THE GOLDEN TRIANGLE > ISO > APETURE > SHUTTER SPEED

I have copied down some things from the web that I think you may

find helpful. Before you get to that I want to try and explain a couple

of things that we will be doing in our class.

SHOOTING At NIGHT WITHOUT A TRIPOD OR FLASH

First off let me give you this example of shooting at night without a

tripod and a flash. You’re walking down the street in YBOR and

you’re shooting in the Aperture setting. (Remember, the lower the

number i.e. f1.4, f2.8. f4.5 the more light in your camera. The higher

the number, f9, f11, f22, the less light.)

Set your camera in the Aperture setting to either f 4.5 if you want your

subject to be in focus and the background blurry, or f 9 or higher, if

you want everything in focus. Now you’re going to chase the light

exposure using only the ISO. Somewhere between 1600 and 3200

your shot will look like it was taken during the day! If it doesn’t keep

raising the ISO until it does. Remember, the higher the ISO setting

the more noise you will get and have to use a noise reduction

afterward in the editing process.

You don’t have to do anything with the Shutter Speed because when

you shoot in the Aperture Setting, the camera will automatically set

your shutter speed for you. Thank you camera!!!

LOW LIGHT WITH A TRIPOD, NO FLASH

You’re out and you are shooting the Tampa Skyline from Davis Island .

You always want to shoot in the Manual setting because the Aperture

setting will not give you a true color setting. When your camera is on

your tripod make sure that you turn off your shutter stabilizer or image

stabilization on your lens. Otherwise, your picture will be blurry when

you enlarge it.

Set your ISO on 100, you’re Aperture on say f-9 or f-11. You will

never touch them again as the only thing you’re going to move is your

Shutter speed. Depending on how dark it is you may set it for let’s

say 1 second. If your picture is too bright, turn it down less than one

second and keep going down until you have a properly exposed

picture. As the sky gets darker…., keep increasing the seconds to 2,

then, 3, then 4 as it gets darker and darker. That’s it!!! You now have

beautiful properly exposed night time low light photos!

STARBURST SPARKLE LIGHTS AT NIGHT

Again set your camera on Manual and then set your Aperture on f -14

to f-20 and above if you have anything higher. The higher, the better!

Let’s start at f-20 and then set your shutter speed to 30 seconds and

see what you get. If it’s too bright start lowering you shu tter speed to

25 seconds and keep going lower from there until you get the

exposure you want.

OR……

Go the other way….. keep your camera on 30 seconds and bring you r

Aperture down to say f-18 and keep going lower but do not go past f-

14 or you will lose the sparkle.

You can use a combination of both if you want as well. I prefer to

use the top one but practice this until you understand the results and

use whatever combination you like for your desired results.

FROM THE WEB.....

Adjustable elements that control the exposure - ISO, Aperture and

Shutter Speed.

1 What controls exposure?

ISO ratings determine the image sensor’s sensitivity to light, each value

of the rating represents a “stop” of light, and each incremental ISO number

(up or down) represents a doubling or halving of the sensor’s sensitivity

to light.

The Aperture controls the lens’ diaphragm, which controls the amount of

light traveling through the lens to the film plane. The aperture setting is

indicated by the f-number, whereas each f-number represents a “stop” of

light.

The Shutter Speed indicates the speed in which the curtain opens then

closes, and each shutter speed value also represents a “stop” of light. The

shutter speed is measured in fractions of a second.

When these three elements are combined, they represent a given

exposure value (EV) for a given setting. Any change in any one of the

three elements will have a measurable and specific impact on how the

remaining two elements react to expose the film frame or image sensor

and how the image ultimately looks. For example, if you increase the f -

stop, you decrease the size of the lens’ diaphragm thus reducing the

amount of light hitting the image sensor, but also increasing the DOF

(depth of field) in the final image. Reducing the shutter speed affects how

motion is captured, in that this can cause the background or subject to

become blurry. However, reducing shutter speed (keeping the shutter

open longer) also increases the amount of light hitting the image sensor,

so everything is brighter. Increasing the ISO, allows for shooting in lower

light situations, but you increase the amount of digital noise inherent in

the photo. It is impossible to make an independent change in one of the

elements and not obtain an opposite effect in how the other elements

affect the image, and ultimately change the EV.

I ISO Speed

ISO is actually an acronym, which stands for International Standards

Organization. The ISO rating, which ranges in value from 25 to 3200 (or

beyond), indicates the specific light sensitivity. The lower the ISO rating,

the less sensitive the image sensor is and therefore the smoother the

image, because there is less digital noise in the image. The higher the

ISO rating (more sensitive) the stronger the image sensor has to work to

establish an effective image, which thereby produces more digital noise

(those multi-colored speckles in the shadows and in the midtones). So

what is digital noise? It is any light signal that does not originate from the

subject, and therefore creates random color in an image. The digital

camera engineers have designed the image sensor to perform best at the

lowest ISO (just like with film). On most digital cameras this is ISO 100,

although some high end DSLRs have a mode that brings the ISO down to

50 or even 25.

A Aperture

A lens’s aperture is the opening in the diaphragm that determines the

amount of focused light passing through the lens. At a small f -stop, say

f/2, a tremendous amount of light passes through, even at a fraction of a

second; but at f/22, when the diaphragm is perhaps at its smallest, only a

tiny amount of light is let in (even at longer shutter speeds). An interesting

thing about the aperture and the f-numbers is that it doesn’t matter the

focal length of the lens as long as the f-number is held constant. This is

because the arithmetical equation that determines the f-number indicates

that the same amount of light passes through the lens on a 35mm lens as

on a 100mm lens, with a shutter speed of 1/125s. The size of the

diaphragm is unquestionably different, but the amount of light passing

through is the same.

S Shutter Speed

Shutter speed is measured in fractions of a second, and indicates how

fast the curtains at the film plane open and close. The shutter speed

controls how long light enters the lens and hits the image sensor or film

plane. The shutter speed enables you to capture the world in split

seconds, but it can also absorb the world at speeds upwards of three and

four seconds (or remain continually open up until the photographer wants

to close the curtain). Snapping the shutter in a fraction of a second, also

gives you control on how motion is recorded. If the shutter speed is faster

than the object or background, then the image will be tack sharp. If the

shutter speed is slower, then you’ll get blurred objects. Think about the

rain in a rainstorm, how fast is that water falling? Well, at 1/30th the

raindrops are streaks of undistinguishable white. But at 1/250th, the

raindrops hover in mid air and you can see the full swell of each water

drop.

2 What is "Auto Bracketing"?

Auto Bracketing is an exposure technique whereby you can ensure that

you have the optimal exposure by taking at least three (3) exposures of

the exact same composition with one at the metered EV, one at 1/3 of a

stop below the metered EV and one at 1/3 of a stop above the metered

EV. So “Auto Bracketing” is a function in which you set the EV value then

release the shutter and the camera automatically makes the necessary

up and down adjustments to the EV to give you the bracketed exposures.

Then you can review the three (or more) exposures, see the subtle but

critical differences in the images, and decide which one is the best image

for your purposes. In the three images on the right, you might prefer the

overexposed (by 2 stops) image because the setting sun is most brilliant.

Bracketing was a technique that was popularized from shooting slide film,

due to the limited ability to correct the image in the darkroom. Many

photographers still use the technique today, so they have the exposure

that they want. Having the three bracketed images lowers the amount of

post-processing time that they might have to spend.

3 Overexposure & Underexposure

How do you define overexposure and underexposure, since we said that

“correct” exposure is subjective? Simply put, overexposure is when the

information in the highlights is effectively unreadable. When there is this

type of excessive loss of image information there is no way to “retrieve”

that missing information in the digital dark room. Underexposure is pretty

much the same concept; except in this case there is no image information

contained within the shadows. This non-existent information cannot be

retrieved through post processing either. In digital photography, once that

image information is gone, there’s no way to retrieve it. This is not always

the case in the photochemical world of film photography. With film (as

opposed to digital) processing, it is possible to “find” image information in

an excessively underexposed frame, and perhaps “find” image

information during the printing process for seriously overexposed images

as well.

4 AE LOCK (AEL)

Auto Exposure Lock is a camera setting in which the EV is locked in (when

you’re shooting one of the semi-automatic or fully automatic modes, i.e.

Shutter-priority), so that no matter what changes there are to the lighting

in the scene, the camera locks in the ISO, Shutter and/or Aperture

settings, so you can continually achieve the same EV without having to

re-meter the scene.

C Conclusion

One highly practical advantage to digital photography is that it costs next

to nothing to experiment with the camera’s controls, so go out there and

shoot away. You want to become increasingly proficient with all three

elements of the exposure triangle, so that you can make adjustments on

the fly and know exactly what the resulting effect is going to be.