Lens aper­ture, shut­ter speed and ISO are the three pri­mary adjust­ments avail­able to achieve a prop­erly exposed pho­to­graph. These set­tings can also affect the image qual­ity and artis­tic effects of your photography.

Lens Aper­ture

The aper­ture is the size of the open­ing in the cam­era lens at the moment a photo is taken.  Aper­ture is mea­sured in frac­tions, so the larger the num­ber, the smaller the aper­ture open­ing.  Shut­ter speed and aper­ture are the two pri­mary con­trols for lim­it­ing the amount of light that hits the cam­era sen­sor.  Aper­ture also con­trols the depth of field.  A small aper­ture will pro­duce a pho­to­graph with almost all objects in focus.  A large aper­ture will pro­duce a pho­to­graph with a small amount  of the objects in focus.  This will give you con­trol over what you want in focus. That is why I pri­mar­ily use the aper­ture pri­or­ity cam­era set­ting in my photography.

Typ­i­cal aper­tures include:   f1   f1.4    f2     f2.8     f4     f5.6    f8     f11     f16     f22     f23 f45

Cam­era Shut­ter Speed

Shut­ter speed is the amount of time the shut­ter remains open when a photo is taken.  Shut­ter speed and aper­ture together deter­mine just how much light hits the film or cam­era sen­sor.  The shut­ter speed is also a frac­tion, just like the aper­ture.  A shut­ter speed of 500 is actu­ally 1/500, or “one five hun­dredth of a sec­ond. To hand hold a cam­era, the rule of thumb is a 50mm lens can be hand-held at 1/60 of a sec­ond.  A 200mm lens at 1/200 of a sec­ond and so on.  To achieve this you can adjust the aper­tures or the ISO settings.

Typ­i­cal shut­ter speeds:  30s    20s    10s   4s   2s   1s   1/2s    1/4s     1/8s   1/15s    1/30s   1/60s   1/125s     1/250s     1/500s    1/1000s    1/2000s    1/4000s

Cam­era Sen­sor ISO

The sen­si­tiv­ity of film or cam­era sen­sor is mea­sured by ISO, and the larger the num­ber, the more sen­si­tive the cam­era sen­sor.  ISO 100 needs a lot of light, like out­doors on a sunny day.  ISO 1600 doesn’t need much light.  How­ever, higher ISO means more grain in the film and more noise in dig­i­tal.  Dig­i­tal images bor­row the ISO scale to mea­sure the sen­si­tiv­ity of film.  Just like the grain that’s added to film at higher ISO set­tings, more “noise” is added to dig­i­tal images at higher ISO.  In gen­eral, as ISO goes up, qual­ity goes down.  Some of the new mid to high-end D-SLR have improved the noise lev­els at the higher ISO set­tings up to ISO 1600.  Some of the new cam­eras have ISO set­tings between 100 and 102400.

Typ­i­cal ISO set­tings:   50   100   200 400   800   1600   and high ISO 3200 6400

Con­clu­sion

My basic cam­era set­tings I use related to this arti­cle  are: ISO 100 for best image qual­ity  and set cam­era to aper­ture pri­or­ity.  Also, use a tri­pod when ever pos­si­ble.  All three set­tings work in con­cert and affect proper expo­sure.  All have their advan­tages an dis­ad­van­tages, so exper­i­ment with all of  these set­tings and you will become a bet­ter photographer.

Ref­er­ence

Hear is a nice Expo­sure Chart

Doug Nie­der­miller Photography