digital photography i

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Peter Liu Photography

Digital Photography I

The Basics

Peter LiuPhotographykaiscapes.com

http://kaiscapes.com/



Photography

From two Greek words meaning “drawing with light”: φως phos ("light") γραφις graphis ("stylus", "paintbrush")

Merriam-Webster:“The art or process of producing images on a sensitized surface (as a film) by the action of radiant energy and especially light.”


Photography

“The art of capturing light as it falls on a subject or scene, and

rendering it so that your viewer is moved by the result.”


Capturing Light

Hard Light – high contrast, well-defined shadows


Capturing Light

Soft Light – diffused, rich colors


Capturing Light

Overhead Light – harsh shadows


Capturing Light

Front Light – flat, lacks dimension


Capturing Light

Side Light – evokes mood, accentuates shapes


Capturing Light

Back Light – may need to fill, makes silhouettes


Capturing Light

Overcast Light – low contrast, muted shadows, good for detail


Characteristics Of LightQuality

The smaller the light source, the harder the light appears The larger the light source, the softer the light appears

Direction Determines where shadows fall

Contrast Difference between the lightest and darkest tones of the subject or image

SourceAmbient – daylight, tungsten, flourescent, firelightArtificial – flash, tungsten

IntensityReflectance

Reflectivity of the subject Intensity of the light source Angle of view Distance of light source

Fall-off Increase distance, decrease light level (Inverse Square Law)


Characteristics Of LightColor Mixture of primary colors: Red, Green and Blue – varies

according to source “Warm” – predominantly red “Cool” – predominantly blue Expressed in Kelvin (K):

Incandescent ~ 3000K Fluorescent ~ 4100K Flash ~ 5400K Daylight

Direct Sunlight ~ 5200K Cloudy ~ 6000K Shade ~ 8000K

Referred to as “White Balance” in digital photography.

White Balance

4100K (Fluorescent)

3000K (Incandescent)

5200K (Sunlight)

8000K (Shade)

5400K (Flash)

6000K (Cloudy)


Why Are You Telling Us All This??

Because good photography depends on being able to execute two things well:

ExposureComposition


ExposureA combination of three factors sometimes known as the “Photographic Triangle”:Shutter SpeedApertureISO

Or…

how quickly light is being captured through how big an opening onto how sensitive a surface


ShutterA camera’s shutter covers the hole through which light enters to expose the sensor or film.

The shutter release button causes the shutter to open for a certain amount of time, then close again.

Image source: www.howstuffworks.com

Image source: VisibleDust

http://www.howstuffworks.com/



http://www.visibledust.com/


Shutter Speed – Fast

1/1600 sec., stops action


Shutter Speed – SlowSilky, cool, edgy effects

1 sec.

3 sec.

1/3 sec.


Shutter Speeds Open too long, photos are washed out (overexposed) Not long enough, photos are too dark (underexposed) Expressed in seconds: 1/8000, 1/4000, 1/2000 1/1000,

1/500, 1/250, 1/60, 1/30, 1/15, 1/8, 1/4, 1/2, 1 second, 2 seconds, etc.

Each setting is half or double the speed of its neighbor. As the amount of available light decreases by half, the

shutter speed needs to slow by double. As the amount of available light increases, the shutter

speed needs to increase


ApertureThe opening through which light enters the camera.

Sometimes called an iris because it imitates the opening in the human eye.

Image source: www.howstuffworks.com


Aperture The size of the opening is expressed as an f-stop

number: 1.4 2.0 2.8 4 5.6 8 11 16 22 Each number represents an opening size that is half or

double its neighbor The larger the number, the smaller the opening For all the science types: the f-stop is actually a ratio

between the diameter of the aperture in the lens and the focal length of the lens:e.g. f/2 on a 50mm lens says the aperture is 25mm. 50/25 = 2.(Source: “A Tedious Explanation of the f/stop” by Matthew Cole)

For the rest of us: the size of the opening controls the depth of field in the photograph.

http://www.uscoles.com/fstop.htm

http://www.uscoles.com/fstop.htm


Aperture And Depth Of Fieldf/5.6

Shallow depth of field

f/22Deep depth of field


Aperture And Depth Of Field Caused by refraction of the light hitting the edge

of the opening Rays scatter and overlap instead of going

straight on its way to the sensor or film The camera “sees” multiple images, resulting in

blur. The smaller the opening, the less surface

available to scatter the light, resulting in less blur.

Bottom line: the aperture is used to control how much of the scene is in focus.


Aperture And Shutter SpeedThe following reciprocals will yield the same exposure:

What changes is how much is sharp and in focus.

f/2.8 1/500 sec.f/4 1/250 sec.f/5.6 1/125 sec.f/8 1/60 sec.f/11 1/30 sec.f/16 1/15 sec.f/22 1/8 sec.


The Light Meter A device that assesses a scene and figures out

the correct exposure Modern cameras have them built-in External handheld models also available Engaged when shutter is pressed halfway Matrix/Evaluative, Center-weighted, Spot

metering Looks for “18% Grey” or “Middle Grey” Easily fooled!


Tricky Metering Situations


Exposure Compensation

Used when the light meter is unable to evaluate the exposure as desired, or when correcting by whole stops is too much

Usually +/- 2 EV (Exposure Value) in steps of 0.3 EV

Available on most cameras


ISO Sensitivity of the sensor or film to light Represented by a number assigned by the

International Standards Organization (hence, ISO) – 100, 200, 400, 800, etc.

Again, each number represents double or half the sensitivity of its neighbor (Ain’t it wonderful!)

The higher the number, the more sensitive to light

Digital photography is cool because you can change the ISO from shot to shot!


Higher ISO = More Noise!

ISO 3200


So…Exposure depends on:

Shutter Speed – how fastAperture – how muchISO – how sensitive

And color is a function of:White Balance – how hot


And…

Which camera you choose is a function of how much you want control those factors!


CamerasTwo popular types of cameras on the

market for the consumer

Point-and-shootSLR (Single-lens Reflex)


Cameras

Point-and-shoot Viewfinder separate from

lens Small and compact Fixed lens Shutter delay Usually fully automatic

(some exceptions, like Olympus C-series)

SLR (Single-lens Reflex) Based on 35mm design Actual image seen in viewfinder Interchangeable lenses (more flexible composition) Ability to use filters More advanced metering and shutter system Little to no shutter delay Automatic, Program (“Scene”), Shutter Priority,

Aperture Priority and Manual modes Flash hot shoe Pro models may not have pop-up flash or Program

(“scene”) modes


Point-and-shoot Anatomy

Viewfinder separate from lens (better to use LCD on digital) Actual image (as exposed) is not quite the same as in the viewfinder Much simpler design than SLRs.

Light Path

Lens

Camera Body

Viewfinder(front)

Shutter

Sensor or Film

Viewfinder

Focal Length

LCD Screen(Digital)


SLR Anatomy

Through-the-lens (TTL) viewing (works like a periscope) Actual image (as exposed) is shown in the viewfinder Mirror flips up when the shutter release is pressed, exposing the sensor (and blacking out the viewfinder) “Reflex” comes from the use of the mirrors in the viewfinder system.

Light Path

Lens

Camera Body

Focusing Screen

Mirror (Pentaprism)

Mirror (flips up)

Shutter

Sensor or Film

Viewfinder

Focal Length

LCD Screen(Digital)


Advantages Of Digital Instant gratification (big fun factor) – see your images right away No film cost – shoot as many as you want, erase and shoot again

(heck, it’s just pixels!) Convenience – print, email, web, slide shows; no waiting around for

the photos to come back from the store Easier to make copies – no need to send (or lose) originals Easier to manipulate – no scanning required (you did that when you

pressed the shutter) No need to spend hours in the darkroom Black-and-white – just shades of grey colors No worries about film fading over time; digital images last for as

long as your storage media doesn’t die on you Less storage space – no physical shelves to keep stacking Metadata information available for indexing and cataloging.


Disadvantages Of Digital Image quality

As good or better than 35mm in the right hands, but cannot compete with medium or large format film (yet)

1.5x “cropping factor” or “focal length multiplier” in SLRs due to smaller sensor Exposure much more critical – 1/3 stop subtle in Velvia, but blatant in digital Blown highlights – no information means no information; film is better at rendering overexposed

areas more naturally Great shadow detail, but clipped highlights -- traded highlight detail for lower noise; most likely

need to underexpose and correct in post Skilled user needed to extract the image quality equivalent to that of good film

Very different workflow – requires skill with computers and software, knowledge of color management and printing, web, email, etc.

You are the photo lab – you’ve traded darkroom chemicals for a digital darkroom Easy to lose images – memory cards can become corrupted in-camera; photos are

scattered all over your computer; hard drives die Slow – camera is locked up once the buffer is filled until the images are completely

written to the card Shutter delay (point-and-shoot) Digicams are much more expensive than film cameras and become obsolete sooner Slide shows – projectors designed for business graphics render poor photographic

quality and awful color. More megapixels = bigger files = more storage + faster computers


Which Is Better?The apple or the orange?

Each has their respective strengths and weaknesses.

It all depends on what you’re trying to accomplish.

Everything in photography is a trade-off.


Choosing A Digital Camera

The number of megapixels isn’t everything!

More is not necessarily better,But more can be an advantage when cropping or

printing big.


Megapixel Madness


How Many Pixels Do You Need? Assume 300 dpi (dots per inch) for a good quality print

on a desktop printer Break down megapixels to length and width, then divide

by 300e.g. 6MP ~ 3008 x 2000 pixels (Nikon D70)

3008/300 = 10.027 in. 2000/300 = 6.667 in.

BUT, different printers have different requirements Software can help upsize or downsize with varying

results Large fudge factor, depending on chosen application

and printer technology.


Digital Camera Resolution Chart(Source: B&H Photo-Video-Pro Audio)

Print Size* * * Capture Resolution Video Display* 2x3" 4x5"/ 4x6" 5x7" 8x10" 11x14" 16x20"

320x240 Acceptable Good Acceptable Poor Poor Poor Poor 640x480 - 0.3 Megapixel Good Excellent Good Poor Poor Poor Poor

800x600 Excellent Photo Quality Very Good Acceptable Poor Poor Poor

1024x768 Excellent Photo Quality Excellent Good Acceptable Poor Poor

1280x960 - 1 Megapixel Excellent Photo

Quality Photo

Quality Very Good Good Poor Poor

1536x1180 Excellent** Photo Quality

Photo Quality Excellent Very Good Acceptable poor

1600x1200 - 2 Megapixel Excellent** Photo

Quality Photo

Quality Photo

Quality Very Good Acceptable Acceptable


Quality Photo

Quality Photo

Quality Excellent Good Acceptable


Quality Photo

Quality Photo

Quality Photo

Quality Very Good Good


Quality Photo

Quality Photo

Quality Photo

Quality Excellent Very Good


Quality Photo

Quality Photo

Quality Photo

Quality Photo

Quality Excellent

Poor Noticeably Grainy (pixelated) Acceptable Obviously not a real photo, but some details are visible Good Can tell it is not a photo but most details are discernable Very Good Can tell it is not a photo at normal distance, but good enough for many uses Excellent Difficult to tell from real photo at normal viewing distance Photo Quality On a photo-quality printer, the human eye should not be able to tell the difference at a normal

viewing distance * Either television or computer display (e.g. Web Page) ** Will produce an excessively large file size that would be inappropriate for web applications *** Using a typical Photo Quality Desktop printer

http://www.bhphotovideo.com/bnh/controller/home?O=getpage.jsp&A=getpage&Q=Product_Resources/resolution_chart.jsp


So, How Do I Choose A Camera? Ergonomics – how does it feel in your hands? Size and weight of the camera Size and quality of the LCD Lens quality

Sharpness Distortion Zoom capability (optical vs. digital)

Digital zoom is evil! Metering capability Built-in flash

Red-eye reduction Can you control it?

Manual capability vs. automatic or program modes Battery life Media type Decide what’s important to you based on how you’ll be using it!


About The CardsPick One

Compact Flash SD MiniSD xD

MultiMediaCard RS-MMC (Reduced-Size

MultiMediaCard)

SmartMedia Memory Stick

Image source: Lexar

http://www.lexar.com/digfilm/index.html


I Bought A Camera… Now What? Charge the battery Format the card Set up the camera

Date and time Bells and whistles (literally!) Digital zoom – if you can turn it off, do it! Mode: Auto, Program, Aperture Priority, Shutter Priority, Manual ISO White balance Color space (Never mind!) Image quality and file type

JPEG (Joint Photo Experts Group) – in-camera processing, lossy (small, medium, large), 8-bits (256 shades of color) per channel (16.7 million colors)

TIFF (Tagged Image File Format) – in-camera processing, uncompressed, lossless, 8-bits per channel

RAW – direct output from the sensor, little to no in-camera processing, 12-bit (4096 shades of color) per channel (68.7 billion colors)

What are you waiting for?? Go shoot pictures!


Recall…

Good photography depends on being able to execute two things well:

ExposureComposition


Composition

“The art of including the essence of what moves you about the

scene in your photograph, while excluding any non-essential,

distracting elements.”


Composition There are established “guidelines”,

but ultimately, it’s about your artistic vision

Very subjective Not always a conscious thing –

listen to your heart! Simplify, Simplify, Simplify!


Simplify


Simplify


Simplify


Simplify


Simplify


Simplify


Composition “You take the picture, but you make the photograph.” It’s about seeing the photograph in front of you. It’s about design – arranging all the elements of the

scene in your viewfinder so they become something compelling to look at.

Hold the viewers’ attention as their eyes travel around the frame.

Check your corners! Move your eye around the frame in the viewfinder looking for anything that might distract attention away from your subject(s) – a stray branch, somebody’s toe, etc.

Our eyes are naturally drawn to brighter, “hotter” elements. If those aren’t your subject(s), exclude them!


Composition Do in in the viewfinder, not in Photoshop! It’s always

best to start with a good image. “Photoshop doesn’t make a bad photograph good, it makes a

bad photograph big.” You’re rendering a 3-D scene as a 2-D print. Frame it

carefully! Try not to “bullseye” your subject in the frame. Dead

center is deadly! Use the “Rule Of Thirds” – the oldest trick in the

book for composing a visually balanced and pleasing image.


Rule Of Thirds

Divide your scene into an imaginary “tic-tac-toe” grid, then place your subject(s) near any of the four intersections


Use Those Lines!

Diagonal lines are especially dynamic. Use them to lead the viewer to the subject, guide the viewer across the frame or create “vanishing points”.


Find GraceThe S-curve is a classic compositional device to create a sense of grace.

Give moving subjects space to go. Don’t place them so they are about to run off the frame.


Tips For Better CompositionTry not to cut off any

body parts.

Don’t have trees or telephone poles

growing out of your subjects’ heads.


Tips For Better Composition

Tell a story with your photographs


Learn, Practice, Then ForgetRemember, these are just guidelines, not hard and fast rules.

Don’t be afraid to experiment! Look for different viewpoints.Try tilting the camera. Try it

blurry!

You are only limited by your own creativity!


Now That You Have Your PicturesTime for the workflow

Why do you need a workflow?Because your photos are trapped in your card

and somebody has to liberate them

Because it’s too expensive not to get them out and print/email/put-them-on-the-web yourself

Because you want artistic control over how your photos are displayed


Now That You Have Your PicturesTypical Post-capture Workflow:Download And

StoreFile namingStorageMetadata Edit

Crop/StraightenToneContrastColor correctionSharpeningCataloging

OutputPrinterEmailWeb

Image source: Epson

http://www.epson.com/


Download And Store Downloading directly from the camera can be slow

usually USB 1.1 – maximum transfer rate of 12Mbits/sec. Use a fast external card reader if possible

USB 2.0 capable of up to 480Mbits/sec. Firewire (IEEE 1394) capable of up to 400Mbits/sec.

Software available to download, rename, add metadata Downloader Pro (Breeze Systems) Photo Mechanic (Camera Bits)

File naming is important. Use the same file naming scheme for your edits and originals.

Metadata is essential. Helpyourself find and figure out your photos later.


Backups! Backups! Backups!Copy your newly

downloaded images first thing before you

do anything else!


The Browser Allows you to look at all the photos on your

computer Thumbnails and previews Sorting, ranking Batch renaming Manage metadata

EXIF (Exchangeable Image File Format) IPTC (The International Press Telecommunications

Council) Popular software packages have them built-in

Adobe Photoshop Photo Mechanic iPhoto


The Organizer Builds databases of information about your

photos EXIF IPTC File names Folder names

Allows searching of your photos regardless of where they are

Popular software Adobe Photoshop Elements Extensis Portfolio iView MediaPro Canto Cumulus


Time To Edit Crop and straighten Tone and contrast Color correction Creative sharpening Many software packages available:

Adobe Corel Apple Microsoft Extensis Ulead JASC Nova Free/share-ware Etc.


Why Adobe Photoshop?Because it’s the best!

Because the camera is good, but you might be able to do better in post

Because your in-camera technique is good, but you might be able to do better in post

Because you might have been forced to do something like underexpose on purpose, and

only you know how to deal with that


Why Adobe Photoshop?

Because you may want to create a

piece of art out of your photos…


Adobe Photoshop Family Adobe Photoshop Album 2.0 – casual snapshooters

Adobe Photoshop Album Starter Edition 3.0

Adobe Photoshop Elements 3.0 – photo enthusiasts and most amateur photographers (This is probably all you need!)

Adobe Photoshop CS2 – professional gold standard


Sharing Your Photos Print

Desktop printers Commercial printing services

Shutterfly, Ofoto, etc. Costco

Web Online services

Shutterfly, Ofoto, etc. Web pages (72 dpi)

Email Good for small files only! (72 dpi)


Printing Tips Set the print size Set the correct printer and paper (including size,

orientation, fit on paper) Your software gives you options, then your printer

gives you options – can be confusing Color management – either let your software

manage the colors, or let the printer do it, but not both!

Set the color profile of the paper you’re using Do a nozzle check beforehand. (Keep scrap plain

paper around!) Clean the nozzles often. Use third-party inks and paper at your own peril!


Email Tips If you don’t have to, don’t! Don’t email big files! Anything ~1M or

more is too big! Use software emailing features, or

manually reduce the file size (72 dpi, 640 pixels is usually sufficient).

Package up your images if you have many – zip, etc. Better yet – use the Web!

Attach the images – avoid placing them in the body of your email (in-line).


Web Tips If you have already enhanced your photos,

make sure your service (Shutterfly, Ofoto, etc.) doesn’t enhance them again!

If you manage your own web pages, use small files (72 dpi)

Software available to create galleries Adobe Photoshop CompuPic ThumbsPlus


Sharpening In digital terms, adding adjacent light and dark

pixels to enhance contrast Amount – how much (gas pedal) Halo (Radius) – how many pixels affected Threshold – how many surrounding pixels considered

“edge” Different needs

Print: inkjet, laser, offset, etc. Web/email (screen) After resizing

Schools of thought For output only Workflow (artistic) sharpening


Live Editing Session…


Parting Thoughts

“Good art comes of good craftspersonship.”


If It Moves You, Shoot It! Often!Anything and

everything!

Practice! Practice! Practice!


Recommended ReadingPhotographyBlue Pixel Personal Photo Coach: Digital Photography Tips from the Trenches by David SchlossPerfect Exposure: Jim Zuckerman's Secrets to Great Photographs by Jim ZuckermanDesigning a Photograph: Visual Techniques for Making Your Photographs Work by Bill Smith Examples: The Making of 40 Photographs by Ansel AdamsSuccessful Underwater Photography by Brian Skerry, Howard Hall

Adobe PhotoshopAdobe Photoshop CS2 for Photographers by Martin EveningThe Photoshop CS2 Book for Digital Photographers by Scott KelbyThe Photoshop Elements 3 Book for Digital Photographers by Scott KelbyPhotoshop Restoration & Retouching by Katrin EismannPhotoshop Masking & Compositing by Katrin EismannThe Photoshop Show Starring Russell Brown by Russell BrownAdobe Photoshop CS2 Classroom in a Book by Adobe Creative TeamAdobe Photoshop Elements 3.0 Classroom in a Book by Adobe Creative Team

Photoshop on the WebAdobe Photoshop (http://www.adobe.com/products/photoshop/overview.html)National Association of Photoshop Professionals (NAPP) (http://www.photoshopuser.com/)Photoshop News (http://photoshopnews.com/)Photoshop Café (http://www.photoshopcafe.com/)Adobe Evangelists (http://www.adobeevangelists.com/)

http://www.amazon.com/exec/obidos/tg/detail/-/0321305280/qid=1124235984/sr=1-1/ref=sr_1_1/102-2912015-9579332?v=glance&s=books

http://www.amazon.com/exec/obidos/tg/detail/-/1582971269/qid=1124236447/sr=1-1/ref=sr_1_1/102-2912015-9579332?v=glance&s=books

http://www.amazon.com/exec/obidos/ASIN/0817437789/qid=1124236070/sr=2-1/ref=pd_bbs_b_2_1/102-2912015-9579332

http://www.amazon.com/exec/obidos/tg/detail/-/082121750X/qid=1124237404/sr=1-1/ref=sr_1_1/102-2912015-9579332?v=glance&s=books




Thank You For Coming!

Now Go Take Pictures!

Peter LiuPhotographykaiscapes.com




Supplemental Slides Begin Here


Film Speed Trivia ASA – American Standards Association. Most

common film speed rating in the U.S. until the conversion to ISO. Only the name has changed.

ISO – International Standards Organization. Most common film speed rating in the U.S. Doubling the value doubles the film speed.

DIN – Deutsche Industrie Norm. Based on a logarithmic scale where each increase represents 1/3 stop. E.g. ISO 800/30 on a roll of ISO (ASA) 800 film indicates that the DIN rating is 30.