page_title: Sunny 16 rule
hierarchical_section_title: Sunny 16 rule
caption_attribution_description: English: Tessina with exposure guide plate
context_page_description: In photography, the sunny 16 rule is a method of estimating correct daylight exposures without a light meter. Apart from the obvious advantage of independence from a light meter, the sunny 16 rule can also aid in achieving correct exposure of difficult subjects. As the rule is based on incident light, rather than reflected light as with most camera light meters, very bright or very dark subjects are compensated for. The rule serves as a mnemonic for the camera settings obtained on a sunny day using the exposure value system.
  The basic rule is, "On a sunny day set aperture to f/16 and shutter speed to the [reciprocal of the] ISO film speed [or ISO setting] for a subject in direct sunlight." For example:
  On a sunny day and with ISO 100 film / setting in the camera, one sets the aperture to f/16 and the shutter speed to or seconds.
  On a sunny day with ISO 200 film / setting and aperture at f/16, set shutter speed to or.
  On a sunny day with ISO 400 film / setting and aperture at f/16, set shutter speed to or.
  As with other light readings, shutter speed can be changed as long as the f-number is altered to compensate, e.g. second at f/11 gives equivalent exposure to second at f/16.
context_section_description: In photography, the sunny 16 rule (also known as the sunny f/16 rule) is a method of estimating correct daylight exposures without a light meter. (For lunar photography there is a similar rule known as the looney 11 rule.)  Apart from the obvious advantage of independence from a light meter, the sunny 16 rule can also aid in achieving correct exposure of difficult subjects.  As the rule is based on incident light, rather than reflected light as with most camera light meters, very bright or very dark subjects are compensated for.  The rule serves as a mnemonic for the camera settings obtained on a sunny day using the exposure value (EV) system.
  The basic rule is, "On a sunny day set aperture to f/16 and shutter speed to the [reciprocal of the] ISO film speed [or ISO setting] for a subject in direct sunlight."  For example:
  On a sunny day and with ISO 100 film / setting in the camera, one sets the aperture to f/16 and the shutter speed (i.e. exposure time) to  or  seconds (on some cameras  second is the available setting nearest to  second).
  On a sunny day with ISO 200 film / setting and aperture at f/16, set shutter speed to  or .
  On a sunny day with ISO 400 film / setting and aperture at f/16, set shutter speed to  or .
  As with other light readings, shutter speed can be changed as long as the f-number is altered to compensate, e.g.  second at f/11 gives equivalent exposure to  second at f/16. More in general, the adjustment is done such that for each stop in aperture increase (i.e., decreasing the f-number), the exposure time has to be halved, and vice versa. This follows the more general rule derived from the mathematical relationship between aperture and exposure time—within reasonable ranges, exposure is proportional to the square of the aperture ratio and proportional to exposure time; thus, to maintain a constant level of exposure, a change in aperture by a factor c requires a change in exposure time by a factor  and vice versa. I change in the aperture of 1 stop always corresponds to a factor close to the square root of 2, thus the above rule.
  An elaborated form of the sunny 16 rule is to set shutter speed nearest to the reciprocal of the ISO film speed / setting and f-number according to this table:
caption: Tessina with exposure guide plate from the 1960s. At that time, DIN 21 was equivalent to ASA 80. After 1983, DIN 21 was ASA 100.[5] On this guide plate, DIN 21 uses f/16 and 1/125, consistent with Sunny 16.
exif: {"Image Make": "Panasonic", "Image Model": "DMC-FZ40", "Image XResolution": "180", "Image YResolution": "180", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Ver.1.0", "Image DateTime": "2016:02:18 20:51:36", "Image Artist": "Picasa", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "642", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 50, 53, 48, 0, 0, 14, 0, 1, 0, 22, 0, ... ]", "Image Tag 0xC6D2": "[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ... ]", "Image Tag 0xC6D3": "[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ... ]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "2790", "Thumbnail JPEGInterchangeFormatLength": "8804", "EXIF ExposureTime": "1/60", "EXIF FNumber": "37/10", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "320", "EXIF SensitivityType": "Standard Output Sensitivity", "EXIF ExifVersion": "0230", "EXIF DateTimeOriginal": "2016:02:18 20:42:31", "EXIF DateTimeDigitized": "2016:02:18 20:42:31", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "4", "EXIF ExposureBiasValue": "0", "EXIF MaxApertureValue": "3", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Flash", "EXIF Flash": "Flash fired, auto mode", "EXIF FocalLength": "134/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "1500", "EXIF ExifImageLength": "1373", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "Interoperability RelatedImageWidth": "4320", "Interoperability RelatedImageLength": "2880", "EXIF InteroperabilityOffset": "2642", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "0", "EXIF FocalLengthIn35mmFilm": "155", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "High gain up", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal", "EXIF ImageUniqueID": "acc6c41b41f0b818c45ecdefa5310456"}