Revision KNEC Questions and answers on Photography Technology

Macrophotography and microphotography are two types of photography that focus on capturing images at different scales. Here are the distinctions between the two:

Macrophotography:

Macrophotography involves capturing highly detailed and magnified images of subjects at a relatively large scale. It focuses on capturing small subjects or details of larger subjects that are not easily visible to the naked eye. The primary objective of macrophotography is to showcase intricate details, textures, and patterns that may go unnoticed in regular viewing.

Key characteristics of macrophotography include:

Subject Size: Macrophotography typically captures subjects that are larger in size, ranging from a few centimeters to a few meters. Examples include flowers, insects, jewelry, small objects, and textures on larger objects.
Magnification: Macrophotography employs specialized lenses, extension tubes, or close-up filters to achieve high magnification and capture fine details. It allows photographers to capture subjects at a 1:1 or greater magnification ratio, reproducing them at life-size or larger.
Depth of Field: Due to the close proximity to the subject, macrophotography often has a shallow depth of field. This means that only a small portion of the image is in sharp focus, while the rest gradually blurs, creating a pleasing bokeh effect.

Microphotography:

Microphotography, on the other hand, involves capturing images of extremely small objects or subjects at a microscopic scale. It requires the use of specialized equipment, such as microscopes or macro lenses with extension tubes, to achieve high magnification and capture subjects that are not visible to the naked eye.

Key characteristics of microphotography include:

Subject Size: Microphotography captures subjects that are typically microscopic in size, such as cells, microorganisms, tissues, or tiny structures within objects.
Magnification: Microphotography utilizes high-powered microscopes or specialized lenses capable of capturing subjects at magnifications higher than what is achievable with macrophotography. It allows for detailed examination and documentation of subjects at a cellular or subcellular level.
Depth of Field: Microphotography often faces challenges in achieving a sufficient depth of field due to the high magnification and close proximity to the subject. Techniques like focus stacking or image stacking may be used to capture multiple images at different focal planes and combine them to create a final image with extended depth of field.

In summary, macrophotography focuses on capturing highly detailed images of relatively larger subjects, while microphotography specializes in capturing subjects at a microscopic scale, revealing details that are not visible to the naked eye.

Describe a dark room factors that would lead to poor quality print

The dark room must be totally devoid of any light , presence of any unwanted light would interfere with the development process of the photograph.
Lighting in a dark room should be of appropriate quality that will enhance production of quality photos.
The lighting which consists of the white light, should be positioned within easy reach so that there is no trouble reaching for it in the darkness.
In addition, a well-mounted safe light should be positioned over the developing tray to enable monitoring of developments
The room is divided into two; i.e. dry bench and wet bench
The wet bench is used for all those processes that involve use of liquids / chemicals while the dry bench is used for those activities that use electric appliances e.g. enlarging and drying. This benches should be correctly identified and separated from each other in order to avoid contamination of items used during development of photographs.
The room should also be scrupulously clean and free from any dust particles that can lodge on surfaces of the printing papers which could destroy the emulsion-coated side of the printing paper

Distinguish between a single lens reflex (SLR ) and a Twin lens reflex (TLR) camera

In the single-lens reflex camera, the photographer sees the scene through the camera lens. This avoids the problem of parallax, which occurs when the viewfinder or viewing lens is separated from the taking lens.
Twin-lens reflex cameras used a pair of nearly identical lenses, one to form the image and one as a viewfinder. The lenses were arranged with the viewing lens immediately above the taking lens. The viewing lens projects an image onto a viewing screen, which can be seen from above.

State the purposes of a camera lens

A camera lens (also known as photographic lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically or electronically.
A lens is a tool used to bring light to a fixed focal point. In a film camera, the lens sends the light to the film strip, while in a digital camera (like DSLRs or mirrorless cameras), the lens directs light to a digital sensor. Camera lenses are made up of a series of glass plates that are convex (curved outward) or concave (curved inward)

Explain the following camera characteristics

All lenses filter and focus light so that it hits the sensor or film strip correctly. However, there are a variety of other factors that determine how a camera lens affects the look and quality of the final photo.
Focal length is the measurement of distance (in millimeters) between the point of convergence of your lens and the sensor recording the image. The focal length range of a lens is expressed by a number, and that number tells you how much of the scene your camera will be able to capture. Smaller numbers have a wider angle of view and show more of the scene; larger numbers have a narrower angle of view and show less.
Aperture is how big the opening is that lets light in, expressed in f-stops. F-stops are counterintuitive, because the larger the number, the smaller the opening. For example, f/2.8 allows twice as much light into the camera as f4, and 16 times as much light as f11. Aperture affects the depth of field: larger openings create a shallower depth of field, while smaller openings make more of the image in focus.
Maximum Aperture. Lenses will list a maximum aperture on the barrel, indicating the maximum width a lens aperture can open. Typically, lenses with a wider maximum aperture cost a bit more. A lens with a wide maximum aperture is great for low light situations, so if you are considering night photography, it might be worth the investment.
Depth of Field. Controlling the amount of the photo that is in focus is one of the photographer’s best tools to help draw the viewer’s eye where you want it. For example, landscapes are typically shot so that everything is in focus, so photographers will shoot at small apertures (e.g. f11 or f16). The depth of field varies with the type of lens, due to maximum aperture.

List three types of camera lenses

There are two basic categories of camera lenses:

Prime lenses. Primes have a fixed lens focal length, making them faster and sharper. While prime lenses are less flexible due to the fixed focal length, they are also fast and lightweight, making them easy to travel with
Zoom lenses. Zooms use a series of lenses to allow different focal lengths from a single lens, making them more flexible but not as fast. They contain more glass, which aids in their flexibility, but they also tend to be bigger and heavier than prime lenses.

Within both prime and zoom types of lenses, there are a variety of lenses, all with different focal lengths.

Macro Lenses

This type of camera lens is used to create very close-up, macro photographs. They have a unique design that allows them to produce sharp images at extremely close range. These lenses are great for nature photography, enabling you to capture an enormous amount of detail in one image.

Telephoto Lenses

Telephoto lenses are a type of zoom lens with multiple focal points. These types of lenses are great for isolating a subject that is far away. However, such great magnification comes at the price of a narrower field of view. In the same way that you would use a telescope to look at stars and planets, a telephoto lens is used for focusing in on distant objects. Many sports photographers use telephoto lenses to provide a sense of intimacy with the subjects on the field (the players) while standing on the sidelines or in the bleachers. There are many different types of telephoto lenses, and some can be quite large, heavy, and expensive, so take some time in choosing the right telephoto lens.

Wide Angle Lenses

Wide angle lenses are ideal for fitting a large area into your frame. This is especially useful for landscape photography or street photography. With wide angle lenses, almost everything is in focus, unless your subject is very close to the lens.

Standard Lenses

Standard lenses can be used for a variety of different types of photography. Their focal lengths fall somewhere in the middle, usually between 35mm and 85mm. A zoom lens within this range will have a small enough focal length at the bottom end to take a wider angle, full-frame photo, and a large enough focal length at the top end to zoom in on subjects.

Specialty Lenses

Finally, there are some more specialized camera lenses that can impart a unique look and feel to your photographs. There are several types of specialty camera lenses, but a few of the most prominent examples are:

Fisheye lens. A fisheye lens is an ultra-wide-angle lens that can take in a full 180 degree radius around it. Fisheye lenses are so named because they distort an image’s field of view, making even a room in a house look like a bubble.

Tilt shift lens. A tilt shift lens distorts perspective, making things look smaller than they really are—almost as if they are toys.

Infrared lens. These lenses play with light rather than perspective, filtering out all light waves except infrared for a unique visual effect.

Describe how the following camera controls works
1. Aperture

An aperture is simply a small hole or opening into the camera, which allows light to get in. The size of the aperture and the brightness of the scene controls the amount of light that enters the camera during a period of time

The lens aperture consist of overlapping movable leaves which forms a diaphragm set to different ranges of diameters so that the quality of light admitted is controlled. Apertures control the amount of light reaching the film. The size of the aperture can be controlled depending on the amount of light present i.e. large aperture used for dim light and small aperture used when there is bright light.

Shutter

A shutter is simply a knob at the top of the camera, which is normally pressed when taking an exposure. The shutter controls the length of time that the light hits the recording surface Shutters not only control the exact moments when the film is exposed to light but also the duration of exposure i.e. the amount of light that is admitted .the length of time the shutter remains open controls the quantity of light that reaches the film. Shutters are fitted within or just behind the lens body and use a set of blades, which rapidly opens or shuts. They sometimes consist of two separate blinds positioned just in front of the film.

Depth of field

Depth of field is the distance within which objects appear clear and sharp.

Differentiate between film speed and shutter speed

Shutter speed is the speed in which the shutter opens and closes the aperture to allow light to enter through the lens
Film speed refers to the amount of sensitivity of the film to light , the faster the film speed, the less exposure needed to be given to light. Film is given in A.S.A (American standard association) or DIN number (for Europe) e.g. the film marked 400 ASA is twice as sensitive as that marked 200 ASA film. These mean doubling the ASA number doubles the film speed or its sensitivity toward light

State four care and maintenance of a camera

Keep your camera clean at all times. Always use a dry, clean cloth when wiping the outside of the camera. And never use any harsh cleaners or solvents to clean and wash any of the parts.
When cleaning, you can use a blower, brush, soft lint-free cloth, or lens cleaning paper. If you are not familiar with cleaning the lens and the inside parts, it is better to take it to a service company for professional cleaning. Do not poke the inside of your camera with your fingers or blow on it, as it could cause damage.
Camera batteries should also be given utmost care and attention. They should not be overcharged or left exposed to high temperatures.
Batteries should be stored in a cool, dry place and recharged when not used for a long time. Remove the battery from the camera before storing both, especially if you are not planning to use it for a long time.
Store your camera in a cool, dry, and airtight place. When storing your camera in a cabinet, make sure it is not warm and humid inside. Take note, humidity and condensation are enemies of the camera.
Keep the lenses covered at all times when not using the camera. It is better to remove all the components of the camera and cover them individually.
Also, avoid placing your camera near any magnetic source, as this could have damaging effects on the camera’s LCD, memory card, and battery. Check your camera’s user manual for further recommendations on how to store your camera.

describe double lens camera as used photography

A twin-lens reflex camera (TLR) is a type of camera with two objective lenses of the same focal length. One of the lenses is the photographic objective or “taking lens” (the lens that takes the picture), while the other is used for the viewfinder system, which is usually viewed from above at waist level.

Name factors that affect film exposure time

Exposure is the result of three different variables that determine if your photo is under-exposed (too dark), over-exposed (too bright), or evenly exposed. The three variables that make up exposure are Sensitivity, Shutter Speed, and Aperture.

Sensitivity refers to how sensitive the camera’s digital sensor (or film) is to light and has been expressed in different ways including ASA and ISO.
Shutter Speed is a measure of how long the camera’s sensor is exposed to light. Shutter speeds are measured in seconds or fractions of a second.
Aperture is the size of the lens opening that allows light to pass through and reach the camera’s sensor.

Any Change in one of these elements will change the exposure of your image.

Discuss the composition of solutions used for film processing

Developer solution
Fixer solution
Stop bath solution

Explain the use of the following solutions in photography
1. Fixer solution

Used to make the remaining silver salts to be insensitive to any further exposure to light. This makes the image permanent and light resistant by dissolving the remaining silver halides.

Developer solution

Changes silver ions on the film into black metallic silver which creates the film image.

Stop bath solution

Used to halt the development process to prevent the picture from becoming darker

Describe using a labeled diagram of the chemical layers of a black and white a film used in photography

The light sensitive chemical is coated on the front surface while its back surface is coated with anti-halation dye, which is black, and thus prevents light reflecting off the sheet into the light sensitive layer on the front surface

The diagram below shows a section of a black and white photographic film

State the function of each parts labeled

Black and white film generally consists of a minimum of five layers:

A thin clear gelatin layer without any additions which serves as a protective layer against mechanical damage;
The light sensitive layer consisting of a suspension of silver salts in gelatin (the actual emulsion). It may have been coated on in one or multiple layers;
The adhesive substratum which binds the emulsion to the base;
the base or support consisting chiefly of nitro-cellulose (nitrate film) or acetyl-cellulose (triacetate, safety film);
There may be a further layer for anti-halation purposes; or a coating of gelatin to prevent curling; or a layer which serves both of these purposes.

Outline the precautions necessary when handling developer solution in a dark room

When handling developer solution in a dark room, several precautions should be taken to ensure personal safety and maintain the quality of the solution. Here are some necessary precautions to consider:

Personal Protective Equipment (PPE): Wear appropriate PPE, including gloves, goggles, and a lab coat or protective clothing. This helps protect your skin, eyes, and clothing from potential contact with the developer solution.
Ventilation: Ensure proper ventilation in the dark room to minimize the buildup of fumes or vapors from the developer solution. Open windows or use an exhaust fan to allow fresh air circulation.
Lighting: Use safe, dim red or amber lighting in the dark room. These colors do not significantly affect the photosensitive properties of the developer solution, unlike white light. Avoid exposing the developer solution to bright light sources, as it can prematurely develop or ruin the photosensitive materials.
Handling and Spills: Handle the developer solution with care and avoid any spills or splashes. Use appropriate containers or bottles with secure lids to prevent leakage. In case of spills, clean them up immediately using absorbent materials and dispose of them properly according to local regulations.
Mixing and Dilution: Follow the manufacturer’s instructions for mixing and diluting the developer solution accurately. Use the recommended water-to-solution ratio and avoid any deviations or substitutions unless specifically instructed.
Storage: Store the developer solution in tightly sealed, labeled containers in a cool, dry place, away from direct sunlight or heat sources. Check the expiration date and discard any expired or degraded solution.
Chemical Incompatibilities: Be aware of any chemical incompatibilities with the developer solution. Avoid mixing it with other chemicals unless specifically instructed by the manufacturer or expert guidance.
Disposal: Dispose of the used developer solution according to local regulations and guidelines. Do not pour it down the drain or dispose of it in regular waste bins unless approved by the appropriate authorities. Follow proper disposal protocols to minimize environmental impact.

Emergency Preparedness: Familiarize yourself with the location of safety equipment, such as eyewash stations and fire extinguishers, in the dark room. Have a clear understanding of emergency procedures and contact information for immediate assistance, if needed.

It’s important to note that the specific precautions may vary depending on the type of developer solution and the specific dark room setup. Always refer to the product instructions and adhere to established safety protocols to ensure safe handling and use.

List steps involved in processing a black and white photographic film.

Film processing should be done in a light-tight closet or black fabric-changing bag called development tank..

Once the film is in the developing tank, the preceding processes can be carried out in the open daylight or normal light. The following chemicals are used in film processing

Developer solution
Fixer solution
Stop bath solution

The already diluted solution i.e. developer, stop bath and fixer solution can now be used in systematic sequence i.e.

Pour the solution in the tank, holding the tank at an angle to allow air to escape. Start the timer and agitate as instructed by the manufacturer. Tap the tank to dislodge air bubbles, then close the cap and then turn the tank over and back at half an hour interval throughout the development time.
At the end of the development time, pour the developer solution out and fill it again with the stop bath solution for 10 sec then leave the tank to stand in warm water for 1 min.
Pour out the stop bath; you can now use water at room temperature. Fill the tank, agitate for 10 sec empty the tank, and repeat this step again.
Pour in the tank and agitate once every minute. Fixing time is usually 10 min. return the fixer to the bottle.
The film can now be washed. Washing is done using water to remove the processing chemicals, which will otherwise stain the film. Wet negatives (even when dry) are very sensitive and can easily be damaged by hairs, dust, scratches. They must therefore be handled by their edges. Washing of films can be done in normal light but inside the developing tank. A rubber horse is used to deliver water into the tank but it is advisable to use filters in case the water has grits or sand particles.
After washing the film should be thoroughly clean, they should be dried by hanging them to dry by the clips. Remaining liquids on the surface can be dried using squeegee tongs.
Once the film is dry, protect it as soon as possible from dust, and never fold it as these might cause scratches. A protective file is necessary at this stage for keeping or storing these films.

State the reagents required for preparing stop bath and fixer solution for film processing

Stop baths are usually weak solutions of acetic acid. Acetic acid is commonly available as pure glacial acetic acid or 28% acetic acid. Some stop baths contain potassium chrome alum as a hardener.

Fixer solution contain sodium thiosulfate (“hypo”) as the fixing agent, and sodium sulfite and sodium bisulfite as a preservative. Fixing baths also may also contain alum (potassium aluminum sulfate) as a hardener and boric acid as a buffer.

Describe the preparation of stop bath solution

Working solution is prepared by diluting the concentrate in distilled water while actively stirring.

To prepare stop bath working solution for film:

Dilute the concentrate of STOP bath to a ratio of 10 ml of concentrate to 490ml of water to obtain 500 ml of working solution or 20 ml of concentrate and 980 ml of water to get 1 litre of working solution).

To prepare stop bath working solution for photo papers:

Dilute the concentrate of STOP bath to a ratio of 10 ml of concentrate to 990ml of water to obtain 1 litre of working solution).

Using distilled water is strongly recommended to ensure best chemical capacity of all the processing chemicals.

Give four darkroom precautions

Limit access to the darkroom. Only authorized persons should be allowed to work in the room.
Practice good housekeeping. Keep the work area clean and uncluttered to prevent tripping over hazardous chemical bottles.
Separate the wet and dry areas.
Always segregate chemicals. Don’t store acids near reducer!
Use the least toxic chemicals available. Avoid cyanides, heavy metals, and developers containing pyrocatechol or pyrogallol when possible.
Do not store chemicals on the floor.
Do not eat, drink or smoke in the darkroom.
The darkroom should be well ventilated.
Wear appropriate protective equipment whenever possible, such as gloves, goggles, etc.
Always wash hands with soap and warm water after working with chemicals.
Know how to use emergency equipment prior to an actual emergency.
Always Add Acid to water, never water to acid. (Remember ‘AAA’)
Keep a spill kit in the darkroom.
Do not use paper towels or sawdust to clean up acid spills as this may cause a fire.
Pregnant women should not be exposed to powdered developer.
Store all chemicals in locations that will minimize the chance of breakage and splashing.
Label all containers.
Keep all containers and trays closed or covered when not in use to prevent the release of toxic gases.
Do not wash any chemicals down the sink (exceptions noted below).
All spent chemicals should be placed into an appropriate waste container. A container the same as the one the chemical was originally shipped in is best.

Identify differences between a single lens reflex (SLR) camera and twin lens reflex (TLR)

In the single-lens reflex camera, the photographer sees the scene through the camera single lens. Twin-lens reflex cameras use a pair of nearly identical lenses, one to form the image and one as a viewfinder.

Single lens cameras are prone to parallax error, in TLR, parallax errors are only encountered at closed distance.

Explain with practical details how Produce an enlargement print from a normal good quality 35mm black and white negative

Print enlargement is done using a special equipment called an enlarger. Enlarger has a condenser, which consist of a converging lens that concentrates light onto an even focused beam
The film is held below the condenser by its edges in a carrier that has its central area cut out in a rectangular i.e. the size of the negative. When an exposure is made, the lamp above the carrier projects the image down through the enlarging lens so that it appears enlarged on a sheet of light sensitive paper laid on the baseboard.

Define the following terms as used in photography.

(a).Fixing

The process of dissolving unused silver based salts or converting the remaining silver salts to be insensitive to any further exposure to light. This makes the image permanent and light resistant.

Development

Light is a form of energy and it can cause chemical changes in materials especially silver salts which are record as image. A layer of these light sensitive halides is coated over a flat surface and placed where light from the image fell. Light is exposed on it for a specific time. This will cause a negative image of the object to be created in black and white.

Such image created is however not permanently fixed on the film and it may be easily affected upon more exposure to light. For it to be permanently fixed, it have to further undergo additional steps in processing which will make the image resistant to any further exposure to light. This process is called development.

Outline the steps in processing of black and white film to a negative

In the first step of processing, the film is placed in developing agent that is actually a reducing agent. Given the chance, the reducing agent will convert all the silver ions into silver metal. Those grains that have latent-image sites will develop more rapidly. With the proper control of temperature, time and agitation, grains with latent images will become pure silver. The unexposed grains will remain as silver-halide crystals.
The next step is to complete the developing process by rinsing the film with water, or by using a “stop” bath that arrests the development process.
The unexposed silver-halide crystals are removed in what is called the fixing bath. The fixer dissolves only silver-halide crystals, leaving the silver metal behind.
In the final step, the film is washed with water to remove all the processing chemicals. The film strip is dried, and the individual exposures are cut into negatives.

State the precautions to be taken while preparing developer solution

When mixing powdered developers, use appropriate gloves, local exhaust ventilation, or approved toxic dust respirator.

Explain any four factors that can affect photographic film speed

Four variables are available to the photographer to obtain the desired effect: lighting, film speed, f-number (aperture size), and shutter speed (exposure time)

Discuss the requirement of a darkroom under each of the following

General requirements

The darkroom should be designed to provide the following conditions that are required for mammography:
- Appropriate lighting conditions for the handling of photosensitive film.
- Suitable storage for unexposed film in use with particular regard to radiation levels.
- Space for the film processor and accessories.
- Space for the storage of chemical solutions.
- Adequate facilities for the preparation of chemical solutions and for the cleaning of processor rollers (large sink and hose).
- Appropriate ventilation.
- Provision of silver recovery system.
- Adequate workspace for the loading of films, and a viewing area and workspace for sorting the films.
- Fire alarms and other warning signals should be audible inside the darkroom.

Note that these requirements still apply for daylight, or automatic feeding processors, in order to reduce image artefacts. Ventilation of the processor and handling of chemicals remains the same.

State and explain use of Darkroom Equipment

Various equipment are found in the dark room . this include:

The Enlarger

An enlarger is a special kind of projector used to create your photographic prints. By shining light through the negative, it transfers your image from the small negative and enlarges it onto your paper. It is the most important piece of equipment in the darkroom.

Safelight

A safelight converts your dark space into a red-lit darkroom. The reason you can have this red light on without ruining your paper is that nearly all darkroom papers are orthochromatic – which means they are partially blind to red light. Therefore they can be handled under dim red light without exposing them and ruining the paper.

Focus Finder

A Focus Finder is used to help you focus on the enlarger. It is important because if you don’t focus properly you will get blurry prints – just like when you are taking photos. When you look through it, it magnifies your image so you can see the actual grain of the negative you are printing. This helps you identify when the image is in sharp focus.

Darkroom Trays

Most darkrooms will have at least 3 trays set up. They are used to hold the developer, stop and fix when printing. There will also be a wash bath. You will be moving your paper from one tray to another through the developing process. They are designed to allow the chemicals to flow around the print while you gently agitate. These are simple, but vital when it comes to printing in the darkroom.

Print Tongs

Print tongs allow you to move your darkroom paper through the developer, stop and fix trays when processing your paper. They help reduce the risk of marks and blemishes as your prints can easily be damaged by handling when wet. A set of three tongs also means you can reduce the contamination between the different processing trays by assigning one set to each tray.

These are just the essential pieces of equipment you will find in a darkroom. Browse our Darkroom Equipment section to see the full range of kit we sell.

Explain how a film is exposed using single lens reflex (SLR) camera

The single-lens reflex (SLR) camera is one of the simplest cameras to use and offers an extreme flexibility for advanced users or beginners to photography. Single-lens reflex derives from a camera that uses a mirror system built in the camera that permits the user to see exactly what will be captured by the film or digital system. This is of great significance because most other camera systems (without digital backs) do not permit you to view exactly what will be captured. As such, these other systems may reveal a different image other than the one you attempted to capture if you don’t compensate correctly.

In the SLR camera system, a mirror sits behind the camera lens at a 45-degree angle with the film or digital input resting behind the mirror, blocked from light. The mirror bounces the image through the camera lens and out the viewfinder for the photographer to see the image. Once the shutter is released, that mirror flips up for the duration of time the shutter speed was set and flips down when completed. While the mirror is flipped up, the film behind it is exposed for the duration of time

Explain using a diagram how the parallax error is eliminated in a 35 mm SLR camera

Parallax error, also called “viewfinder error,” it is the difference between what you see in a camera’s viewfinder and the final picture. Typically, the picture image will be larger than the viewfinder image. There may be very little or no parallax error if the picture is previewed in the LCD screen. Single lens reflex (SLR) cameras also eliminate parallax error.

List steps involved in processing a black and white photographic film

In the first step of processing, the film is placed in developing agent that is actually a reducing agent. Given the chance, the reducing agent will convert all the silver ions into silver metal. Those grains that have latent-image sites will develop more rapidly. With the proper control of temperature, time and agitation, grains with latent images will become pure silver. The unexposed grains will remain as silver-halide crystals.
The next step is to complete the developing process by rinsing the film with water, or by using a “stop” bath that arrests the development process.
The unexposed silver-halide crystals are removed in what is called the fixing bath. The fixer dissolves only silver-halide crystals, leaving the silver metal behind.
In the final step, the film is washed with water to remove all the processing chemicals. The film strip is dried, and the individual exposures are cut into negatives.
When you are finished, you have a negative image of the original scene. It is a negative in the sense that it is darkest (has the highest density of opaque silver atoms) in the area that received the most light exposure. In places that received no light, the negative has no silver atoms and is clear. In order to make it a positive image that looks normal to the human eye, it must be printed onto another light-sensitive material (usually photographic paper).

Describe the loading of a 35mm film into SLR camera in order to obtain a maximum frame exposure

Step 1:

Locate the Rewind Knob, on the left side of the camera, and pull up until the back of the camera opens.

Step 2:

Cut a Leader for your film to load into the Take-Up Spool. The leader must be approximately 22mm to fit into spool.

Step 3:

Place the film into the left side of the camera. Push the Rewind Knob down to create a snug fit on the film after it is placed into the pocket.

Step 4:

Pull the leader of film over to the Take-Up Spool. Insert the narrow end of the film leader into the slot. Hold the spool steady with one hand and push the film deep inside until film is way inside spool or comes out the other side.

Step 5:

Make sure the teeth are properly placed on both sides of the film. Use the rewind knob to take in any slack in the film, tighten the film to the camera. Then close the back of the camera and use the film advance to wind the film.

Step 6:

Take 3 pictures. If the film has been loaded properly the rewind knob will turn ever time you crank the film advance lever. If not, make sure the slack has been taken out of the film by retightening the film to the camera. Make sure you take at least 2 pictures to clear out the exposed film and start with fresh film. Once you see the number 1 in the window, you are ready to take pictures.

Step 7:

Now its time to set your ISO Film Speed. To set film speed, gently lift up the ISO speed ring and turn it to your desired ISO speed shown in the window. (this should rotate the numbers on the INSIDE window on the ring)

Step 8:

To set Shutter Speed, rotate the shutter speed ring to desired shutter speed. The shutter controls the length of exposure, on this camera, the higher the number, the less the exposure time. (this should rotate the numbers on the OUTSIDE of the ring)

Step 9:

To set the aperture, turn the aperture ring to desired aperture. The larger the aperture number, the smaller the aperture opening will be and less the light will be transmitted to the film. (the dial closest to the camera)

Step 10:

This camera has a built in meter. When you press the shutter release button down about one third of the way, you will activate the meter. While the meter is activated, rotate the shutter speed dial or the aperture ring until only the green o LED is lit. when you see the red + LED light, this means your subject is too bright. To fix this, change to a higher shutter speed or aperture. When you see the red – LED light, this means your subject is too dark. Change to a lower shutter speed or aperture. The goal is to achieve the green o LED light for best results.

Step 11:

To set a timer, push down on the self-timer lever until it stops. When you are ready to take the photo, push the shutter release button completely to activate the timer. The photo will be taken in 10 seconds. (the length of the timer could depend on the make and model of the camera)

Step 12:

Once you have completed the roll of film, you must rewind it back into the canister. To rewind your film, press the film release button on the bottom of the camera. Fold out the film rewind crank and turn it in the direction of the arrow until you feel no more tension on the knob.

Step 13:

Pull up on the film rewind knob until the back cover of the camera opens. The film should be rolled back inside the film canister and it is now ready to be developed.

Identify differences between a single lens reflex (SLR) camera and twin lens reflex (TLR)

The SLR has one lens, and the TLR has two.
A 35mm SLR uses 35mm film, a TLR uses medium format film called 120 roll film.
SLRs typically have interchangeable lenses, TLR lenses are typically fixed.
SLRs typically have a viewfinder that you put up to your eye, TLRs have viewfinders at waist level.

Distinguish between projection printing and contact printing

Projection printing is the process of making positive prints by projecting the negative image onto photosensitive paper. The projected image may be enlarged, the same size as the negative image, or reduced in size. When the print images are larger than the negative images, the process is called enlarging.When the print images are smaller than the negative images, the process is called reducing. Because projection printing is usually used to make positive prints with images larger than the negative, projection printers are usually referred to as enlargers. The term enlarging generally refers to all forms of projection printing.

Contact printing is where a photographic print is made by placing a negative directly in contact with sensitized paper, with their emulsion surfaces facing, and exposing them to light. The defining characteristic of a contact print is that the resulting print is the same size as the original, rather than having been projected through an enlarger.

Projection printing differs from contact printing because the negative is separated from the paper and the image is projected by a lens onto the sensitized material.The negative is placed between an enclosed light source and a lens. The lens receives the light that passed through the negative and projects the image onto the paper. Changing the distance between the lens and the paper controls the size of the image. The image is focused on the paper by adjusting the distance between the negative and the lens. It is possible to enlarge or reduce the size of the projected image by changing and adjusting these distances.Enlarging is a very adaptable and versatile process because considerable image and exposure control can be used The main advantage of enlarging over contact printing is that large prints can be made, but there are several other important advantages. The advantages ofprojection printing areas follows:

Describe how suitability of a darkroom can be tested.

The suitability of a darkroom can be tested using the following methods

The Leak-Free Room

Turn off all the lights, including the safelight, and sit in your darkroom for a time. It may take up to 10 minutes, but eventually your eyes will adjust and problem light leaks will shine brightly. Now hold out one arm in front of you, with your palm out, like a traffic cop signaling “stop.” Can you see the outline of your hand? Plug any holes and use darkroom Blackout Cloth to curtain entrances.

b.Stray Enlarger Light

Turn on your enlarger lamp and look around the room. If the light reflects brightly off any shiny objects, mask them off. (Mask-off shiny things you bring into the room, too, like “canned air”.)

Now, inspect your safelight. Check to make sure that has the correct wattage bulb, and that your filters are not cracked. While you are at it, look at the electrical cable to make sure that it is also in good shape with no splits or exposed wire. Switch on your safelight and inspect housing. Make sure that no white light is leaking through. Check your filters for leaks also.

This test is comprised of two parts. In the first part of the test, you will determine the flash-point for your paper. The flash-point is the exposure time just before a visible gray tone is produced. When paper is “flashed,” it becomes more sensitive to any light that it is later exposed to. The flash-point will be used in the next part of the test, to determine how long a sheet of exposed paper can be subjected to the safelight before fogging.

In the second part of the test, you will mask off a fresh sheet of photo paper and “flash” expose it for the time determined in the first part of the test. This flash exposure will cause the paper to react to the safelight in the same way an exposed print does. After flashing the paper, you will expose it to the safelight in increments of several minutes (just like making a test strip under the enlarger). After processing, you will be able to see any effect that the safelight has had on your paper, and take corrective actions if necessary.

Explain the effects of not fixing the photographic film during film processing

The fixing bath contains a chemical (sodium or ammonium thiosulfate) that converts the silver halide into soluble, complex silver salts that dissolve in the fixer. During this process the film loses its original silver halide milkiness overlaying the image and becomes clear.

By fixation, the film or paper is made insensitive to further action by light. Without fixing, the remaining silver halide would darken and cause fogging of the image.

Name the function of the following parts of a camera:

Viewfinder

The viewfinder is one of the most important parts of a camera. It is a rectangular-shaped part at the back of your camera that lets you see and frame your subject. Some viewfinders are fully digital, which shows you various details like your shutter speed, aperture, and ISO before you take the shot.

Pentaprism

The pentaprism is a mirror placed at a 45-degree angle behind the camera lens. The mirror projects the light captured from the lens to the viewfinder. Before pentaprisms, photographers always had to look downwards when taking photos, which is not ideal for some subjects and would only allow you to take photos at hip-level. Pentaprisms got rid of this problem and now defines single-lens reflex or SLR cameras.

Focusing Screen

A camera’s Focusing Screen is the glass surface on which the camera’s mirror projects the image. The focusing screen helps in achieving various focus effects such as sharp and high-contrast shots to blurs and bokeh.

Condenser Lens

A condenser lens has two matching convex lenses. This part uses a simple method for correcting color fringing or aberration that is a common problem encountered when using traditional camera lenses.

Digital Sensor

The digital sensor of a camera is one of its most delicate parts. This sensor captures the light coming from the lens to create an image. Modern cameras use either a charged-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) imager for capturing images.

Shutter

The shutter is an opaque piece of metal or plastic that controls the amount of light that reaches the camera sensor. The length of which your shutter stays open will determine how your exposure will look like. You can activate this using the shutter release button and adjust it accordingly using your camera’s shutter speed setting.

Display

The camera display shows the user helpful information about the photos and the camera. Here you will see the different camera settings you can tweak to alter your exposure, ISO, shutter speed, and more. You can also access other menus using this display to change the settings on your camera. Most camera displays nowadays let you see how your image will appear before you press the shutter release button. This feature revolutionized digital cameras as it helps photographers in creating consistent shots.

Electronics

Your camera’s electronic components are divided into three separate categories: photo capture components, camera controller, and user interface components. The controller elements control all the electronic components of the camera. Its photo capture elements are responsible for the recording of images, while the user interface elements are responsible for letting the user interact with and control the camera

Reflex and Relay Mirror

The reflex mirror is in any SLR or DSLR camera. Unlike rangefinder cameras, the lens of a DSLR is not on the same axis as the lens, which is why this type of camera needs a mirror. The reflex mirror is a mirror positioned at a 45-degree angle to reflect light from the lens to the viewfinder, enabling you to see what the lens sees.

Aperture

Aperture is one of the three pillars of determining the exposure of your photographs. The aperture is the opening in your lens through which light passes through. This part has small, thin blades that shrink or expand depending on how much light you want in your exposure. It also determines the depth of field of your camera, which is a vital factor in how much background blur you want.

Zoom Elements

If you just bought your first ever camera, chances are you got a zoom lens with it. Zoom lenses allow you to shift between focal lengths, from wide to telephoto, depending on your lens’ focal range, by turning the lens rings.

Batteries

Lastly, the battery is one of the most important parts of the camera. Most of its components will not work if not powered by one. Having a long-lasting battery lets you shoot more photos and shoot for extended periods, allowing you to find the perfect shot.

Outline the process of setting up a projector

Remove the projector’s lens cover.
Connect the power cord to the projector’s power inlet.
Plug the power cord into an electrical outlet. The projector’s power light turns orange. This indicates that the projector is receiving power, but is not yet turned on (it is in standby mode).
Note: With Direct Power On turned on, the projector turns on as soon as you plug it in.
Press the power button on the projector or the remote control to turn on the projector. The projector beeps and the power light flashes green as the projector warms up. After about five seconds, the power light stops flashing and turns green.

Distinguish between diascopic and episcopic image production in projector

An episcope projects images from light reflected from the opaque surface of a document, book, etc. A diascope is for projecting transparent images formed on transparent media, usually a film, to become ‘transparencies’ for projection. A slide projector or movie film projector are examples of diascopes made for projecting film camera originated transparent images. However the term diascope usually means something larger. The transparent media will be at a more visually accessible size, to allow either a hand worked image, or page sized printed image, to be projected. The advantage of transparency projection, often by ‘overhead’ projection is that the transparency is in the path of light directed from it’s source toward the projector’s lens. To project comparable images from documents or books, an episcope would require much more light because all the light reflected from the surface of a document, book, etc, will be diffused. This means that a major proportion of the light illuminating the document does not enter the projection lens to contribute to projection of the the image. Episcopes were made with huge lighting setups and wide aperture lenses to counter this disadvantage. Not cheap to buy or to run, nor kind to any document. The epidiascope is a device which can operate either as a diascope or an epidiascope as per requirement.

(a) Describe keystone effect

The keystone effect is the apparent distortion of an image dimensions, such as making a square look like a trapezoid, the shape of an architectural keystone (hence the name of the feature) it is a problem caused by projecting it onto an angled surface or non-perpendicularly . The problem occurs when a screen projector does not have the depth of focus to show the lines in focus.

. This can result in the image looking like an architectural keystone. This is known as the keystone effect. The keystone effect can cause distorted images on a projector in a trapezoid shape and can also affect the angle of photographs if not corrected.

Describe how keystone effect can be eliminated from the projector

This problem can be resolved (Keystoning).by moving the projector towards the center of the projected screen, tilting the projector slightly or by controlling the projector via software or remote.

Outline the procedure for setting up an opaque projector

Opaque projectors work by shining a bright light onto an opaque object (like a photo or a sketch) and then using a combination of mirrors or prisms and a lens to focus an enlarged reflection onto a surface.

Here’s how to use an opaque projector:

You will need a small paper copy of your photograph, between 5 sq inches and 7 sq inches, depending on the size of your art projector’s opening. Place the image in the opening, turn on the machine and turn off the lights in the room. Make sure you have enough space to be able to pull the machine far back if you need to make a really big version. The projected image will appear on the wall, so you’ll need to position your canvas securely on the wall, and arrange the projector so that the enlarged image fits correctly within the size of the canvas. This might take some fiddling to get it just right. Double-check that the canvas is perfectly straight and flat against the wall, and that the projector rests perfectly flat upon its surface – otherwise the picture will turn out slightly distorted. You can see the illustration below for an idea of how it all work

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