Stopping down

In photography, stopping down refers to increasing the numerical f-stop number (for example, going from f/2 to f/4), which decreases the size (diameter) of the aperture of a lens, resulting in reducing the amount of light entering the iris of a lens.^[1]^[2]^: 112

Reducing the aperture size increases the depth of field of the image. In the case of film cameras, this allows less light to reach the film plane – to achieve the same exposure after stopping down, it is necessary to compensate for the reduced light by either increasing the exposure time, or using a photographic film with a higher film speed (ISO). In the case of digital cameras, stopping down the aperture allows less light to reach the image sensor – to achieve the same exposure, it is necessary to compensate for the reduced light by either increasing the exposure time, or increasing the signal gain of the sensor by increasing the camera's ISO setting. Alternatively, more light can be added to the scene by increasing the amount of light illuminating the scene, such as by using or increasing the strength of electronic flash or other light sources.^[3]

As a lens is stopped down from its maximum (widest) aperture, most lens aberrations (spherical aberration, coma and astigmatism) are decreased, but lens diffraction increases. The effect is that for most lenses, the balance between the decreasing aberrations and the increasing diffraction effects of stopping down the lens means that lenses have an optimum aperture for best results, often about three stops closed down from maximum aperture, so for a lens with a maximum aperture of ƒ/2.8, ƒ/8 would be the optimum aperture.^[2]^: 180

References

^ London, Barbara; Upton, John; Stone, Jim (2013). Photography (Eleventh ed.). Pearson Education Canada. ISBN 978-0205933808.
^ ^a ^b Allen, Elizabeth (2011). The Manual of Photography (10th ed.). Oxford: Elsevier/Focal Press. ISBN 978-0240520377.
^ Langford, Michael; Bilissi, Efthimia (2010). Langford's Advanced Photography (8th ed.). Oxford: Focal. ISBN 978-0240521916.

v t e Photography
Equipment	Camera light-field digital field instant pinhole press rangefinder SLR still TLR toy view Darkroom enlarger safelight Drone Film base format holder stock available films discontinued films Filter Flash beauty dish cucoloris gobo hot shoe lens hood monolight reflector snoot softbox Lens prime zoom wide-angle fisheye telephoto Manufacturers Monopod Movie projector Slide projector Tripod head Zone plate
Terminology	35 mm equivalent focal length Angle of view Aperture Backscatter Black-and-white Chromatic aberration Circle of confusion Color balance Color temperature Depth of field Depth of focus Exposure Exposure compensation Exposure value Zebra patterning F-number Film format large medium Film speed Focal length Guide number Hyperfocal distance Lens flare Metering mode Perspective distortion Photograph Photographer Photographic printing Photographic processes Reciprocity Red-eye effect Science of photography Shutter speed Sync Zone System
Genres	Abstract Aerial Aircraft Architectural Astrophotography Banquet Candid Conceptual Conservation Cloudscape Documentary Ethnographic Erotic Fashion Fine-art Fire Forensic Glamour High-speed Landscape Nature Neues Sehen Nude Photojournalism Pictorialism Pornography Portrait Post-mortem Ruins Selfie Social documentary Sports Still life Stock Straight photography Street Toy camera Underwater Vernacular Wedding Wildlife
Techniques	Afocal Bokeh Brenizer Burst mode Contre-jour Cyanotype ETTR Fill flash Fireworks Harris shutter High-speed Holography Infrared Intentional camera movement Kirlian Kite aerial Long-exposure Luminogram Macro Mordançage Multiple exposure Multi-exposure HDR capture Night Panning Panoramic Photogram Print toning Redscale Rephotography Rollout Scanography Schlieren photography Sabattier effect Slow motion Stereoscopy Stopping down Strip Slit-scan Sun printing Tilt–shift Miniature faking Time-lapse Ultraviolet Vignetting Xerography Zoom burst
Composition	Diagonal method Framing Headroom Lead room Rule of thirds Simplicity Golden triangle (composition)
History	Timeline of photography technology Analog photography Autochrome Lumière Box camera Calotype Camera obscura Daguerreotype Dufaycolor Heliography Painted photography backdrops Photography and the law Glass plate Visual arts
Regional	Albania Bangladesh Canada China Denmark Greece India Japan Korea Luxembourg Norway Philippines Serbia Slovenia Sudan Taiwan Turkey Ukraine United States Uzbekistan Vietnam
Digital photography	Digital camera D-SLR comparison MILC camera back Digiscoping Comparison of digital and film photography Film scanner Image sensor CMOS APS CCD Three-CCD camera Foveon X3 sensor Image sharing Pixel
Color photography	Color Print film Chromogenic print Reversal film Color management color space primary color CMYK color model RGB color model
Photographic processing	Bleach bypass C-41 process Cross processing Developer Digital image processing Dye coupler E-6 process Fixer Gelatin silver process Gum printing Instant film K-14 process Print permanence Push processing Stop bath
Lists	Most expensive photographs Museums devoted to one photographer Photographs considered the most important Photographers Norwegian Polish street women
Related	Conservation and restoration of photographs film photographic plates Lomography Polaroid art Stereoscopy
Category Outline

This photography-related article is a stub. You can help Wikipedia by expanding it.

This page was last edited on 23 April 2023, at 09:21

From Wikipedia, the free encyclopedia

References