Diamond P Photography
by James Gault of Park City Utah 801-755-6737

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What is an " aperture " ? Aperture is referred to the lens diaphragm opening inside a photographic lens. The size of the diaphragm opening in a camera lens REGULATES amount of light passes through onto the film inside the camera the moment when the shutter curtain in camera opens during an exposure process. The size of an aperture in a lens can either be a fixed or the most popular form in an adjustable type (like an SLR camera). Aperture size is usually calibrated in f-numbers or f-stops . i.e. those little numbers engraved on the lens barrel like f22 (f/22),16 (f/16), f/11, f/8.0, f/5.6, f/4.0, f/2.8, f/2.0, f/1.8 etc. Each of this value represents one time the amount of light either more or less in quantity. Meaning to say, f/16 will let in 1X the amount of light than a diaphragm opening of f/22 and so forth; while on the other hand, an aperture of f/4.0 will let in 1X lesser than that of f/2.8 etc.

Note : the diaphragm blades inside this manual focus Canon FD lens control the amount of light passing through the lens that eventually hitting to the film during an exposure process. The ' amount ', or simply explained in layman term - opening changes according to selection of aperture (f/number). In this case, it is indicated by the f-numbers that imprinted on the lens barrel.

These numbers engraved on the lens barrel are NOT referred to aperture diaphragm, but rather just a numeric settings which help to let you determine and control how much light you would require to let into the camera by way of selecting an aperture diaphragm ( lens opening inside ). Technically, these numbers refer to the relative physical opening of the lens diaphragm

Modern Autofocus SLR cameras may have a different ways in manipulating the aperture. One of the trend is - the aperture value is now control via a thumb wheel on the camera (usually near the shutter release button) and the AF lens has no aperture ring to alter the value. Each camera manufacturer usually has their own series of lenses under a trade name to verify its usage, various compatibility issues with their previous camera model's function etc. For an instance, Canon manual focus lenses are called " FD " or "FL"; while their newer series of autofocus lenses ( AF ) designed for their Canon EOS Series cameras are referred as " EF " (Electro Focus). Each of these MF/AF lenses has their own respective way to illustrate the control of aperture in the camera. When you turn the aperture ring on a lens to vary the aperture, you will be able to check visually the set opening of the lens diaphragm (Opens bigger or stopping smaller) . * here in this section, I am confining the discussion within the MANUAL FOCUS lenses ONLY because the proportion of used equipment forms the basis for a cheap, easy entry for potential new serious photographers.

* Some lenses such as those made by Canon (See above), the lens diaphragm will not react to turning, unless you press the aperture pin.

There are many camera brands out in the market, thus, it is indeed very difficult for me to compile all of the labels into a single site. Anyway, I am using three popular camera brands to illustrate the whereabouts of these aperture on the lens. ( A ) is a typical FA lens by Pentax ; ( B ) is a typical manual focus Nikkor zoom lens from Nikon ; while the ( C ) is a Zuiko lens by Olympus .

Reminder:- the key to an theoretical good EXPOSURE = Aperture + Shutter speed

Aperture value ( s ) :	f/64, f/32, f/22, f/16, f/11, f/8.0, f/5.6, f/4.0, f/2.8, f/2.0, f/1.8/f1.4 etc. ( WE ARE HERE )	Control via the lens section
Shutter speed (s) :	1/8000, 1/4000, 1/2000, 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8, 1/4, 1/2, 1 sec, etc.	Control via the Camera section

Remember : For a theoretical "perfect" exposure to be formed i.e. nice colour balance, every details shown or simply a photo that you are happy about, take a good combination between using an aperture with the appropriate matching shutter speed for any given film speed (ASA/ISO) are required. The latter refers to the film speed of the film roll used. i.e. ASA 100, ASA 200, ASA 400 etc. the faster the film speed used, you can use to capture lower lighting situation but at the expense of grainer output of prints / slides. Next, a little confusion may create for you to learn here: - each step increment in the use of film speed will also indirectly correspond with one step of aperture OR shutter speed .

I know you must be asking a mind boggling question while you read until here: Ooi....HOW THE HELL WOULD I KNOW WHAT APERTURE TO SET on my lens when I take a picture ? Frankly, you need not have to ! Inside any modern camera, there is a metering cell residing internally which measures the light intensity of the scene you are trying to capture/pointing to. Its metering circuitry will SUGGEST an exposure for you. For an instance, the exposure suggests by the camera's internal metering circuitry indicates 1/125 sec. (camera) with f/8.0 (lens) will deliver a decent exposure for your intended capture. You can override the camera setting (depends on whether the camera has such option for you to manipulate the aperture on the lens OR shutter speed on the camera, most P&S don't offer such options but a SLR camera usually does). For an example, change the f/8.0 to f/4.0 (let in more light by 2 steps 4.0-->5.6-->8.0) and compensate the shutter speed by few stops by limiting light entering the camera shutter i.e. 1/125--->1/250--->1/500. The compensated 2 steps on the shutter speed still delivers the SAME EXPOSURE as the earlier camera suggested reading. The difference is now with a f/4.0, you can achieve a narrow Depth of Field (refer to below WHY and WHAT difference it will bring to your picture with such alternation)..

However, the MOST confusing part for any new photographer is: Just remember in photographic term: a BIG aperture is actually referring to a smaller number engraved on the aperture ring of the lens i.e. f/1.4, f/2, f/2.8, f/4.0 etc. while small apertures mean bigger numbers i.e. f/22, f/16, f/11, f/8 etc. Once you have "overcome" such " mental block " in calculation, it should help you greatly understand / enjoy reading more in other sections that follow. So, it is important that you OUGHT to digest this paragraph . ( CLICK HERE to understand the relation of those numbers found on the lens where how the lens diaphragm inside at each aperture set. Well, I am not sure who was the hell was the bloody smart guy who first started by inverting the number on the aperture on the lens - where small number (f/2.0, f/2.8 etc.) is actually referring to a larger lens opening while big number(s) such as f/11, f/16, f/22 etc. is actually smaller aperture. Basically, large aperture (f/2.0, f/2.8 etc.) lets in more light to the camera shutter for an exposure, while small aperture (f/11, f/16, f/22 etc.) has a smaller opening in the lens diaphragm to let in LESS light for a given exposure. The confusion usually causes a beginner who might be poor in mathematics gives up serious photography from here @#$^*#&*!!. Well, I guess you are not within that figures-fophia group, so - why don't just be patience and spends a few minutes to DIGEST this part. Trust me, it worth the time and could reward you with plenty of joy with the camera you own.

About aperture and its direct relation that might affect in your photography:- i.e. Other than controlling the amount of light entering into the camera, What else does "apertures" do ?

When the shutter button is released, light passes through the aperture diaphragm and hit the film, an exposure is formed. Basically, aperture, along with duration/timing of the shutter curtain opening, BOTH contribute to a the formation of an exposure. But aperture also affects an important photographic element called " depth of field " (short form "DOF"). You may ask, what is hell is this " Depth of Field " ? Depth of field is just technical term used to describe the 'zone' of sharpness' between nearest and furthest of a subject in focus (to be more exact, distance of sharp focus in front and behind, subject on which the lens is focused).

There are a few elements that will affects Depth of Field in a picture
( Note :- Factors on lens ONLY, shutter speed never affects depth of field):

1. 1	the lens opening (diaphragm inside the lens)		the bigger the apertures used, the zone of sharpness is shallower or vice versa i.e. smaller aperture used will has extended depth of field
   2	the focal length of the lens (50mm as standard , 80mm above as telephoto ; 35mm or shorter as wideangle )		wide angle lenses have extended field of sharpness than a longer focal length telephoto lenses and/or longest reach focal length on your zoom lens), and
   3	the distance from the lens to the subject		the nearer the subject is, the shallower the zone of sharpness and vice versa.

	< <-- creative use of picture frame in composition and small aperture to gain maximum depth of field.
PhilipChong ( 41k ) Shallow depth of field with combination of close focus with a telephoto lens and a fairly large aperture may limit the zone of sharpness to minimal. MORE illustrations	MC Lau ( 43k ) Top and Bottom:- Typical scenic pictures with a smaller aperture to gain extended depth of field (sharp zone of focus)	PhilipChong ( 44k ) Lovely blur out (depth of field) on distracting background via use of a combination of telephoto lens with a large aperture which draws viewer attention to the main subject.
CY Leow ( 52k )

In fact, if you still don't understand, just memorize this: Other than it can be used to regulate amount of light entering into camera for an exposure, aperture also will affect the degree of depth of field. When combined with other essential elements that may also contribute to depth of field changes, such as focal length of the lens in use, the distance of your object in focus, you can make use of depth of field for creative control in your photography. For example: use larger aperture (Smaller number like f/2.8, f/2.0 etc.) with a long focal length to isolate or emphasis on expression, such as in portraiture photography ; or use a smaller aperture (Bigger number like f/16 or f/22 etc..) to ensure pin-sharp details in both the foreground and the background .

Another factor you need to know is: All the markings on the lens barrel are double in effect . i.e. f/11 doubles the amount of light of f16, f2 allows 1X more light than of f2.8 does into the camera etc.

With a mechanical SLR camera, with the proper exposure GUIDE suggested by the built-in meter in a camera, you need to adjust both aperture and shutter speed yourself (it is termed as " MANUAL " setting in an automatic camera) . Usually in the case of an automatic camera, you will still have manual control operating as if you are using a mechanical camera. Typically, a few extra choices of exposure control methods may be provided:- the first is called " Aperture Priority " (some camera uses a symbol " Av " - short for "aperture value"; the next is " Shutter Priority " ( Tv - short for "Timing value". Aperture priority means you select the aperture to determine the depth of field yourself and the camera will set to the appropriate shutter speeds to match your aperture selected for a optimum exposure suggested by the camera's built-in electronic metering circuit, while shutter priority will let you select the preferred shutter speed setting and the camera will select the matching aperture values to match your choice. The third option is called the " Programmed Mode"( P - short for "Programmed Auto", where the camera select both the aperture value and the shutter speed for you and you may have no control in determine the depth of field yourself. (some cameras offer a another mode called flexi-program - I think it is too complicated to explain here).

Some examples of how an APERTURE PRIORITY AUTO SLR-type cameras shutter speed ring look like
and comparison made with a fully mechanical SLR type (below - far right)

Nikon F3 Top Av auto SLR models of yesterdays: -Other examples are: Pentax LX	Nikon FE2 Other examples like the Olympus OM2n and Canon AV-1	Nikon FA This is a Multi-modes auto SLR. The ring doesn't have an "A", various modes ae at the side P, S, A and M (Manual)	Nikon FM2n The Shutter Speed ring of a MECHANICAL / NON-AUTO SLR. no Auto selection button or setting. You need to set the shutter speed on the camera section along with the aperture on the lens. Other brands such as Pentax offers K1000, Olympus has an OM-1 etc.

Newer range of autofocus SLR cameras use a new method of controlling aperture. You will find there is NO NEED to set aperture via the lens aperture ring; instead - aperture is controlled by the thumb wheel for BOTH shutter Speed ( B ) and Aperture ( A ). A method first pioneered by Canon on their manual focus Camera, the Canon T90 back in 1986. Although this new electronic input method is different from older SLR cameras, the principle remains the same. The VISIBLE confirmation of the selected aperture used on camera like this type is via the LCD on the top panel OR through the viewfinder.

Note: An exposure control ring found in many modern SLR. The various setting may be represented by a few symbols/letters, " P " is for "Programmed AE", the " Tv " is for shutter priority while the Av (aperture value) is referring to aperture priority - Canon's way of interpreting in their A and T series camera bodies. IF you are a owner of one of those SLR cameras, you can CLICK HERE to find out the exact model you are using. While Nikon Owner may use THIS SECTION OR you may find the specific camera models that I might have developed with a featured section.

Every camera manufacturers have different design of how to adjust shutter speeds with a dedicated AF lens. For an example, Nikon's Nikon F5 , 1996/7 finally followed Canon's path in using wheel input for shutter speed and aperture control; followed by its next generation AF film/digital-based SLRs which resulted in newer AF G-series Nikkor lenses now has NO aperture ring on the lens barrel for controlling aperture. However, if an older manual focus Ai lens is used in manual or aperture priority AE mode, it will still operate as an conventional SLR in which you will still make use of the lens aperture scales. Time changes, methods alter but basic principle remains.

I strongly advise you to consume this section first before you think of proceeding to the next segment on shutter speeds . If you can't ,or finding difficulties digesting what I have prepared here, I'm sorry for my failure in explaining the essentials. In such cases, I would suggest you to buy a better illustrated photographic reference book or join a local photographic club. But if you do understand and have picked up something from this section, you are encouraged to click at the button underneath and continue...

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What is shutter speed ? The aperture diaphragm of a lens (bigger or smaller values) AND timing (open and close) of the camera's shutter curtain - BOTH perform the tasks of regulating the amount of light entering the camera and expose onto the film . The shutter speed scales engraved on the shutter speed dial of conventional camera bodies with a shutter speed ring OR via some flickering digital numerals on the LCD screen like: 1/8000, 1/4000, 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8, 1/4, 1/2, 1 or -1, -2 etc. are essentially indicators of the duration (timing) at which the shutter curtain opens up and closes during an exposure process. A 1/125 setting means the shutter curtain open and close within one hundred and twenty five of a second while 1 means an one full-second the shutter opens up during exposure to absorb the available light source onto the film to form an exposure .

The shutter speed dial provide the selection of shutter speeds, and indicates the timing of the shutter open and closes. A fast shutter speed such as 1/500 sec will close faster than, say 1/2 sec exposure time. In this case, the shutter curtain will close very fast and thus resulting in less light entering the film. Illustration used here is a older horizontal shutter design, more info is available by < clicking here > .

Most conventional SLRs have a shutter speed dial (or ring) on the top panel of the camera body to adjust shutter speed. But it evolves with the development of modern electronic SLRs.

Before the advent of LCD, multi-modes electronic SLRs such as Canon A-1 has a dual input dial for shutter speed ( B ) and aperture control (Green). But again it depends a lot on camera design. For an instance, ALL Olympus and mechanical Nikkormat SLRs have their shutter speed scales located just next to the lens mount, you have to make use of a grip designed to turn the scales ( A ) !

Again, NOT all SLR cameras have shutter speed selected visible from the top or the front, instead, changes and selection can only be viewed inside the viewfinder. A good example is this Pentax push button that controls ( C ) the shutter speed.

But ALL these may not be applicable to a new wave of modern AF SLRs which use a different kind of input to control shutter speed in the camera. Most would have use thumb or finger wheel(s) such as illustrated earlier on the aperture control section. Well, it is hard to cover and satisfy everybody's desire all in a single page, and my prime interest is still to selling you the idea of how to make use of an old, cheap manual focus SLR of yesteryears. As for an modern AF SLRs, there are plenty of useful resource sites on the Net for you to browse through and gather such information. At this moment in time, I won't be able to offer too much of a help here in this site. But whatever it is, basic principle remains.

What does shutter speeds do ?

In principle, shutter speeds, like aperture value detailed on earlier section , contributing as the next half of the main components for any exposure process - the interval at which the shutter opens to allow a specific amount of light (also depends on the opening of the lens diaphragm) to pass through and expose the film inside. .

Different selection of shutter speeds will yield different kind of visual effect on a final photograph. Generally, a fast shutter speed can freeze action while slow speed can blur your image . I am not indicating these are fixed rules. If you understand the nature of how various shutter speed(s) will affect an exposure, you may put them to creative use to enhance the effect - like other than freezing a fast action scene, a slow shutter speed can also put to good use in portraying movement. You can try on to " PAN " a moving subject by following its direction or simply generates a sense flow of movement. But MOST people relates SLOW means BLURRING AN IMAGE which leave little for them to select this alternative to try them out. Well, it is excusable because in most PR -type of photography ( photo session on public relation matters like wedding, gathering, seminars, or personal domestic duties for some privileged group - includes your wife, mistress or girl friends ..), who would appreciate a defocus or blurry images ? BUT - for the creative minded photographer, slower shutter speed sometimes may create a more powerful visual impact than images taken with action-freeze high shutter speed (s), say, a free flowing river, traffic, a flock of birds taking off or even speed-demons on a race track.. etc..

A basic mechanical SLR camera body like the Nikon F2S of the mid-seventies only offers manual exposure control. AE may require accessory such as DS-1 to transform it into an shutter priority AE camera.

A camera operating in manual mode or a mechanical camera requires you to set the shutter speed and aperture value on the lens manually. In an automatic camera, there is usually at least one type of automatic exposure mode is available. Because of complication of mechanism involves, most camera manufacturers offer only Aperture Priority AE or Programmed AE modes on their EARLY electronic camera models. A good example is Minolta and Canon with their MD and FD mount cameras and lenses while in some exceptional case, such automation was made possible using a mechanical device such as Nikon's F2 with their EE Aperture Control Unit. However, by early '80 with development and refinement made on both cameras and lenses (Most would require a new series of optics), majority of them started to offer " Shutter Priority AE " and " Intelligent Programmed AE " as well.

OFF-TOPIC SUPPLEMENTS: " Shutter Speed Priority AE ": An exposure mode with an automatic or autofocus camera that lets you select the desired shutter speed; the camera will then set the matching aperture value for a proper exposure. If you change the shutter speed, or the light level changes, the camera adjusts the aperture accordingly " Aperture Priority AE ": An exposure mode on an automatic or autofocus camera that lets you set the aperture while the camera sets the shutter speed for a proper exposure. If you change the aperture, or the light level changes, the shutter speed will change automatically. Apart from the sport or action photography, aperture priority is the most common & effective automatic mode used in photography. It can also explained as: An automatic exposure process in which the lens aperture is set by the photographer, and the camera sets the shutter speed. It can also be used in the stopped-down mode with any lens that does not interfere with the metering system e.g. bellow unit or non-auto extension rings etc. " Programmed AE ": An exposure mode on an automatic or autofocus camera that automatically sets BOTH aperture and shutter speed for a proper exposure. " Intelligent / Flexi-Programmed (flexible-Programmed Auto) AE ": The camera's electronic circuit will determine based on the information gathered from the lens coupling to provide HIGHER shutter speed in a program mode if a long focal length lens is used to minimize chances of image blur caused by slow shutter speed. In most cases, Aperture Priority AE is usually represented by a " A "; Shutter Priority AE is represented by "Tv" or "S"; while Programmed AE is denoted as a simple "P" or "P H " in a high speed program AE mode.

Picture courtesy of Vincent Thian , AP; Nick Kalatha , US and Swan pictures by David Hofmann , Germany

Selection of FAST or SLOW shutter speeds may yield different visual effect in a photograph
basically, it is FREEZE or MOTION CREATING. The FREEZE can also be use to minimize hand shake, the BLUR may be use for artistic effect; in some situations, you may use slow shutter speed because the permitting ASA/ISO range of the film in use or aperture on the lens are at their limit. The swan pictures by David was a very good example as side by side comparison between sue of HIGH shutter speed and LOW speed is used.

Beginning with some highly successful AE camera models that was very well received during the mid-seventies (a very good example is a shutter priority AE mode, Canon AE-1 camera that has sold more than 5 million units worldwide !), camera manufacturers realized the inevitably route to AE which resulted to a huge volume of automated SLR camera models flooding onto the market during the early seventies. These newer range of camera models usually came with all the essential automatic exposure control modes mentioned earlier within a single body, either fitted with buttons or with exposure information display through LEDs or LCDs panels.

With just a twist of a button, you can convert your camera into either shutter or aperture priority mode or a more sophisticated multi-programs AE. Such complexity in the exposure control also demands a new method of display essential exposure information and/or other camera functions. The conventional analog method was best represented with camera model such as Canon A-1 of 1977 (which has its aperture set on the dial instead of turning the aperture ring on the lens) or a refined method used in multi-modes SLR camera such as the Nikon FA in 1983. (See earlier Notes )

Beginning with the Nikon F3 in 1980, camera manufacturers found a new flexible and more power efficient way in LCD (Liquid Crystal Display) to handle the increasingly complex camera functions. An illustration below was from an autofocus Nikon F90x camera, the LCD display was in full display status (In practice, it will only show related information relates to an exposure or status quote of the camera in operation). The Canon T series models like the Canon T-70 at left has more than 5 automatic exposure modes with power film advance and rewind feature built-in. LED display is used in the viewfinder information display, while a large LCD panel is a top of the camera body.

Modern AF cameras, with a wealth of sophisticated features incorporated within, are more complicated, as shown is a full featured LCD screen. Substituting all conventional mechanical dial and levers by computer circuits. So, gone are the traditional shutter dial or ring on the camera. Highlighted part represents usual location (generally big and bolder numerals or figures) of the digitally displayed shutter speeds OR aperture values.

Some SLR cameras like the FD-mount Canon Canon T-80 even has LCD's "pictograph" to help the photographer in each of the exposure control mode or progress status. IF you owns a modern autofocus SLR camera, the display can even be more confusing (but most often the LCD willnot shown all the info except for related characters for any particular shooting modes used):

| CLICK HERE FOR AN NEW WINDOW |
TO SEE HOW A MODERN CAMERA LOOKS LIKE IN ITS VARIOUS FUNCTIONS AND CONTROLS.
The camera is a professional grade Canon EOS-1N . Others may or may not share the same form and appearance.

Confusing ?
No. As I said earlier the display system ONLY SHOWS related data directly associates with a particular shooting mode and exposure. Other info for adjustment may also be shown but it is less clustered as illustrated here.

Well, All you need to digest from this SHUTTER SPEED section is:

Shutter speed is, apart from aperture, the other main component required to form a proper exposure. It is control by the shutter speed dial. Shutter speed means timing and duration of opening and closing of the shutter curtain at the back of the camera. A fast shutter speed will freezes action while slower speed creates blurring effect. A shutter speed of 1/125 will allow one time more the amount of light to reach the film than 1/250, the amount of light is double on the next scale of 1/60 to 1/125 etc.

Since both the aperture and shutter speed control amount of light reaches the film for a exposure, there is a very strong relationship between the two :

1. The aperture (how big or small the lens diaphragm inside a lens opens up) allows different amount of light falls onto film through the lens that attached on your camera body and;
2. The shutter speed (the shutter curtain - duration and how long it opens up to absorb the amount of light falls onto film);

Although mechanically it differs in function and operation, but the objective is the same - both control and regulate light reaching the film plane to provide a proper exposure.

So, the next section, we will talk about exposure.

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A command dial commonly found in current Canon's AF EOS SLR cameras are a newer way of input and selection of various camera function. Conventional way of setting aperture value on the aperture ring on the lens is not required unless you are in manual override mode. Other manufacturer such as Nikon has also followed this method in their newer series of AF SLR cameras, where your pointer finger is used for controlling input such as aperture value and the thumb is used for shutter speed selection.

What is an Exposure ?

It can be explained as the quantity of light allowed to act on a photographic material; a product of the intensity (controlled by the lens opening) and the duration (controlled by the shutter speed or enlarging time) of light striking the film or paper (darkroom or in the color-lab).

Viewing, metering through the Lens (TTL)	Mirror flip-up, Lens diaphragm stopped down, light reaching the film exposure is formed		Shutter curtain closes, reflex mirror stays down, back to TTL viewing

First, you MUST understand a fact, i.e. there is no such thing call a " perfect exposure ". It is all a matter of personal preference - well, only the photographer who did the image capture process will "hold" the rights and judge whether it is or it is not a "good" exposure. Virtually all modern cameras have a reflective photo cells (see SPD or Cds ) built in to give you a indication what a recommended proper exposure is - basing on the brightness of the scene with the type and speed of the film in use. The term "proper exposure" is built around a reference where the photo cell read a 18% gray reflectance (most neutral in photography and resemble most outdoor environment) and give you the "suggested" reading (you may override those values).

Exposure can a very subjective matter . I would think it is more like a personal interpretation. In this series of three pictures on the magnificent Kuala Lumpur City Centre (KLCC) beside my office (once the tallest human-made structure as at year 2003). I preferred the center image as the start-off photo for my first of the Asia Landmark series .

If you trust the meter reference and happy with it, just trip the shutter release button, and here you go, you got a photograph with proper exposure (don't worry, unless you are using slides, most modern print film have enough exposure latitude in tolerance of your mistake in exposure reading).

Shown at right is a typical focal plane shutter curtain for a SLR camera, it can be either horizontal traveled or traveled vertically to protecting film from fogging during viewing and metering; it will open during an exposure process (The span of time opens depending on your selected shutter speed); this combines with the aperture opening on a lens to form an exposure.

The correlation between shutter speed and aperture size is a direct one. Since both the aperture and shutter speed (forget about the elements of depth of field, action freezing or movement by blur factors) control the amount of light reaching onto the film. And since both double or reduce in a scale of one time ( 1X or 100%): It means you can FREELY interchange the settings on shutter timing and lens opening for respective effects and YET retaining your preferred exposure setting.

Aperture value ( s ) :	f/64, f/32, f/22, f/16, f/11, f/8.0, f/5.6, f/4.0, f/2.8, f/2.0, f/1.8/f1.4 etc.	Control / adjust via the lens section *
Shutter speed ( s ):	1/8000, 1/4000, 1/2000, 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8, 1/4, 1/2, 1 sec, etc.	Control / adjust via the Camera section

* Referring to older manual focus-type SLRs only. Newer series of AF SLRs may have it controlled via camera body via Sub-Command Dial

For an example, let us just take an example with a scene of waterfall, the camera meter reading suggested a exposure of f/8 at 1/125 sec., your preferred effect is to freeze every single droplet of water to show the power of the waterfall, with a setting of 1/125, you may not achieve that kind of effect, but a shutter speed of 1/2000 may be able to convey that effect. Just set the camera's shutter speed dial to '2000' (1/2000 sec - just compensate it with five steps in shutter speed scale ) with the reduction of light of five steps by open the lens aperture bigger by five steps; in this case, i.e. f/2.0. Now you are using a alternate combination of f/2 at 1/2000 sec. while the exposure is still equivalent to f/8 at 1/125 sec set earlier BUT the eventual effect of the photograph varies now with what you have envisioned to achieved. On the other hand, if the same scene needs to portray a sense of poetic movement, you may adjust the speed down to, let's say, 1/8 sec to make the waterfall have a sense of flowing water. The uncompensated figure for aperture might cause over exposure (from 1/125sec to 1/8 sec., there are four step down, more light will reach the film and cause overexposure).

In this case, by adjusting the selected aperture to reduce the same equivalent amount of light to i.e. f/32 can retain the same exposure and yet achieve of what your desire - a free flowing waterfall. The photo shown at left is another picture to illustrate an example of creative combination use between selection of a SLOW shutter speed with a flash to create certain visual effect. Credit : Image courtesy of Mr. Jochem Wijnands ® Credit : Image courtesy of Mr . Manuel Angel Toral Fernandez ® . images. Image copyright © 2005. All rights reserved.

If, for an instance, an exposure combination of 1/15 second on the shutter speed scale and an aperture value of f22 setting on the lens is needed, the aperture would get wider as the shutter speed increases. e.g. 1/15 sec at f/22 = 1/30 second f16 = 1/60 second f11 = 1/125 f /8. Note:- N ewer series of AF SLR camera that only has LCD display, the dial in front of the LCD is dedicated for variable apertures selection - such a design is commonly found on modern autofocus cameras.

Depth of field ("DOF")also plays an very important part of the creative segment in photography. It has a direct relationship with aperture value selected (the other two factors affecting depth of Field are being the focal length of the lens in use plus distance of the subject from the camera). When you understanding these factors, creative use of depth of field can add a lot of depth in your photography especially involve very much in the field of portraiture, travel, product and scenic photography. You can select a bigger aperture (Smaller number such as f2.0, f1.4 etc.) to throw undesirable background out of focus and thus put more emphasize on your subject of interest in a photograph. On the other hand, if the background of a scene is equally important or the subject is a group of people or objects at different distances from the camera where each one must appear sharp, a small aperture (f16, f22 etc.) can be used to make sure from near to far will appear in pin-sharp focus.

You MUST understand the compensated combination between apertures and shutter speeds in order to put them to good use. Most often, we always heard photographers complaining: "what turned out are different from what I saw inside the viewfinder during that moment...". Although it forms only a segment of how it can influence a eventual image, but you can get close to your desirable effect in your photography if you have a good knowledge of how each of these elements may affect your photography. Still confuse ? Let take an example, e.g. to throw all the undesirable background out of focus, select a larger aperture. We use a meter reading of f/8 at 1/125 sec. for discussion here, an aperture of f2 might achieve better result than a f8 for this purpose, but the selection requires you to compensate for the increase of light by four steps, it means unless you reduce the light by means of increasing the shutter speed to four steps in equivalent, your photograph will be over exposed. Thus, from f8 at 1/125 sec, the exposure is the same as f/2 at 1/2000 sec while you can have your background blurred out.

i.e. f /8 at 1/125 sec = f/5.6 at 1/250 sec = f/4 at 1/500 = f/2.8 at 1/1000 = f/2 at 1/2000.

Lastly. after all this explanation; all you need to know is, for an example, a photograph taken at 1/4000 sec. and f/1.4 and one taken at 1/30 sec. and f/16 will have the same exposure value. However: the eventual effect in your photo taken with the respective choices on shutter speed selection (on camera) and/or aperture selected (on the lens) will be totally different.

A short Summary on the few sections in this site :

Shutter speed ( s ) (Duration/timing of the shutter curtain closing inside the camera section) :
It controls the degree of movement in your pictures (fast speed to freeze a movement or slow speed to create creative motion effect).

Aperture ( s ) (lens section) :
It determines the depth of field (zone of sharpness in front and behind) of the focus subject of interest. It adds depth and dimension in your photos.

Exposure :
Camera metering circuitry suggests an exposure (combination of shutter speed set in your camera + aperture selection on lens). User decides whether to override camera's metered / suggested combination for specific effect in the final image based on personal interpreation best expressing his/her thought.

1)Q:Want flowers in foreground with a mountain in the back?
A:Use the Av setting. Use the highest possible setting. you will need to be on a tripod.

2) Q: Take a picture of Bull Riding.
A: use Tv setting with the highest possible number before it starts blinking. you need to get to 1/60 to 1/250 or better. you may have more luck chaging the iso setting to 800 or 1600.

3) Potriat hints. A solid background with put the focus of the viwer on the subect. you can use all kinds of colors as long as it is ust one color =)