Transcript DIGITAL IMAGES AND VIDEO:

DIGITAL IMAGES AND VIDEO:
A SHORT INTRODUCTION
San-Ho Correwyn
DIGITAL IMAGES AND VIDEO:
A SHORT INTRODUCTION
 1 Digital photography
 1.1 Shooting
 1.2 Commonly used icons
 1.3 Editing and archiving images
 2 Digital video
 2.1 Video taking
 2.2 Video editing
1.1 Shooting
When you buy a camera
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Resolution: between 4 and 6 mega pixels (this will result in good prints
on small size)
LCD display: the bigger the display the better you can evaluate the
pictures
Possibility to connect an external flash
Lens aperture: lenses with larger lens-opening can take pictures in
darker situations
Videomodus is a very useful feature
Macro feature: look at the closest distance
Zoom capacity: only look at the optical zoom capacity! (not the
electronic zoom)
Manual focusing is necessary (in bad light conditions or in macro
photography)
Batteries: AA batteries if possible: the cheapest (especially the
rechargeable) and most available type
Price: starts up from 500 €
1.1 Shooting
Possible exposure problems
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Backlight situations: If you photograph in the direction of a light
source (sun, window, lamp,…) the object will be underexposed (a
person for example will become a dark silhouette). To avoid this you
have to overexpose a little or use the fill-in flash.
Flashing in very dark situations: to avoid ‘white ghosts’ on a black
background, try to use the flash modus in combination with a long
exposure time.
White balancing: to adjust the color temperature. Automatic
adjustment works in most cases, otherwise you can set it manually.
Resolution:
 it’s not always necessary to use the full resolution capacity.
 the final quality of the image is determined by both the
resolution (size) and the compression (image quality).
1.2 Commonly used icons
1.3 Editing and archiving images
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JPEG is a very good image format to save your pictures. It’s much
smaller while keeping most of the original quality, but don’t compress
too much. (70%)
There’s a big difference between screen-resolution and resolution.
Example: when your picture looks great on the screen that doesn’t
mean you can print as big as it is on your screen. Because your screen
uses a 72 dpi resolution, while a print needs much more information for
the same size (about 300 dpi).
For archiving and searching purposes it’s important to incorporate
image descriptions (captions) and other information within the image
files. This is also called metadata.
The best way is to do this in the IPTC standard, because it’s supported
by programs like Adobe Photoshop, Fotostation, Cumulus (5.5+)…
You’ll need one of these programs to write your metadata or there’s
also an interesting free tool like Pixvue.
Photo-editing software. Microsoft Photo Editor (for basic image
improvement), Photoshop (professional photo-editing)
Photo handling and/or archiving: Irfanview (free!) Fotostation,
Cumulus,…
2.1 Video taking
Using the camera:
 System: Digital8, this format is comparable with true
digital video cameras. The main difference is that the
data is stored on the older cassette-type Hi8 (much
cheaper, a bit larger)
 Different connections:
 S-VHS: optimal output quality to connect to a
video-recorder
 audio / video cinch
 Firewire / I-link
 USB
 3 modes: off / vcr (for playing) / camera (for
recording)
 Zoom: try not to use the digital zoom because of poor
quality (20x optical)
2.1 Video taking
 Steady shot: to absorb light vibrations of the camera
 Nightshot: by using the infrared light the camera can
record in almost complete darkness!!
(0 lux)
 White balancing: to adjust the color temperature.
Automatic adjustment works in most cases, otherwise
you can set it manually.
 Backlight: will overexpose the image to avoid
underexposed objects in backlight situations (as
explained in the dig. images chapter)
 Photo: only low resolution images (540.000 pix)
2.2 Video editing- copying
 Copy the tape directly to a VHS recorder: connect the
camera to your recorder using the S-VHS or cinch.
This can also be done in opposite direction (VHS to
camera)
 Import the video to your computer for editing: connect
the camera to your computer using the firewire or
USB. Import the film (capture) with the video-editing
software. In Windows XP you can use the standard
video-editing software. There are also more
professional tools like Finalcut pro or Adobe
Premiere. After the editing you can either put it back
on the camera or on a vhs-tape. (Check the video
encoding: PAL or NTSC)
2.2 Video editing
With the video-editing software from Windows XP
(Windows Movie Maker) you can do basic editing:
 capture video from the camera
 import video-files from your computer
 cut movies in smaller parts
 paste different scenes together (ev. with effects)
 add audio (spoken or music)
 add text (between scenes or as a lay-over)
 add effects
 save the final movie in different formats: VHS
(analog) – MPEG – AVI – MOV - DVD