example,thewayinwhichtwolensesatthesameƒ-stop
willrecordanimagewillbedifferent,andassuchlens
choice should be considered along with depth of field.The wider aperture (smaller numbers such as ƒ1.4 and
ƒ2.8)willgivetheimagea shallowdepthoffieldanda
smaller area of the image will be visually sharp. The
smalleraperture(highernumberssuchasƒ22andƒ32)will
givetheimagealongerdepthoffield,wherealargerarea
oftheimagewillbevisuallysharp.Creativelytheseratios
canbeusedtogreateffectwithdifferentialfocusingand
selective focusing.
Aswiththestandardizationoftheshutterspeedvalues,the
introductionofauniversallyconsistentwayofrepresenting
thefocallengthmakesthesystemalittleeasiertograsp,
with each major step exactly doubling or halving the
amountoflightenteringthecamera(ƒ1.4,ƒ2.8,ƒ4,ƒ5.6,
ƒ8,ƒ11,ƒ16,andsoon).Aspreviouslystatedthesecanbe
workedeffectively in conjunctionwith theshutterspeed
values to create the desired effect.
Thethreevariables–ISO,shutterspeedandƒ-stopvalues
- when used correctlyand with in-depth understanding,
will allow the photographer to fully control the light
enteringthecameraandtoobtaintherequiredresultsfrom
a capture, with well-constructed and considered choices
being made. Teaming this knowledge with the sound
understanding of which lenses to select and utilize in
certain situations will allow the photographer the most
creative input.