Pinhole Photography for the DSLRScott HullGSFC Photo Club4/20/2011

HistoryAlso known as a camera obscuraEffect described as early as 5th century BCAristotle, Bacon, and da Vinci all studied itInitially a room, with the image projected on a wallPortable versions with projection screens for drawingFirst known pinhole photograph in 1850Popular mostly in late 19th centuryRevived in the 1960s for artistic purposesHas been used in spacecraft for X-ray imaging

Basic Idea

ResourcesCamerasMany are homemadeCommercial cameras are availableModifications for the DSLRPhotographic MediumFilmPhotographic paperCCDInformationDozens of web sitesVery big in the UK

Making the Aperture (1)MaterialsAluminum canAluminum foilBrass shim stockPunchNeedle or pinMounted in a pencil eraserCan be sharpened with sandpaperTechniqueThin the stock to weaken it, and provide better opticsPunch and twist, to get a round holeSand any burrs flat

Making the Aperture (2) http://www.alscotts.com/techniques/pinhole/

Practical AspectsDSLR makes things much easierLight meterHigh ISO values available for short exposuresFilm is cheapUse a tripod for long exposuresDust on the sensor is a big problemRemove with a low pressure puff of air (dont blow it!)Consider movement - blurringUsually not desirableCan be an interesting effect

My Examples0.16 mm aperture

Theoretical Optimum Hole SizeR = 0.95 ( d)R = radius of the hole = wavelength (550 nm average)d = focal distance (usually 50 mm)For most DSLRs, then R = 0.157 mm (hole diameter = 0.315 mm)Aperture: f = d/2R = f 159

Actual OptimizationSmaller is betterRoundness is criticalFlatness is important

Stock thickness has an effect as wellThinner is betterWider field of view with thinner stockvs.

Others Examples

More Examples

Extreme ExampleSIX MONTH exposure onto photo paperNotice the lines traced by the sun as it crossed the sky day after day, after dayhttp://www.geardiary.com/2010/07/28/photographer-uses-soda-can-camera-to-capture-6-month-long-exposure/

Worldwide Pinhole Photography Dayhttp://www.pinholeday.org/Last Sunday in April every yearApril 23 to May 1 this year, because of EasterTake as many images as you want, but only submit oneSubmit photos as a part of the Goddard Photo Club workshop: "NASA/Goddard:Greenbelt"