SHUTTER SPEED & F-STOPS

When you take a photo, the camera must let in just the correct amount of light to expose the film.

A LIGHT METER in your camera “reads” the amount of light in the scene toward which you are aiming the camera, and decides how much light needs to enter the camera to expose the film just right.

Too much light hitting the film makes the negative “overexposed” Too much light hitting the film makes the negative “overexposed”. It will be very thick and dark, and hard to print.

Too little light hitting the film makes the negative “underexposed” and it will be very thin and hard to see. The prints will be difficult to print also.

So, whether your camera is automatic or not, a light meter will read the scene, decide how much light is needed for your film speed and…..

either tell you by a meter reading in your camera ( a needle that moves up and down, or a red/green light, or a plus/minus sign) , or adjust itself automatically, for just the right amount of light to get a perfect negative.

ONE TYPE OF VIEWFINDER WITH METER READINGS ON RIGHT SIDE

You can learn how to control the amount of light yourself, so you can do creative things with your camera!

THERE ARE TWO WAYS TO CONTROL THE AMOUNT OF LIGHT THAT ENTERS A CAMERA

ONE WAY IS BY CONTROLLING THE LENS APERTURE THE SECOND WAY IS BY CONTROLLING THE SHUTTER SPEED

THE APERTURE OR F/STOPS CONTROLLER NUMBER 1: THE APERTURE OR F/STOPS

the LENS APERTURE ALLOWS LIGHT TO PASS THROUGH A LENS CARRYING THE IMAGE TO THE FILM IN THE CAMERA

AN IRIS DIAPHRAGM IS USED TO REGULATE THE APERTURE OPENINGS IT IS LOCATED WITHIN THE LENS. If you remove a lens on an SLR camera, you remove the aperture with it!

AN IRIS TYPE DIAPHRAGM IS MADE OF DELICATE AN IRIS TYPE DIAPHRAGM IS MADE OF DELICATE FLAPS THAT OVERLAP EACH OTHER

NUMBERS CALLED F- STOPS ARE USED TO MEASURE THE SIZE OF THE APERTURE OPENINGS

THE F-STOP NUMBERS ON YOUR CAMERA LENS

LOOKING THROUGH THE DIAPHRAGM AT DIFFERENT F/STOPS

THE APERTURE, OR F/STOPS, CONTROLS THE AMOUNT OF LIGHT GOING INTO THE CAMERA LIKE A FAUCET OPENING

THE WIDER THE APERTURE OPENING, THE MORE LIGHT WILL BE LET INTO THE CAMERA

IMPORTANT: THE F-STOP SYSTEM HAS BEEN DESIGNED SO EITHER TWICE AS MUCH LIGHT, OR HALF AS MUCH LIGHT PASSES THROUGH THE APERTURE AT EACH ADJACENT F-STOP.

AND F/4 LETS IN HALF AS MUCH LIGHT AS F/2.8 FOR INSTANCE, F/2.8 LETS IN TWICE AS MUCH LIGHT AS F/4 AND F/4 LETS IN HALF AS MUCH LIGHT AS F/2.8

CONTROLLER NUMBER 2: THE SHUTTER

A CAMERA SHUTTER IS LIKE A DOOR THAT OPENS AND CLOSES EITHER FAST OR SLOWLY

THERE ARE SEVERAL TYPES OF SHUTTERS THE SPEED AT WHICH THE SHUTTER OPENS AND CLOSES CONTROLS HOW MUCH LIGHT ENTERS THE CAMERA ALSO. THERE ARE SEVERAL TYPES OF SHUTTERS

A LEAF SHUTTER IS MADE OF THIN BLADES THAT FIT TOGETHER TO MAKE A ROUND OPENING YOU FIND THEM ON VIEWFINDER CAMERAS MORE OFTEN AS THEY ARE LESS COSTLY TO MAKE

PARTLYCLOSED PARTLY OPEN OPEN CLOSED CLOSED A LEAF SHUTTER HAS PRECISION THIN METAL OR PLASTIC BLADES THAT OPEN AND CLOSE RAPIDLY

A FOCAL PLANE SHUTTER IS USED MOST IN 35MM SLR CAMERAS THEY ARE MADE OF FABRIC OR METAL CURTAINS MOUNTED VERY CLOSE TO THE FILM PLANE

THE CURTAINS MOVE ACROSS THE FILM FRAME, ONE AHEAD OF THE OTHER THE CURTAINS MOVE ACROSS THE FILM FRAME, ONE AHEAD OF THE OTHER. WHEN THE SHUTTER RELEASE IS SQUEEZED, THE LEAD CURTAIN TRAVELS ACROSS THE FILM, FOLLOWED SHORTLY BY THE TRAILING CURTAIN. THIS ALLOWS LIGHT TO HIT THE FILM

THE SHUTTER SPEED DETERMINES HOW FAST THE CURTAINS MOVE IN RELATION TO EACH OTHER. THE FASTER THEY MOVE, THE LESS TIME THE FILM IS EXPOSED, AND SO THE LESS LIGHT REACHES THE FILM.

SLOW SHUTTER SPEED FAST SHUTTER SPEED

ONE SECOND IS VERY SLOW...WHERE 1/2000TH OF A SECOND IS VERY FAST. SHUTTER SPEEDS ARE MEASURED IN FRACTIONS OF A SECOND ONE SECOND IS VERY SLOW...WHERE 1/2000TH OF A SECOND IS VERY FAST.

SHUTTER SPEEDS ARE MARKED ON OR IN THE CAMERA ONLY BY THE DENOMINATION OF THE FRACTION A SHUTTER SPEED SETTING OF 250 REALLY MEANS THE SHUTTER OPENS AND CLOSES IN 1/250TH OF A SECOND.

THE SHUTTER SPEEDS ARE USUALLY SET BY A DIAL ON TOP OF THE CAMERA

SOME CAMERAS JUST HAVE AN LED DISPLAY FOR THE SHUTTER SPEED THE SHUTTER SPEED DIAL ON TOP OF A CAMERA LOOKS LIKE THIS SOME CAMERAS JUST HAVE AN LED DISPLAY FOR THE SHUTTER SPEED

THE SHUTTER SPEED WITH A DIFFERENT COLOR IS THE ONE YOU USE WITH A SEPARATE FLASH ATTACHMENT!!

SHUTTER SPEEDS

SHUTTER SPEEDS

JUST LIKE F-STOPS, ADJACENT SHUTTER SPEEDS EITHER HALVE OR DOUBLE THE AMOUNT OF LIGHT ALLOWED TO ENTER THE CAMERA

AND 1/60 LETS IN TWICE THE AMOUNT OF LIGHT AS 1/125 OF A SECOND SO, a 1/125 SHUTTER SPEED PERMITS HALF THE AMOUNT OF LIGHT AS 1/60 AND 1/60 LETS IN TWICE THE AMOUNT OF LIGHT AS 1/125 OF A SECOND

SO YOU SEE, YOU CAN CHANGE THE AMOUNT OF LIGHT THAT ENTERS THE CAMERA IN TWO WAYS: BY CHANGING THE F-STOP AND BY CHANGING THE SHUTTER SPEED

USING EITHER WAY, YOU CAN EITHER DOUBLE OR HALVE THE AMOUNT OF LIGHT THAT ENTERS FROM THE PREVIOUS SETTING.

SHUTTER SPEEDS AND F-STOPS HAVE A DIRECT RELATIONSHIP IN REGULATING LIGHT

YOU CAN HAVE MANY DIFFERENT COMBINATIONS OF SHUTTER SPEEDS AND F-STOPS THAT ALL LET IN THE SAME AMOUNT OF LIGHT!!!

THESE COMBINATIONS LET IN THE SAME AMOUNT OF LIGHT F-STOPS SHUTTER SPEEDS

THE COMBINATION OF THE F/STOP AND THE SHUTTER SPEED YOU USE TO TAKE A PICTURE IS CALLED THE “EXPOSURE” FOR THAT PHOTO.

SO, YOU MIGHT SAY, “MY EXPOSURE FOR THAT TRAIN PHOTO WAS F/4 AT 1/500 SEC.”

WHAT’S THE POINT!????

BY CHOOSING CERTAIN SHUTTER SPEEDS YOU CONTROL HOW MOVING OBJECTS APPEAR IN YOUR PHOTO (FREEZING MOTION, BLURRING MOTION, ETC.) 1/1000 sec 1/15 sec

BY CHOOSING CERTAIN F/STOPS, YOU CONTROL THE DEPTH OF FIELD IN YOUR PHOTO, OR HOW MUCH OF THE SCENE APPEARS IN FOCUS (LOTS OF DEPTH OF FIELD, NARROW DEPTH OF FIELD) f/2 f/16

IF YOUR METER TELLS YOU AN EXPOSURE IS CORRECT FOR A SCENE, YOU CAN CHANGE THE RESULTS WITHOUT CHANGING THE AMOUNT OF LIGHT ENTERING YOUR CAMERA.

IF YOU CHANGE TO A SLOWER SHUTTER SPEED, JUST CHANGE TO A SMALLER APERTURE TO COMPENSATE. SAME AMOUNT OF LIGHT….DIFFERENT EFFECT!!! GET IT?

AUTOMATIC CAMERAS WITH MANUAL OVERRIDE CONTROLS…WHAT YOU CAN DO

SOME CAMERAS ALLOW YOU TO CONTROL ONE OR THE OTHER AND IT AUTOMATICALLY CHOOSES THE COMPANION SETTING FOR THE CORRECT EXPOSURE.

IF YOUR CAMERA HAS THE SETTING: “P” = PROGRAMMED EXPOSURE, THEN THE CAMERA DECIDES AUTOMATICALLY WHICH F/STOP AND SHUTTER SPEED TO USE. YOU HAVE NO CONTROL, BUT THE FILM WILL BE EXPOSED CORRECTLY.

IF YOUR CAMERA HAS THE SETTING: “A” = APERTURE PRIORITY. YOU CHOOSE AN APERTURE OR F/STOP, THE CAMERA READS THE SCENE AND AUTOMATICALLY SETS THE CORRECT SHUTTER SPEED FOR THE FILM.

YOU CAN CONTROL DEPTH OF FIELD (HOW MUCH LOOKS IN FOCUS) WHILE STILL DEPENDING ON THE CAMERA FOR CORRECT EXPOSURE. DEPTH OF FIELD MOO IN FOCUS BLURRY BLURRY

IF YOUR CAMERA HAS THE SETTING: “S” = SHUTTER SPEED PRIORITY. YOU CHOOSE THE SHUTTER SPEED, THE LIGHT METER READS THE SCENE AND AUTOMATICALLY SETS THE CORRECT F/STOP FOR THE FILM.

YOU CAN CONTROL MOTION BLUR OR MOTION FREEZING, WHILE STILL DEPENDING ON THE CAMERA FOR AUTO EXPOSURE. HMM, SLOW SHUTTER OR FAST SHUTTER??

“M” = MANUAL SETTING. YOU CHOOSE BOTH F/STOP NUMBER AND SHUTTER SPEED. IF YOUR CAMERA HAS THE SETTING: “M” = MANUAL SETTING. YOU CHOOSE BOTH F/STOP NUMBER AND SHUTTER SPEED.

THE LIGHT METER READS THE SCENE AND TELLS YOU IF YOUR SETTINGS ARE TOO LITTLE, TOO MUCH, OR JUST THE RIGHT AMOUNT OF LIGHT FOR THE FILM. TOTAL CONTROL, BUT MORE ERRORS POSSIBLE. NOT ENOUGH LIGHT HITS THE FILM TOO MUCH LIGHT HITS THE FILM CORRECT EXPOSURE DARK NEGATIVE JUST RIGHT LIGHT NEGATIVE

FILM SPEED IS THE SAME, F/STOP IS THE SAME…BUT SHUTTER SPEED IS 1/30 SEC SHUTTER SPEED IS 1/125 SEC SHUTTER SPEED IS 1/60SEC

FILM SPEED IS THE SAME, SHUTTER SPEED IS THE SAME…BUT APERTURE IS F/5.6 APERTURE IS F/4 APERTURE IS F/8

F/STOP IS THE SAME, SHUTTER SPEED IS THE SAME…BUT ISO 800 ISO 400 ISO 1600

VERY WIDE DEPTH OF FIELD FROM A VERY SMALL APERTURE, SUCH AS F/22 OR F/16