F16 Sunny Rule For Exposure

The f16 Sunny Rule is a simple exposure guide for setting the correct exposure on your camera when photographing  subjects lit by sunlight. The rule says when photographing at f16, the correct shutter speed is the reciprocal of the ISO setting. For example, when photographing at f16 and using an ISO of 100, the correct shutter speed is 1/100 (1/60 when using a mechanical camera). It's that simple.


When photographing in shade, use a 18% gray card or light meter.

Nikon D600 with 105mm lens f11 1/50 second and Polarizing filter and yes a good tripod. Remember to slow the shutter speed two stops when using a polarizing filter.

F16 Sunny Rule When Using 100 ISO

Lens                   Digital Camera          Mechanical Camera

Aperture            Shutter Speed           Shutter Speed

f22                            1/50                            1/30

f16                          1/100                            1/60

f11                          1/200                          1/125

f8                            1/400                          1/250

f5.6                         1/800                          1/500

f4                          1/1600                        1/1000

f2.8                       1/3200                        1/2000

F16 Sunny Rule When Using 400 ISO

Lens                   Digital Camera          Mechanical Camera

Aperture            Shutter Speed           Shutter Speed

f22                            1/200                            1/125

f16                            1/400                            1/250

f11                            1/800                            1/500

f8                            1/1600                          1/1000

Fine Tuning The f16 Sunny Rule

In most cases, the f16 sunny rule works perfectly. Some films and digital cameras are not accurate for the ISO that is selected.


For example, Kodak TMax 100 black and white film works best when set to ISO 64. Yes there can be variations on film developing but in general, 64 ISO is suggested.

For other films please call us.


I have also found that some digital cameras are not accurate. To find your own f16 rule, photograph a scene that is in full sunlight with lots of colors and tones in the photo. Try also to include a good white and black for reference.

Set your ISO to 100

Shoot a series of exposures:
f16 at 1/50

f16 at 1/60

f16 at 1/90

f16 at 1/100

f16 at 1/125

f16 at 1/160

Now look at the test photos on your computer monitor (assuming your monitor is not to old and worn out and has been warmed up a bit).

Pick the best looking photo to your taste. That selected shutter speed is your f16 rule.

Questions or comments?

Give us a call at 920-733-5885 or Email: pmurraympv@aol.com

If this has helped you, please let us know on our Facebook page.

This site was designed with the
website builder. Create your website today.
Start Now