Camera Types

• Point and Shoot
  • Pros – Quick, light, and easy to shoot; relatively cheap
  • Cons – Little control over how light is recorded
• DSLR (Digital Single Lens Reflex)
  • Pros – High quality, full control over light recording, versatile, optical viewfinder featuring a reflexive mirror and a pentaprism which allows light to pass through lens directly to eye.
  • Cons – Heavy, lots of moving parts, camera and lenses gets very expensive
• Bridge
  • Pros – Designed to split the difference between PnS and DSLR, full control, quality zoom lens
  • Cons – Digital viewfinder (basically a tiny TV screen) broadcasts from sensor but can be low quality and have color and frame rate issues, can’t change lens
• Mirrorless
  • Pros – The new kids on the block, they offer the convenience of a bridge camera with the ability to change lenses.  High quality with a very small footprint.
  • Cons – Not quite as good as DSLR quality and they don’t have all the functions, yet, but watch out for these in the future, they may provide the best value of all camera types
• Medium Format Camera
  • Pros – Incredibly high quality camera used to produce billboards and other huge image files.  Same functionality as a DSLR, so they are familiar to use.
  • Cons – Very, very costly.
• Smart Phone Camera
  • Pros – Easy to use, can use apps to extend functionality, very shareable.  Facilitates photography as a form of communication, eases delivery of photography.
  • Cons – Can’t change lenses, can be low image quality, less functionality.

Camera Functions

• Auto mode is simply trying to capture the correct amount of light, it doesn’t have any idea of the creative aspects of your shot.  Want to minimize using this mode, if possible.
• Program mode is advanced semi-auto mode.  Camera decides most things, but allows you to change a few aspects of your exposure triangle.  Avoid this as well.
• Preset modes are designed to give you the best image in a variety of situations.  Just more automatic modes, want to avoid these.
  • Sport or Action mode uses fast shutter speeds to freeze the action of a subject in motion.
  • Landscape mode tries to keep everything in focus with a small aperture.
  • Macro mode lets us get close to the subject.
  • Portrait mode is combination of settings designed for shooting portraits, background is out of focus but subject is sharp.
• A mode or aperture-priority mode gives control over camera aperture while camera controls level of brightness.
• S mode or shutter-priority gives control over shutter speed (time-value), while camera controls brightness.
• M mode or manual gives full control of camera settings to the photographer, this is where you want to be.

Lenses

• Normal / Standard Lens
• Wide Angle Lens
• Telephoto Lens
• Zoom Lens
• Super Wide Angle Lens
• Fisheye  Lens
• Macro Lens
• Components of Lenses
  • Front Lens Element
    • first piece of glass in the series of special shaped glass that makes up the lens.  Front element has coating to protect the lens.
  • Manual focus ring
    • allows you to focus the lens to your specified distance.
    • not necessary to use manual focus with manual settings
  • Distance Scale
    • tells how far away the camera is focusing, want subject to be this distance away
  • Zoom ring
    • zoom in to scene
  • Lens Mount
    • very delicate and containing electrical components, take care of this
  • Auto / Manual Focus Switch
    • can switch lens between auto or manual focus
    • adjusts the data sent from lens to camera
  • Bayonet
    • the rings that thread for the lens hood and lens adapters
  • Thread
    • used to attach filters to the lens

Angle of View – Human Vision

Humans have a view of about 130-degrees wide, but only about 50-degrees is actual in focus at any time.  The 40-degrees on each side is slightly out of focus, this is called periphery and is dominated by either eye.  Key difference between our vision and lenses is they have no periphery, everything in the frame is in the same focus.

Most of the data we see is in the periphery, with our focus being a very small square where our eyes can cross and focus correctly.

Standard / Normal Lens

These roughly capture the same angle of view as human vision, which is roughly 50-degrees wide.  In general, these will be 50mm lens.  Nifty fifty’s (a popular lens type) roughly match human vision. It is important to understand how small a portion of the field of view is captured by these lenses.

Wide Angle Lens

These have angles of view between 50-degrees up to 80-degrees and come in focal lengths of 14mm to 50mm.  Millimeter focal lengths refer to the distance between the piece of glass that focuses the image and the sensor.  In 24mm lens, focus glass is 24mm from sensor.  The further away, the further the lens can see.

Telephoto Lens

Any lens with focal length of 50mm.  Telephotos have a narrow field of view between 50 degrees and 2.5 degrees.  They are great for getting close to subject without actually moving closer, but narrows in on the subject and distorts closeness.  Every lens shows us a different view of the world, important to understand how your lens constrains your field of view to compose your shots correctly.

Zoom Lens

Lenses with variable focal lengths.  Can have wide zoom lenses, telephoto zoom lenses, and crossover types (18mm – 56mm).  With zoom lenses, we get a variety of different ways to view the world.  They are a large advantage for versatility and can be lower priced than the equivalent amount of prime lenses.  Prime lenses have fixed focal lengths (can’t zoom).

Advantages of Prime Lenses:

• Are often sharper in focus than zoom lenses.
• Also slightly higher quality at the lower price ranges.
• Prime lenses often offer large apertures.
• Smaller and lighter than zoom lenses

Super wide angle lenses

Lenses that go wider than a 14mm lens.  Our human vision is approximated by a 10mm lens.

Fisheye Lens

Have a 180-degree field of view, similar to looking from one shoulder to the other.  Curves all straight lines with a hemishperical view, especially around the edges of the picture.

Macro Lens

Shows tiny objects.  They are usually prime lenses with a high millimeter distance.  Most lenses dont allow camera to get physically close to the subject and still focus, while macro lenses can correct this error.

Conclusion

Depending on which lens you use, will want to change how your compose and envision every shot.

 

Light and Exposure

All objects reflect light, allowing us to see them.  Even very dark objects reflect some measure of light (The only object that doesn’t reflect light is a black hole (0% luminosity)).  Light is emitted by the sun and bounces off everything around us, then enters our eyes, allowing us to see the world around us.  The only difference is the camera wants to both measure and record the light.

Light is similar to water in that there is a constant stream of it and we can control how that stream enters the camera (or our eyes).  Our eyes and brain are both involved in shaping the light that we register in our human experience.  Physiologically, the pupil in our eye can become larger or smaller to let in more or less light, this is analogous to the aperture of the camera.  When in a dark room, our pupil opens up (gradually, as your eyes and brain adjust to the change in light) and closes down in bright lights.

Film and camera sensors work similarly in that once exposed to light, they start to capture the light that they are given until the light source is removed.  If they keep capturing light, then the film or sensor will become over exposed.  If the light is removed too quickly, not enough exposure occurs and the image is dark and unformed.  Over time, two methods were developed to determine the amount of light that is allowed to expose the recording medium; aperture and shutter.

Exposure

Refers to getting the proper amount of light captured to acquire the image you are shooting for.

• Over Exposure – Too much light, distorts color, blows out highlights and pushes them to white, removing hightight detail.  Any time you have pure white in your image, any detail is lost.  Also causes issues for printing and doesn’t look consistent across screens.  Works same way for shadows, in inverse.  In print, if you have highlights that go to pure white, they lose detail with the paper itself, so you can’t tell the difference between the paper and the image.
• Under Exposure – Too little light, distorts color, blows out shadows, pushing them too black and removing any detail in the shadows.
• Correct Exposure – Proper amount of light and scene is recorded in the way it is or the way you desire.

Motion and Depth

Motion in an image is controlled with shutter speed.

Focal Plane Shutter

Sits just in front of the sensor, opens to let light in.  Used to set shutter speed mechanically, then use shutter button to open and close in the duration of time chosen.  When shutter button is pressed, the shutter moves out of the way, revealing the sensor to allow light to pass through the camera and be recorded.  The shutter is located between the mirror and the sensor.

Shutter Speeds

The shutter speed controls the duration of time that light is entering the camera and exposing sensor.  Length of time is known as the shutter speed.  Shutter speed are measured in seconds or fraction of seconds.

Why Change Shutter Speeds

• Control motion and how it is captured with shutter speeds
  • fast shutter speeds stop the motion and create a still image
  • slow shutter speeds introduce motion blur
  • depends on how fast subject is moving, if shutter is faster then movement, will get still image.
• Control exposure with shutter speeds

What to Watch For

• Camera shake can be introduced if movement to camera is added during sensor exposure.  Handheld, don’t want to go faster than 1/80 of a second.  Can us vibration reduction to help with this.

Aperture

Aperture is a secondary mechanism for controlling light.  It controls how much light is allowed to hit sensor.

Shutter controls how long light get into camera, aperture controls how much light gets in.

F Stops

Apertures are expressed as F Stops or F Numbers.  Each lens will have a range of standard aperture sizes.

Larger the number, the smaller the aperture

Aperture will affect your depth of field, or how much of the scene is focused from front to back.   Portraits use shallow depth of fields, where subject is focused but background is not.  Uses a F/2.8.  Landscapes use F/22 to show everything in focus, giving a deep or wide depth of field.

Depth of Field

A measure of the focal subject compared to the blurred background.  The depth surrounds the object that you are focusing on.  It you are focusing on a subject further in the background, can create a blur for the object in front of the focal subject.

Conclusion

Can use shutter speed and aperture to control the motion of our subject and how much of our subject and background is in focus.  Use these to control the viewer to lead them to focus on exactly what you want them to and get the feeling that you want to convey about the subject.

 

Composition

Composition refers to the placement of elements within your scene.  It determines the difference between a good and a bad picture.  We learn about composition to help communicate the subject and the scene clearly to the viewer.

It’s important because the viewer only gets the small rectangle to try to understand what the photographer is conveying.  Everything that led the photographer to take that picture, the experience, the feelings, are all irrelevant as the viewer only understands whats inside the photo.  Composition, therefore, attempts to fill in the gaps and give the viewer the actual experience you had when being there.  It helps your picture tell its story clearly and effectively.

What you choose to include in the frame, and what you choose to exclude, has a very profound impact on exactly what you are communicating to the viewer.

The first step to composition is understanding how cropped your view is through the viewfinder.  You are getting a very small portion of the scene in front of you, and you need to convey the entire scene within the small rectangle you are given.  Because of this, take shots of the same scene from different angles to actually see the entire scene.  Make sure you are aware of every element in the shot, and be sure that you are choosing for that to be there.

Tip – Trace your eye around the frame of the viewfinder to inspect the border of your photo to make sure you are including what you want, and excluding what you don’t want.

Exploring the Subject / Scene

Only taking one shot of one scene and moving on doesn’t do justice to the scene or your audience.  As a photographer, it is your duty to search out the most effective delivery vector for your photographic idea and to keep shooting until you’ve found the image that you prefer.  Move around, try higher or lower perspectives, get closer or further, go from vertical (portrait) to landscape (horizontal) but explore your subject to determine the most effective shot.

In the beginning, you will take a huge amount of photos to get the shot you want.  As you become more experienced, you’ll be able to see instantly if a shot doesn’t work, lessening the number of shots and increasing efficiency.

Even bad shots help you analyse your subjects to determine what works and what doesn’t

Rule of Thirds

Break your image into a 3 x 3 grid and place important compositional elements on the lines themselves or at intersections of the lines.  This creates a sense of tension and energy and gives the subjects in your image a logical placement.

Balance

Every element in the image carries compositional weight.  Visual weight can be offered by color, shading, texture, etc, there is no one rule.  There are a few general concepts:

• Darker has more weight than lighter
• Closer has more weight than further
• In focus has more weight than soft or out of focus elements

Balance allows the viewer to move through the image without stopping on any single element.  Balance blends the elements together to allow for a greater impact from the entire image, not just a single element.

Point of View

Unless we are conscious of it, we can take every image from our own height and from our own perspective.  Must always try out different POV’s to find a better way to engage the subject.   Shooting people from below indicates power, and in vice-versa, viewer is given position of power.  Also consider the level that your subject is at, getting on that level will create sense of engagement with subject.  This is important for kids, best to be on their eye level.

Simplicity

We want our photography to communicate clearly and effectively, and this is directly related to simplicity of the image.  Can accomplish simplicity in a variety of ways:

• cropping
• focusing
• use tonal effects to highlight some things independent of others

Composition Extended

These techniques are intended to augment the existing composotional elements of subject, balance, point of view, and simplicity.  They are also used when you aren’t satisfied with the composition you are attempting to capture.  Often times, when you just can’t get the subject captured the way you’d like, its better to step back and look at the geometry which makes up the composition and attempt to best capture that.  Also works if you can’t find anything interesting in the field 🙂

Lines

One of the most interesting forms to work with as they lend strength to your composition.   Lines can lead viewer through the compositional frame to help tie elements together.  By looking simply at lines instead of a subject or an actual object to shoot, you can come up with some interesting ideas.

Lines can be implied to a repeating series of elements.  They can also be created by shadows, tones, or even light itself.  Doesn’t necessarily need to be a straight line.

Shapes

Shapes can come in the form of literal shapes, combined shapes, or implied shapes.  Remember, they don’t have to be perfect shapes to still provide the same function.

Repetition

Can come from shapes, lines, or any form really, repetition provides order and helps make sense of the visual scene.  Can find repetition naturally, or can utilize camera positioning to find repetition in your scene.

Rule of Threes

When composing images, three subjects creates a sense of repetition or pattern.

Symmetry

One of the easiest ways to achieve balance is to find symmetry.  It creates a natural logic and order, giving the eye natural instructions on how to navigate the image.  Reflections and shadows are great for capturing symmetry.

Entry and Exit

Compositional techniques are used to create order for the viewer to experience the scene.  This idea can be applied to shapes, lines, or any element that helps instruct the viewer through the scene.  Doesn’t always have to be from foreground to background, can bring viewer in from one side and exit the scene on the other side of the image.  Common entry / exit elements are roads, railroads, etc.

Framing

In the largest sense, framing is simply composing the element within the frame of the camera.  Specifically for advanced composition, frames within images are a great way to further direct the viewer to what is important.  Frames consist of strong forms around the subjects that draw the eye to the subject.

Visual Consistency

Visual Consistency refers to having structure to the composition.  It is an element in the composition that links everything together to help the viewer understand the relationships.  Simplicity is closely related to visual consistency.

 

Understanding Light

Using a light meter, you can reduce the amount of over/under exposure in your photography.  The camera has it’s own light meter which measures the light that will hit the sensor.  Light meters work by assuming that the subject is reflecting 18% of the light and it gives you the settings to gather 18% of the light from what you are pointing out.

Most subjects only reflect about 18% of the light from the sun, the rest is absorbed by the subject and becomes heat.

For most scenes in the world, 18% is a good bet.  However, we sometimes need to let in or keep out a bit more light.

Stops

Light is measured by our camera in stops of light.  A stop refers to a measurement of a volume of light.  It is a doubling or halving of the amount of light in your scene.

Double light increased by 1 stop, decrease by half decreases by 1 stop.

The light meter is usually a scale from -2 to +2 which measures the light that will hit the sensor.  When at 0, the camera is receiving 18% light, which is usually a good exposure.  +1 indicates that the camera is receiving double the light that you want for the exposure.  +2 indicates 4 times the amount of light you need. +3 is 8 times more light. -1 is half the light you need. -2 is 1/4 of the light.

In automatic modes, the camera attempts to adjust the exposure triangle to always get 18% of light.

The light meter isn’t perfect because some subjects don’t reflect the same amount of light.  This problem is amplified by dark or light subjects, meter will overexpose dark scene and underexpose light scene.  White subjects reflect more light than dark subjects, which can affect the way the light meter calculates the settings for the scene.  You can use exposure compensation to correct for this (only applicable to auto or semi-auto modes).

Exposure compensation moves the light meter off of 0, allowing us to purposely over or under expose the image.

Manual Mode

When shooting in manual mode, you have full control of your exposure triangle.  Must understand some critical concepts to be successful in manual mode:

• Light Stops
• Common Shutter Speeds
• 1/4   1/8   1/15   1/30   1/60   1/125   1/250   1/500   1/1000   1/2000   1/4000   1/8000
  • <-  Faster Shutter Speed     –     Slower Shutter Speed ->
  • The relationship between 1/250 and 1/500 is 1/2, so moving from left to right decreases creases the light entering the camera by 1 stop.
  • From 1/500 to 1/250 increases the light entering the camera by 1 stop
  • Speeds between common shutter speeds are known as 1/3 and 2/3 stops, respectively
• Common Apertures
  • F/1   F/1.4   F/2   F/2.8   F/4   F5.6   F/8   F/11   F/16   F/22   F/32
    • <- Larger Aperture Size   –   Smaller Aperture Size ->
  • Apertures sizes have a physical ratio of 2:1 between them
    • From F/2 to F/2.8, you are decreasing light by 1 stop, physically halving the size of the aperture
    • From F/8 to F/5.6, you are increasing light by 1 stop, physically doubling the size of the aperture

Process of Shooting in Manual Mode

1. Set your exposure setting as determined by the scene you are shooting
   1. if landscape or portrait (scene without much movement), you will want to control aperture artistically, so use the shutter speed to control the light entering the scene
   2. if a moving scene, you want to use shutter speed to control motion, so try to use aperture to control the light as much as possible
2. Read the light meter to determine your current exposure level
3. Manually adjust the shutter speed and aperture to get the correct exposure of your scene
4. Shoot Away!

ISO

When you want a certain shutter speed and aperture for the artistic decision you have made, use ISO to increase the light entering the camera. ISO turns up the sensitivity on the light-sensitive sensor to create the same picture with less light.

• Common ISO’s
  • 100   200   400   800   1600   3200   6400
    • <-  More Sensitive   –  Less Sensitive ->
  • default is usually 100
  • as you move from 200 to 400, you are increasing the light 1 stop, doubling sensor sensitivity
  • as you move from 3200 to 1600, you are decreasing the light 1 stop, making sensor 1/2 as sensitive

ISO does have a price, as every time you increase ISO you increase grain / noise.  This is distortion introduced into your image, so have to be careful about image noise.  This higher the ISO, the worse the image will look.  ISO 100 is the cleanest image your camera can produce, it is the highest quality image you can get.  Only use ISO if you can’t get enough light, as a bit of noise is better than no picture at all.  Try to minimize the use of ISO in your photography.  That said, it is normal to use the low ISO’s (200 – 400) to increase a few stops, but try not to go beyond there.

 

The Color of Light

The goal of understanding color temperature is to capture the scene as you see it.

What is White Balance

We encounter many different lighting conditions during the day, including:

• Fluorescent
• Tungsten
• Daylight
• Cloudy
• Shade

All these different lighting situations have their own color temperatures.  As humans, we don’t see this because our brain and eyes work together to correct the image so we see things properly.  Camera lenses lack this processing, but they do offer Auto White Balance (AWB) to try to help.

Color Temperature

Color temperature refers to the amount of heat generated by a light source.  The warmer the light, the more blue the light appears (temperatures are measured in Kelvin (K)).  The cooler the light source, the warmer the light it produces.  For example, a candle flame is 1,000 K, but produces a warm-feeling light.  Comparatively, the cloudy sky is 6,500 Kelvin.

Even though physics clearly states that red light sources are cooler than blue, in photography we refer to blue as a cool tone and orange / red as warm tones.  Then, some light sources are balanced, or neutral tones, and provide little-to-no color casting.  Color temperatures create a wash over our image in a certain color cast (where all tones are not represented naturally as they existed in the scene), ad understanding of white balance will help you control these color casts.  At times, color casts can be used artistically to achieve a particular feeling, but you want to be sure that you are the one controlling the color, not the camera lens.

White Light (Neutral)

Daylight is a neutral tone in the 4,800K to 6,500K range that doesn’t provide any color tone (white light).  For this reason, daylight / white light is also the term used for any lighting situation that doesn’t create a color cast.

Fluorescent Light

Overhead tube lighting in office spaces, used for industrial purposes.  Range is from 4,000K to 7,000K, but most common is around 7,000K and produces a green-blue color cast.

Candle Light

Very orange / red light that can be found in range from 1,800K – 1,900K.

Morning / Evening Sunlight

Found at 2500K, this light provides strong orange to yellow color cast.  Often times, photos taken with this light are taken to utilize the color casting.

Tungsten Lighting

Found from 3000K to 4000K, this provides a very strong yellow color cast.

Cold Colors

From 6500K and up, light provides a very strong blue color casting.

Auto White Balance (AWB)

Camera constantly adjusts temperature to reduce any color casting.  This is a very proprietary process and each manufacturer does it differently, but in effect, the camera locates the brightest element in the scene, assumes this to be white, then corrects this element for any color cast, thus changing the color temperature across the entire image.

The problem is that the camera doesn’t know for sure which objects are to by white, so it can interpret something incorrectly and provide incorrect color cast settings.  The camera can pick the wrong object to de-cast, thus coloring the entire image.

AWB works well most of the time, especially if there is a clear, strong white element in the scene.  If not, the scene can be reproduced incorrectly.  For this reason, we have white balance presets. These presets help adjust the color temperature in situations where the AWB would have trouble reproducing the image correctly.  For instance, shade is hard for the camera to understand and AWB would create a cool color cast, where the shade preset will give a more natural representation.

Manual / Custom White Balance

Two methods to manually white balance.  First is to manual white balance in camera.  This entails using a balance card (white / grey card) to capture the lighting conditions, then letting the camera analyse the the grey card photo to determine any color cast.  You can then use these setting for the rest of the shoot.  Do this whenever the lighting temperature changes. Grey cards can also be used to create more accurate exposures.

The 2nd method to manually white balance is to fix the white balance in post production using your image processor (Photoshop or Lightroom).  This only applies to photography in the camera RAW format, which allows you to adjust the white balance of the photo after the image is taken.  Have the subject hold the grey card, then take the photo and continue with your shoot.  In post production, you can use the grey card shot to get your white balance settings, then you can export those setting for all the shots in the scene.

Focusing

It is important to note that Auto Focus doesn’t focus on a subject (the camera has no idea of what the subject is compared to the background), but rather a distance from the camera.

For the most part, we will use Auto Focus to assist with our focusing.  Auto Focus generally super-imposes a point selection grid inside the viewfinder showing what the camera has chosen to focus upon.  It is important to note that Auto Focus doesn’t focus on a subject (the camera has no idea of what the subject is compared to the background), but rather a distance from the camera, and everything of a similar relative distance will be in focus.  This is a complex process because there are many different elements for the camera to focus upon and the camera has no idea of what you are trying to do with the photo, so we can do a lot to help auto focus.

The camera finds the easiest element to focus upon, so we need to manually change this to give us control over what is in focus.  To do this, the camera has focal point selection, which allow us to tell the camera exactly the focal point that we want used by the autofocus.  This is performed in the focal point selection menu (different across camera makes).  This is only a feature of auto focus single point in my camera.  If not using single point autofocus,  I’ll give you my solution for choosing your focus point with auto focus.

After composing the shot in your viewfinder, you can choose the exact focus by switching to live view (LCD Viewfinder), then zooming into the scene with the zoom buttons on the camera.  Zoom in a few times, then move the focus box to the subject (focus on the eyes if it is a person) and press the shutter release half-way.  This will focus the sensor on the new focal point you have just set, so you can then zoom back out and take the picture (must stay in live mode for your auto focus settings to remain.)

Other technique is to set camera to focus upon the center of the image.  Then you turn the camera to center upon whichever subject you’d like to be perfectly in focus.  Focus on this subject by pressing the shutter release half-way down but keep you finger in this position (half way down).  This locks the focus, so you can then return the camera to the location for your composition, and now press the other half-way to take the shot with the set auto focus.  Can use the shutter release timer to control this in a very effective way.  Can also use AE-Lock / AF-Lock to lock the focal point before recomposition of the image.

Focusing Modes

Servo Mode

These are tracking modes, designed to help the camera track moving subjects.  Moving subjects can change focal distances between the time that the camera focuses and the picture is taken, so the camera has to adjust for this.  Servo mode or motion tracking mode alows the camera to continually refocus once the focus is established, so the subject is never lost. AI Servo mode is a newer technology that continuously focuses the camera on a moving subject, but locks the focus if that subject stops moving (higher accuracy).

Image Size

Image size and image quality are inversely proportional, knowing the proper sizes for the proper uses is critical to getting fast download speeds and great visual presentations.

Pixel

Pixel is short for picture element.  Each pixel is only one color and is a square in a grid, when placed in relation to others they create a continuous image.  Pixels are the building blocks of images.

Resolution

How the picture resolves to our eye.  High Resolution looks clear with smooth lines and crisp edges and we cannot identify pixels, uses millions of pixels.  Low Res is low quality can we can see breaks in the tone and pixels, uses less pixels.

HiGH Res v. LoW Res

• High Res – Smooth lines, crisp edges, high pixel density with very small pixels
• Low Res – Broken lines and soft edges, low pixel density with large pixels

To calculate resolution, take width by height then multiply them, giving your the Mega Pixel count.  For Instance, camera that captures 5616 X 3744 = 21,000,000 or is a 21 Mega Pixel image.

Print Res V. Screen Res

Print Resolution is completely separate from On Screen viewing.  High quality prints need to be 300 pixels per inch.  On Screen images can be much lower resolution, around 96 pixels per inch.  The old standard for on Screen was 72 ppi, but has moved to 96 ppi for more quality.  To calculate the print size, take the width and height and divide each by the expected PPI (300); this gives you the largest dimensions you can achieve with a high image quality.  The same image can by over 3X larger on screen when set at 96 PPI.  Or, conversely, a lower quality image (10% of the total pixel count) can be placed on a screen at the same size with the same optical quality .

File Formats

JPEG

Standard file format for photographic images across the world.  Anything that can show a picture can show a JPEG, it is a universal file format.  Small file size and jpegs are processed in the camera (the color saturation, contrast, sharpmess, and noise reduction are set by the camera) and they are a Lossy compression format (quality is degraded and info is discarded to make the file smaller).

Every time your save the image again, the file continuously tries to make itself smaller and quality is reduced each time.  JPEG’s feature a Reduced Dynamic Range which has poor highlight / shadow recovery (this is the info that is discarded).  Limited color space so there isn’t enough color information to have smooth transitions between colors, so you have color banding.

RAW

Camera RAW captures a much greater Dynamic Range.  It actually captures more than we see with our eye, and when we play with the highlights / shadows, we can bring out tones and objects that were masked by the shadows / highlights.  RAW’s also have a larger color space in that the colors won’t band, there will be smooth transitions.  With RAW’s, you can make dramatic adjustments without losing image quality.  They are also uncompressed and record the scene as exposed without contrast, sharpness, or any other camera adjustments.  A big downside is that RAW is a proprietary file format and each company has a specialized RAW file, so you will need specialized software to open and edit and use RAWs.

The beauty of RAW files is that you have full control of your photo and have lots of possibilities during post-production.  All edits are live (non-destructive) and any changes can be reverted at any time.  These are very large file sizes, so you will need a large storage option.

Straight from the camera, the JPEG’s look superior to RAW’s because they have been edited, but RAW’s will look better once edited.  In fact, RAW’s are useless until they have been edited and exported to a more standardized file format.