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An Introduction to Digital Cameras and Digital Photography
December 14, 2016
• Getting started, picking a camera
• Photography in the “Digital Age”
• Understanding the big picture of how digital cameras are designed (demystification)
• How to set up and use a digital camera to do “Digital Age” photography
• A simple approach to processing digital images
• Appendix – cropping and downsizing images, getting digital images into your computer and organizing them
• Digital cameras are computers with a lens • Digital Camera complexity needs to be dealt with
• Modes, settings, controls Camera companies are really bad at communication
We will strive to explain and demystify the complexity
• There is a simple explanation for how digital cameras are designed; it’s all about control
• Point and shoot cameras are at one extreme • Cameras in totally manual mode are the other extreme • In between is where we live
We will go over key photography basics and show you how to set up and use your camera accordingly (no matter what brand)
• Talk will be interspersed with a few “Tech Facts” 2
A Little History
• Ansel Adams spent his career developing his manual exposure technique and darkroom printing of B&W pictures
• Color film became popular in the 1950’s • In 2000’s, digital sensors replaced film • Photoshop has largely replaced the darkroom • All digital cameras now have Auto Exposure & Auto Focus
1950’s
2000’s
sensor
3
What’s Changed In Today’s “Digital Age” Photography
• Auto Exposure and Auto Focus frees up a lot of time
• You don’t have to worry about the cost of film
• You don’t have to wait hours or weeks to see your images
There is a powerful way to instantly review your images when you take them
There is a convenient and powerful way to immediately correct camera settings and retake each sub-standard image
• No time spent in the darkroom to see final results (limited by chemistry)
Digital post-processing is rapid and powerful, and opens the creativity door wide open (beware of the danger of being able to do many things many different ways)
• Requires a physically-based approach, not a random trial and error process development
Key Driving “Digital Age” Developments 4
Something You Probably Already Know
• Digital picture size is specified by the number of pixels
• Pixel = Picture Element
• Number of pixels also drives the storage required on your computer for storing a picture, measured in Megabytes (MB)
• An example : a 24 Megapixel image with an aspect ratio of 3:2 is 6,000 pixels wide x 4,000 pixels high [that’s 24 million pixels]
5
The GeoEye-1 Satellite Camera – A True Digital Camera
• Orbital Sciences had contract to build satellite, integrate camera • Assembly of camera/spacecraft in Satellite Factory in Gilbert, AZ
• One of two main sources of Google Earth pictures for the last 8 years
Launched on September 6, 2008
6
GeoEye Satellite Camera Pictures
The very first picture taken by the GeoEye Camera
•Note the tennis players on the bottom court
• From 425 miles altitude 7
GeoEye Satellite Camera Pictures
• Presidential Inauguration January 2009
• Yes, those dots are over a million people 8
GeoEye Satellite Camera Pictures
• GeoEye camera cost $84 Million dollars • D90 was about $900 in 2009
Consumer Reports Review*
Metric Geoeye-1 Nikon D90 Notes
Mpixels/image 2,100 12.2 for 24x36mm format
Type of images Pan + 4 colors Color both have B&W, RGB color
Size of picure frame needed 187.6" x 125" 14.3" x 9.5" At 300 dpi
Time to fill up 500GB HD [min] 4.1 101.2 D90 at 4.5 fps 12 bit jpeg
Battery life [hrs] 1.8 17 (4) GE-1 contin./D90 100 images/hr
(1) - hand held use not recommended - use tripod or equivalent
(2) - set Geoeye camera TDI value (Time Delay Integration), based on sun angle & scene angle
(3) - preset camera using focus algorithm
(4) - no flash
* not really
9
How To Select A Digital Camera
To select a camera, start by asking yourself these questions;
1. How are you going to use the camera? • Just around home, family, people • Travel/landscape photography (quality is key) • Sports, kids on the fly, wildlife (speed is key) • Safaris, wet, dusty, cold, humid environments
2. What will you do with the pictures? • Facebook, email, website, small prints (up to ≈ 8”) • Books, wall art • Large format prints (Fine Art)
3. What is your tolerance for carrying around heavy equipment?
• Camera, Multiple lenses, high quality tripod, filters, etc.
4. What is your growth path as a photographer? 10
Digital Camera Types
Point and shoot (P&S) cameras (including phones)
• P&S Cameras do all the settings • Most have heavy duty in-camera processing • Suitable for email, web, small-medium sized prints & books
• ILC is either DSLR (Digital Single Lens Reflex) or mirrorless • Typically heavy (especially with multiple lenses & tripod) • User does camera settings • Pictures usually need at least some post-processing
High quality compacts* (Sony RX100) are becoming a P/SE substitute
Bridge Cameras are an interesting intermediate category
• Small lightweight cameras with built in powerful zoom lens • Great for travel, hiking Some now approach quality and flexibility of P/SE cameras
11
Power of 30x Zoom Lens
25mm focal length
750mm focal length
Panasonic ZS50 at 30x
Panasonic ZS50 at 1x
• Both images were hand held • Camera has optical
stabilization to eliminate blurring from camera movement
• 8 oz • 30x zoom • 10Mpx • Shoots Raw • EVF • P/SE capable
• New ZS100 • 11 oz • 10x zoom • 20Mpx
12
Power of 30x Zoom Lens
750mm focal length
13
MP Format Im Ht Min f/no EFL eq Zoom IQ-W IQ-T C.S. Raw1 Video EVF2 Env. Wt.
All cameras have a built-in flash DSP = dust & splash proof
* and MPEG-4 AVC
C.S. = Color space
s,A = sRGB, Adobe RGB
SensorName Price
Optics HandlingImage Quality
The “Full” List of Currently Available Bridge Cameras*
* Using B&H Photo and DPR websites
= New
= Consider = Added 041216
14
Size of Sensor Is Significant Driver Of Image Quality
APS-C 4/3 1” 1/1.7 1/2.3 Full Frame
Sensor Sizes (to
scale)
Better low light performance (less image noise)
Smaller, lighter weight camera
P&S
SE ILC
Pro ILC
Bridge Camera
High Quality Compact
1/3.2
Phones
ILC = Interchangeable Lens Camera (both DSLR or mirrorless)
• You can rely on camera reviews to assess camera strengths and weaknesses, such as impact of size of sensor used
15
So, If You Are Starting Out In Photography ...
Choice of First camera : Bridge camera, or Interchangeable Lens Camera (ILC) with walk-around zoom kit lens
• DSLR or mirrorless ILC can be starter (Nikon D3300), or intermediate (Nikon D5500), or serious (Nikon D7200), or Pro (D500); Sony P6500, or Canon, or ...), based on features
ILC growth plan : • Add lenses (wide angle zoom, long FL zoom, ...)
• Added lenses will tend to be better & more expensive • Add very good (and expensive) tripod (spend the money!)
Bridge Camera growth plan :
Start with P/SE- like Bridge camera, then buy ILC (or not)
• Main feature should be in focus (especially the eyes)
• Often, you want the background blurred out (bokeh)
Exposure Control
• Capture bright and dark scene elements (camera settings)
• Optimize the contrast (usually done in post-processing)
Mobility, Luck
• Get out there and find opportunities - catch that special moment when the lion looks right at you ...
Plan Ahead
• Envision a photograph, make it happen
Creativity
• Path to establishing YOU as a photographer 17
These Are The Digital Camera Factors
Subject, Lighting, Composition
• The traditional big 3
Focus Control
• Main feature should be in focus (especially the eyes)
• Often, you want the background blurred out (bokeh)
Exposure Control
• Capture bright and dark scene elements (camera settings)
• Optimize the contrast (usually done in post-processing)
Mobility, Luck
• Get out there and find opportunities - catch that special moment when the lion looks right at you ...
Plan Ahead
• Envision a photograph, make it happen
Creativity
• Path to establishing YOU as a photographer 18
Result of a critique of 60 or so images taken by a diverse group of photographers
• Purpose of any critique is to indicate where pictures can be improved • No judgments – not a matter of liking a picture • Purely a technical assessment of the techniques of
image capture and processing
Where Are The Challenges In Digital Photography?
Rank #
1 21 highlights & shadows
2 14 Composition/cropping
3 10 brightness
4 8 Overall sharpness
Most recurring "Needs work" critique
Critique
/contrast
Exposure Control
Focus
Exposure Control dominates; Let’s address Focus first 19
Focus Control (Poor)
Collman – Changing of the Guard in Copenhagen
20
Focus Control (Prizewinning)
Collman – Changing of the Guard in Copenhagen
21
1. f/no selection
• Low : blur/isolate background (bokeh) • Mid : optimize quality (typically ~2 stops above base f/no) • High : increase depth of field
2. Hyperfocal distance calculations (4 parameters are involved)
• Overly complicated; internet calculators are outdated
3. Focus stacking (go to FHPC/Events and Information page, look at Hand Held Focus Stack report under Misc. Information)
• Tripod (many images) • Hand held (2 images)
Techniques for Controlling Focus
22
Hand Held Focus Stacks
When you want both your foreground and background to be in focus in a single picture, and you don’t ... a) have your beloved tripod handy (or you hate tripods), b) have a supercomputer to do hyperfocal calculations
Approach in a Nutshell • Take 2 pictures, one focused on the foreground, and one
focused on the background, stack them in Photoshop
+ =
B.Boyce 6/9/16 (updated) 23
Hand Held Focus Stack Example
24
Example of Poor Exposure Control
• Blown out scene elements is a very common, often difficult problem to deal with 25
Example of Good Exposure Control
• Good Exposure Control is a combination of camera settings, processing, and image file type 26
Meet the Histogram – Your New Best Friend
Think of each pixel in your camera’s sensor as a very small light bucket collecting particles of light (photons)
• A histogram shows the distribution of the amount of light (Luminance) in all the buckets (i.e., pixels)
# or % of
pixels Good histogram !
Bad histogram !
0 255 brighter pixels
0 255
Basic Principle; when shooting pictures, capture entire histogram
Bad histogram !
Blown out (saturated) pixels are white pixels
Totally black pixels
Pixel values =
MOST IMPORTANT
CHART
27
Bad histogram ! Bad histogram !
Histogram Tells You When You Have The Proper Exposure
Good histogram !
Automatic Camera
Exposure Setting
(stick with default setting)
(Default)
vs.
28
Set camera to show histogram when picture you take is displayed
Critical - For each picture, look at the histogram on camera LCD
• Histogram will tell you if you have captured a good image • If not, adjust Exposure Compensation*, retake picture • Particularly important with sunlit clouds in landscapes
Histogram is much easier to see on LCD in bright sunlight than the picture itself (white on black) – you can trust the histogram!
Why The Histogram Is So Important
Nikon 3300 Panasonic ZS50 Sony RX100M3
* A control unique to digital cameras – much more on this later 29
More About Your Best Friend the Histogram
For color images, there are actually 3 numbers in each pixel, for each of the 3 primary (Red, Green & Blue, aka RGB) colors
• Two kinds of histograms – RGB and luminance (total light)
# or % of
pixels
0 255 brighter pixels
Red, Green & Blue (RGB) Histogram
Luminance Histogram
• Picture too blue? You can selectively process each color • Bright red flowers saturating? You can desaturate the red
This is the one you will likely see on your
camera LCD
30
Introduction to Black & White Photography
• You can easily make black & white images from color images using Photoshop
Red Green Blue 31
Introduction to Black & White Photography
32
The amount of light collected by each pixel is proportional to
• Shutter exposure time texp
• Electronic sensitivity (ISO) (essentially like a dimmable lamp) • f/no of the lens : f/no = focal length / aperture diameter • Exposure Compensation factor ΔEV [key camera adjustment] • Manual adjustment to camera’s auto exposure determination
Critical definition – the “stop”
• A “stop” is a factor of 2 change in brightness of an image • Increasing the shutter integration time by factor of 2 (“one
stop”) doubles the collected light • Note that a decrease in f/no by a factor of 1.4 (“one stop”)
doubles the collected light • Exposure Compensation factor of +1 (“one stop”) doubles the
collected light
Four Camera Parameters Determine the Exposure
MOST IMPORTANT
BULLET
33
An Example of Correcting an Improper Exposure
Picture Retake Exposure Compensation ΔEV = +2
First Picture Exposure Compensation ΔEV = 0
1 stop
If you see this, you need to increase Exposure Compensation and retake the picture
Result
34
Jpeg Picture Right Out of the Camera
35
Jpeg Picture After Some Very Simple Processing
36
Before and After Processing Histograms
Directly out of camera
After some simple processing 37
Processing Can Be Viewed As Histogram Manipulation !
Directly out of camera
After some simple processing 38
Answer : Shoot Raw
• Jpeg images (8 bit) contain 256 discrete levels of each of the primary colors (R, G, B) in every pixel
• A properly exposed Jpeg image looks fine, but • There are severe limits to recovering problem images
• Raw images (12-14 bit) contain 4,096 to 16,384 discrete levels of each primary color (R, G, B) in each pixel
• 16x to 64x more data allows you to recover dark shadows and blown-out highlights quickly (simplifies processing)
• Raw files are much bigger files (2x to 8x bigger, depending on jpeg quality you are comparing to)
• You can set camera to record Raw & Jpeg (L, M, H quality) files for every picture
You should still use the Histogram/Exposure Compensation method for good histograms when shooting Raw
How Else Can We Make It Easier To Get A Good Histogram?
39
-3EV -5EV -1EV
+1EV +5EV +3EV
• Take an exposure bracket set of 6 Raw images • Now let’s look at the corresponding histograms for these
images
High Dynamic Range (HDR) Image Example (>10 stops)
What do you do when you can’t get a “Good” histogram?
40
Histograms Clearly Show No One Histogram is “Good”
-3EV -5EV -1EV
+1EV +3EV +5EV
41
Put Them Together, You Can Recover The Image
• Requires Dedicated HDR Program
42
So Far, we’ve learned that in digital photography, ... • Exposure control is the toughest photographic challenge • Exposure is determined by f/no, ISO, texp and ΔEV • The Histogram is key “quality control” tool for correcting
camera auto exposure calculations to get better images • Exposure compensation (ΔEV) is the key camera setting for
adjusting the camera to get good histograms • Shooting Raw will help (easier to get good histograms in
high contrast situations, makes processing much simpler) • Not required, but most serious photographers shoot
Raw pretty much 100% of the time
After the Break : Using the camera to take good pictures
• Camera Mode selection • Camera Key Settings • A simple processing recipe (histogram manipulation) • Saving pictures to your computer
Break Time
43
Exp
osu
re C
om
pe
nsa
tio
n
Raw files
Step Up To Great Exposure Control !
44
Camera Modes – What Are They, really?
Record Mode Dial
Zoom lever (W to T) Movie
Shutter Release Nikon D3300
Panasonic ZS50
Sony RX100 M3
• All 3 cameras have Auto, SCN, P, A, S and M Modes
• All 3 cameras come from different companies
• All 3 cameras have complex menus for setting up the camera
• But all 3 cameras allow you to set important parameters w/o going through the complex menus 45
Warning !
The Next 2 Charts Should Be Consumed Very Carefully; Do Not Try This At Home, Or If You
Are Prone To Dizziness
The Next Page Shows You 3 Tables On How To Set All Exposure Parameter Values For Each Of
The 3 Cameras To Operate In Each Of The Cameras’ Modes
You Will Notice That The Overall Tables Are
Very Similar, But Not Identical
We Need To Determine What Modes Can Be Used To Execute The Exposure Control
Process We’ve Been Talking About
46
Digital Camera Rosetta Stone
• Selected Mode determines how much control you have Camera is in control
User is in control
Record
Mode
iA
(intelligent Auto)
SCN
(Scene)
P
(Auto Exposure)
A
(Aperture priority)
S
(Shutter priority)
M
(Manual)
What does the User
have control of?
Fully Point & Shoot –
camera does the settings
Point & Shoot for selected
scene types
User sets ISO, ΔEV, camera
picks f/no and texp
User sets f/no, ISO,
ΔEV, camera
picks texp
User sets texp , ISO,
ΔEV, camera
picks f/no
User sets all the
settings
Why select Mode?
Ease of shooting
under normal &
tough conditions
not demanding
max quality
Ease of shooting
under specific
and varied scene
conditions
Transition Mode : Enable
Exposure Compen-
sation, Raw filetype
(A,S,M also)
Pick f/no to
maximize image
quality, isolate scene
features, increase depth of
field
Pick shutter texp to
Minimize blur of moving water,
objects, people or animals
Macro imaging, night or studio
photog-raphy, other
specialized imaging
47
How To Set Exposure Parameters On 3 Different Cameras
• The green settings are accessed through the shortcut menus, buttons, dials & wheels on the specific cameras!!
• The blue settings are accessed through the main Menu
ΔEV wheel ↓ wheel ↓ wheel ↓ estimatetexp x x wheel w↓, w
ISO ring ring ring ring
f/no wheel wheel x w↓, w
Raw files yes yes yes yes yes yes
x denotes camera calculation = F/no, texp texp f/no # stops
Nikon
D3300
Panasonic
ZS50
Sony
RX100
P,A,S,M
P,A,S,M
SCN, P,A,S,M
50
p. 222 p. 231
Nikon Manual For D3300 (392 pages)
51
Pgs. 118-119
Exposure Compensation
Flash Compensation
See Pgs. 120-121
Set Aperture (f/no)
Pg. 107
Pg. 105 Pg. 105
Pg. 95
Nikon Manual For D3300 (392 pages)
52
Panasonic Manual For ZS50 Advanced Features (305 pages)
53
Toggle between Record and Playback Modes (you can turn the camera on without using the ON/OFF button by holding this button for a few seconds)
Programmable buttons : (Fn2 factory default toggles display between Auto, Monitor and LVF; Auto shows display on LVF when eye is placed there, otherwise Monitor is used)
ERASE displayed image; also functions as access to Quick Menu (Q.MENU) when camera is in Record mode; also functions as “CANCEL” DISP toggles through 3 or 4 different
image displays on Monitor & LVF
MENU/SET Button to enter Menus and confirm selections
• The Recipe uses both Camera Raw and Photoshop • Works for both Jpeg and Raw files • The basic operations are also in other Processing
programs, so this recipe is largely S/W independent
Supports all 3 programs
58
• To open an image, open Photoshop, click ‘File/Open’, then browse to folder containing the file, and double click the file
• If it’s a Jpeg file, it will open in Photoshop
• If it’s a Raw file, it will open in Camera Raw*
How to open a Jpeg or Raw File
* You can also open a Raw file by going to the folder holding the image file, and double clicking the file – file will open in Camera Raw.
59
Moving From Photoshop Into Camera Raw
60
This is the Camera Raw Screen
Click ‘Open Image’ or ‘OK’ to go back to Photoshop 61
This is the Camera Raw Screen with Larger, Readable Slider Labels
• Nothing has been done – sliders are at zero 62
• Highlights to -100, Shadows to +100, Exposure to center the histogram (check to be sure picture looks good)
1. Using Camera Raw Highlights, Shadows and Exposure Sliders
63
Repeat : Think We Can Do Much With This Image?
This Panasonic ZS50 Image is a Raw file
64
Using Camera Raw Highlights, Shadows & Exposure Sliders
Slider settings Highlights* -100% Shadows* +100%
Exposure = +2
• This shows that with a ‘Good’ histogram you can recover image
* Actually went into Camera Raw 2 times for this image
65
2a. In Photoshop, Using Auto Contrast to Improve an Image
• Try it – sometimes it works well
• If not, click ‘Edit’, then click ‘Undo’, or another command that has the same meaning
• Then go to chart 68 for an alternative more powerful command
66
2a. In Photoshop, This Is What Auto Contrast Gives You
67
With your cursor, you can drag these points around; try
it and see what happens to the
image darker darks
brighter brights
2b. In Photoshop, Using Curves to Improve the Contrast of an Image
68
• Improved contrast reflected in wider histogram
2. In Photoshop, Using Curves to Improve the Contrast of an Image
69
Out Of Camera image (properly exposed to get ‘Good’ histogram)
After taking care of Highlights, Shadows &
Exposure in Camera Raw
After optimizing Contrast & Exposure in Photoshop using Curves
How The Processing Recipe Affects The Histogram
70
Monument Valley - Before
71
Monument Valley - After
72
Monument Valley - Before
73
Monument Valley - After
74
75
How to Crop An Image
76
How to Downsize An Image
• Width of 600 to 1000 pixels is good for many purposes (web, emails, etc.)
77
2. Go to Windows Explorer (Finder on a Mac) and find the camera (to the camera, it looks like a Removable Disk); open up camera file structure
3. Look for DCIM folder; picture files will be in subfolder; copy files you want to download, then paste them into destination folder on your PC
Downloading Pictures From Camera to Computer - 1
• Every camera company supplies S/W to organize your pictures and download them from the camera Do not use that software (personal opinion) !
• Instead, download pictures to your computer directly
1. Plug the USB cable into your computer, then plug the cable into the camera (when it’s OFF), then turn on the camera
78
Downloading Pictures From Camera to Computer - 2
4. Suggestion; If you don’t have one already, build a file structure for your photographs on your computer – here’s what mine looks like
• There are more powerful file handling systems out there, like Adobe Lightroom, but this will get you started
• Each time you go shooting, consider giving that shoot its own folder or subfolder, with subject and date in the folder name so you can find the pictures later
5. Use Monitor on camera back when you get home, in dim light look at all pictures and delete any obviously bad files before downloading the keepers
79
What we’ve learned about “Digital Age” photography, ... • The Histogram is key “quality control” tool identifying need to
correct camera auto exposure calculations • Exposure compensation (ΔEV) is the key camera setting for
adjusting the camera to get proper histograms • Shooting Raw will make it easier to capture good histograms
Set up your digital camera to execute “Digital Age” photography • Use Mode that gives you histograms and Exposure Compensation • Learn how to adjust all exposure parameters quickly on camera
Taking pictures technique – for each picture, • Check histogram for acceptability; if not centered, adjust