VISUAL TECHNOLOGY PRODUCTION (MPT1483): March 2012

TOP PANEL CONTROLS

A, S and M Modes

If you want to use only one aperture or one shutter speed then use S or A mode and the camera will automatically pick the other value. I never use these; I shift the program instead.

If you want to set both the hard way, use M, manual, mode.

In A or S mode you can only set one of the two values because the camera is setting the other one for you.

A Mode: Aperture Priority

In A mode you choose the Aperture and the D40 chooses the shutter speed.

S Mode: Shutter Priority

In S mode you set the Shutter and the D40 sets the aperture.

If the D40 runs out of available apertures you easily can get under or over exposure in S mode: watch that the D40 can select a correct aperture for your lighting.

M Mode: Manual Exposure

You have to set everything the hard way.

No one uses this mode except in complex conditions. Ignore old-timers who tell you you need Manual mode; they say that because that's the only mode cameras had back in the 1950s.

I look at the LCD to check exposure. You can use the bar graph in the finder - but why? If you wanted to do that use another mode and let the D40 do the setting for you.

The rear dial sets the shutter speed in manual exposure. To set the aperture, hold the +/- (*) (diaphragm) button near the shutter and turn the rear dial.

Portrait Mode: This mode is ideal for taking portraits of people, or pictures where you want the background to blur to remove distractions that might interfere with seeing the main subject. This mode will automatically set the aperture to its widest available setting possible. The amount of blur will largely depend on the type of lens being used, and sometimes will depend on how close you're zoomed on the subject. Most zoom lenses will reduce the aperture when zoomed at its fullest setting, thus preventing blurry backgrounds.

Landscape Mode: Landscape mode tries to do the opposite of portrait mode. Instead of blurring the backgrounds, landscape mode will try to get as much in focus as possible. This setting is ideal for taking pictures of scenes or wide shots of large areas where everything should be in focus. In this mode, the flash will not pop up and fire because the camera assumes that the subject matter is too far away for a flash to be effective.

Close-up Mode: Close-up mode (sometimes called macro mode), is used for taking close-up pictures of subjects. This mode will adjust various attributes of the camera to prepare it for brining out the detail in close-up pictures. It also tones down the flash so it doesn't blow out the subject matter, as what typically happens in situations when the camera is too close to the subjects. Note that all lenses have a minimum focusing distance. This is the minimum distance the lens can physcially be to the subject before the lens can no longer show the subject in focus. For some zoom lenses, this can be a long distance. In these cases, it's best to zoom in as much as possible while keeping the subject in focus.

Sport Mode: This mode is used for taking pictures of quickly moving subjects. It works best outdoors or when there is a lot of light. It attempts to reduce the amount of motion blur as much as possible by using high shutter speeds. Sport mode will always be restricted by the amount of available light in the scene, and when its too dark, motion blur may be introduced into the system.

Night Portrait Mode: Night portrait mode is a mode for taking a very specific type of picture. It's used for taking pictures at night, with a flash and using a tripod. Night mode attempts to bring out the background lights that often are lost when using flash photography at night. It's important to note that if you don't use a tripod with night mode, your photos are likely to end up blurry.

What is a DSLR (Digital SLR)?

DSLR stands for “Digital Single Lens Reflex”. In simple language, DSLR is a digital camera that uses mirrors to direct light from the lens to the viewfinder, which is a hole on the back of the camera that you look through to see what you are taking a picture of.

1) What do DSLR cameras consist of?

Take a look at the following image of an SLR cross section (image courtesy of Wikipedia):

2) How do DSLR cameras work?

When you look through the viewfinder on the back of the camera, whatever you see is exactly what you are going to get in the photograph. The scene that you are taking a picture of passes through the lens in a form of light into a reflex mirror (#2) that sits at a 45 degree angle inside the camera chamber, which then forwards the light vertically to an optical element called a “pentaprism” (#7). The pentaprism then converts the vertical light to horizontal by redirecting the light through two separate mirrors, right into the viewfinder (#8).
When you take a picture, the reflex mirror (#2) swings upwards, blocking the vertical pathway and letting the light directly through. Then, the shutter (#3) opens up and the light reaches the image sensor (#4). The shutter (#3) remains open for as long as needed for the image sensor (#4) to record the image, then the shutter (#3) closes and the reflex mirror (#2) drops back to the 45 degree angle to continue redirecting the light into the viewfinder.
Obviously, the process doesn’t stop there. Next, a lot of complicated image processing happens on the camera. The camera processor takes the information from the image sensor, converts it into an appropriate format, then writes it into a memory card. The whole process takes very little time and some professional DSLRs like Nikon D3s can do this 11 times in one second!
The above is a very simple way to explain how DSLR cameras work.

F-Stop, Aperture and Depth of field

Aperture

Aperture is the size of the opening of the lens when a picture is taken. Whe you hit the shutter release button on the camera a hole opens up that allows the image sensor to catch a glimpse of the scene you are wanting to capture. The aperture that you set affects the size of the hole.

The smaller the hole the less light gets in (shallow depth of field making the image in the foreground in focus and the background fuzzy).

The larger the hole more light gets in (large depth of field means most of your image is in focus wether its close to the camera or far away) .

Aperture is measured in F Stops - f/2.8, f/4, f/5.6,f/8,f/2

Aperture has a big impact upon depth of field. Large aperture (remember it’s a smaller f stop number) will decrease depth of field while small aperture (larger numbers f stop number) will give you larger depth of field. Small numbers mean small DOF and large numbers mean large DOF.

DEPTH OF FIELD/ APERTURE EXAMPLE SHOTS

Large Depth of field = higher f stop number = small aperture

Shallow depth of field = F Stop 5 = large aperture

Where to Find the Aperture

All lenses have a maximum aperture, and all NIKKOR lenses list the widest possible aperture on the lens barrel. Some zoom lenses will detail something like f/3.5-5.6 on the lens barrel or 1:3.5-5.6 (below right). These numbers, the 3.5 and the 5.6, are referring to the maximum aperture or widest opening the lens can achieve for each end of the zoom range. Some higher end lenses can maintain the largest aperture throughout the entire zoom range, so only one number is detailed (below left).

Shutter Speed

What is SHUTTER SPEED?

Wikipedia describes shutter speed as being the amount of time a digital cameras shutter is held open for when taking a photograph. Shutter speed allows light to reach the cameras image sensor.

In photography, shutter speed is a common term used to discuss exposure time, the effective length of time a camera's shutter is open. The total exposure is proportional to this exposure time, or duration of light reaching the film or image sensor.

Shutter speed is measured in seconds and looks like 1/500, 1/250, 1/2 or 1 as in one second etc. It can range anywhere from 1/8000 to B for bulb. Bulb keeps the shutter open for as long as the shutter button is pressed down.

How do we know what shutter speed to use?

The shutter speed we will need to use depends on the type of photograph we want to take. For example, if we want to take a photograph of water frozen in action with every little bead in focus, then we would choose a fast shutter speed like 1/500 of a second. If we want to blur running water like the example below, then we would need to use a slower shutter speed like 1/4 of a second. Often when we use a slow shutter speed, we will also need a tripod to help avoid camera shake.

Caspian Tern - 1/250 of a second @ ISO 800

Caspian Tern - 1/2000th of a second

Short tips for using shutter speed in digital SLR photography

Slow shutter speed, slows motion.
Fast shutter speed, takes the image almost instantly as in frozen in time.
Use slow shutter speeds of at least 10 seconds or more for night shots of cities, buildings and streets etc.
When using a slow shutter speed it's also a good idea to use a tripod and remote shutter release to avoid camera shake.
If for any reason we don't want to use a tripod, then a general rule to avoid camera shake is to never set our shutter speed slower than the reciprocal of the focal length value. For example, if our lens focal length is set at 50mm then don't use a shutter speed any slower than 1/60th of a second and so forth.
To photograph a running child or animal while blurring the background, set the shutter speed to between 1/40 sec and 1/125 sec. Then follow the running child or moving animal as we press the shutter button. This is often referred to as panning.

White Balance

Preset White Balance Settings

Auto – this is where the camera makes a best guess on a shot by shot basis. You’ll find it works in many situations but it’s worth venturing out of it for trickier lighting.

Tungsten – this mode is usually symbolized with a little bulb and is for shooting indoors, especially under tungsten (incandescent) lighting (such as bulb lighting). It generally cools down the colors in photos.

Fluorescent – this compensates for the ‘cool’ light of fluorescent light and will warm up your shots.

Daylight/Sunny – not all cameras have this setting because it sets things as fairly ‘normal’ white balance settings.

Cloudy – this setting generally warms things up a touch more than ‘daylight’ mode.

Flash – the flash of a camera can be quite a cool light so in Flash WB mode you’ll find it warms up your shots a touch.

Shade – the light in shade is generally cooler (bluer) than shooting in direct sunlight so this mode will warm things up a little.

Preset White Balance

Digital cameras also have presets white balance options: sunlight and cloudy for outdoor and fluorescent, incandescent and tungsten bulb for indoor in case you need them. These will compensate the yellow or blue tint. Here are some examples for these on Canon PowerShot A520, indoor conditions.

Auto White Balance

Situations when auto white balance will not likely work proper are: beaches (yellowish tin), snow (bluish tin), cloudy weather, indoor photography, but also forests. This is why a lot of cameras have scene modes for these cases.

Here are several examples of comparison pictures using white balanced :

ISO

ISO denotes is how sensitive the image sensor is to the amount of light present. The higher the ISO, the more sensitive the image sensor and therefore the possibility to take pictures in low-light situations.

ISO speed affects the shutter speed / aperture combinations we can use to obtain correct exposure.

Suppose our digital camera's light meter warns us there is not enough light to correctly expose a scene. We could use the on-board flash, but let's suppose again it's not allowed.

We would then need to use a higher ISO. Set on "ISO Auto" mode, Our digital camera will automatically select a higher ISO. Otherwise, We can manually select the next higher ISO and see if the increased sensitivity allows us to obtain a correctly exposed picture. If it does, we can now take a correctly exposed picture.

However, all this increase in sensitivity does not come free. There is a price to pay with our image appearing more noisy.

General Rules and tips for ISO Settings:

Use an ISO of 100 or 200 when taking photographs outside in sunny conditions.
If the sky is overcast or it is evening time, then use an ISO within the range of 400 to 800.
Night time or in cases of low light you might need to set your digital camera ISO to 1600. If we don't then our photo will appear too dark if at all.

Examples of different settings of ISO

ISO Setting: 200

ISO Setting: 1600

Week 1:

Clarification of course syllabus, teaching and learning strategy, assignments and project guidelines.

Assignment 1 – Digital Image Album

Individual Project

consists of:

i. Realistic Images produced by using DSLR

(minimum 8 images – 2 portrait images, 4 landscape images, and 2 macro images). Each image has to be explained with the exposure setting (Aperture, Shutter Speed, ISO) that has been used.

ii. At least six images with incorrect exposure and shooting techniques and the corrected version of the images with the correct exposure and shooting techniques.

Portrait Images

Image 1