have a meter, do I need Sunny 16?

The whole purpose of having a meter is so you can get a more precise exposure, but the meters in older film cameras are relatively easy to fool. Meters are calibrated for what is known as middle gray, and for most scenes, which have a mixture of light and dark areas, that’s close enough. But if you are taking a photograph of something unusually light or dark, like a snowy landscape or someone wearing dark clothing, your meter may not give the correct exposure information.

If you are taking a photograph of something unusually light or dark, like a snowy landscape or a dark building, your camera’s meter may not give the correct exposure information

Here, Sunny 16 can act as a check for metering errors. Let’s say it’s a nice sunny day, and you’re shooting a jet-black car on ISO 200 film. You set your shutter sped to 1/250, and your meter tells you to set F8. The meter ‘sees’ that dark car and interprets it as middle gray, so it’ll recommend a wider aperture that will overexpose your photo. The meter’s recommendation is two stops off of what Sunny 16 tells you, and that’s a good indicator that your meter is wrong.

Why are film camera meters so easy to fool?

Shooting on an overcast day? Sunny 16 has got your back, simply open up your camera’s aperture up to F8 (and be there!).

Today, most digital cameras use sophisticated multi-segment meters that break your scene up into small parts and examine each one. Some cameras have a built-in database of sample exposures that can help them determine the contents of your scene and meter accordingly. Mirrorless cameras measure exposure from the exact same imaging sensor that captures the picture (and you can preview exposure precisely in the viewfinder).

Most film cameras from the 1960s, 70s and 80s have a center-weighted meter – they average the whole scene but give more importance to what’s in the middle

Film camera meters are nowhere near that smart. Some late-model film cameras have multi-zone matrix meters, but (aside from a handful of flagship pro SLRs) they tend to have relatively few segments. Most film cameras from the 1960s, 70s and 80s have a center-weighted meter. These meters average the whole scene and give more importance (‘weight’) to what’s in the middle, since that’s how most people frame their subjects. Some center-weighted meters give less weight to the upper section of the photo, which is where the sky generally is. Just turning the camera sideways can be enough to throw off the meter. Some older cameras have a spot meter, which only measures what’s in the middle of the frame. Framing with your subject off center is enough to give an incorrect measurement.

How do you know how your camera meters? Your camera’s manual should have an illustration showing the meter pattern. More sophisticated film cameras will let you switch between matrix, center-weighted and spot modes, but they can still be fooled.

What about a snowy day? According to Sunny 16, stopping down to F22 should get you fairly close to an accurate exposure.

What do I listen to: the meter or the Sunny 16 rule?

The Sunny 16 rule is pretty accurate, to the point that some very simple cameras display a sun and clouds rather than F-stop numbers. If your camera is within a stop or so of the Sunny 16 rule, the exposure will generally be close; when in doubt, underexpose a bit.

If your camera is within a stop or so of the Sunny 16 rule, the exposure will generally be close

If your meter is way off from Sunny 16, you might want to hedge your bets by shooting three pictures – one taken at the meter’s indicated exposure, one using the Sunny 16 rule, and one right in the middle. Be sure to make a note of your exposures and then check the finished result to see which was the most correct. Soon you’ll learn what situations can fool your meter and when it can be trusted – and you’ll also learn when the Sunny 16 rule by itself is good enough.

About

Our ‘Absolute beginner’s guide to film photography’ is an educational series of articles focused on demystifying the ins and outs of analog photography. Geared toward those discovering (or re-discovering) film, the series will cover everything from gear, to technique and more. View all of the articles in our guide here.