Sigma SD15 User Manual

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Exposure.
The amount of light reaching the image sensor’s surface. The exposure is
controlled by the combination of aperture and shutter speed.
EV
Exposure Value (EV) is a numerical value that expresses the amount of light for a
given exposure, and depends on brightness of the photographic subject and
sensitivity of the film. If a photographic subject is bright, then this numerical value
will be large, and if the subject is dark then this numerical value will be small. If
two-times of light reaches the film surface then the difference in exposure value
will be +1, and if the amount of light is reduced by half, the exposure value
changes by -1.
Histogram
The histogram function is a graphic representation of how bright and dark pixels
are distributed in an image. The histogram function enables a precise check on
the exposure of the photo.
ISO Sensitivity
ISO（International Organization for Standardization ）; refers to the number
assigned to each silver halide film, which indicates film speed or the film's relative
sensitivity to light, the higher the number, the greater photosensitivity and vice
versa. Digital cameras also use standard ISO sensitivity ratings like silver halide
films.
JPEG
Joint Photographic Experts Group has established a standard method for
compressing and decompressing the digitized images. If the rate of compression
is high the file size will be small but picture quality will be decreased.
NTSC
National Television Standards Committee (NTSC) video format is primarily used
in the United States, Japan, Canada etc. The NTSC is a standard for television
and videos, which defines a composite video signal with a refresh rate of 60
half-frames (interlaced) per second. Each frame contains 525 lines and can
contain 16 million different colors.
PAL
Phase Alternating Line (PAL), video format primarily used in Europe, excluding
France, as well as Australia and parts of the Far East. PAL delivers 625 lines at
50 half-frames per second.
RAW
The RAW image format is the data as it comes directly from the image sensor of
the camera. No in-camera processing is performed before transferring the image
to computer.

Sigma SD15 Specifications

General

Camera Type	Interchangeable Lens SLR Type Digital Camera
Image Sensor Size	13.8 x 20.7mm
Lenses Used	Sigma SA Mount Lenses
Picture Angle	Equivalent to 1.7x the focal length of a lens when used on a 35mm SLR camera.
Lens Mount	SA mount
Imaging Element Type	FOVEON® X3™ (CMOS)
Color Photo Detectors	14.06 Million (2652 Columns x 1768 Rows x 3 Layers)
Image Recording Format	Lossless compression RAW Data (12bit), JEPG
White Balance	8 Type (Auto, Sunlight, Shade, Overcast, Incandescent, Fluorescent, Flash, Custom white balance)
Viewfinder Type	Pentaprism SLR Viewfinder
Viewfinder Frame Coverage	98％ horizontal, 98％ vertical
Viewfinder Magnification	0.9x (50mm F1.4 at infinity)
Eyepoint	18mm
Diopter Adjustment Range	-3dpt to +1.5dpt
Auto Focus Type	TTL phase difference detection system
AF Operating Range	EV 0 to 18 (ISO100)
Focus Mode	Single AF, Continuous AF (AF Predict function), MF
Metering Systems	Evaluative Metering, Center-Weighted Average Metering, Center Area Metering, Spot metering
Metering Range	EV 1 to 20 (with 50mm F1.4 at ISO100)
Exposure Modes	(P) Program AE、(A) Aperture Priority AE、 (S) Shutter Speed Priority AE、(M) Manual
ISO Sensivity	ISO (50), 100, 200, 400, 800, 1600, (3200) *( )Extended Mode
Exposure Compensation	±3EV (in 1/3steps)
AE Lock	Push button type
Auto Bracketing	Three or five frames (in 1/3steps, Appropriate Exposure – Under Exposure – Over Exposure)
Shutter Type	Vertical-travel metal focal plane shutter, electronically controlled through entire speed range
Storage Media	SD Card / Compatible with SDHC, Multi Media Card
Aspect Ratio	3：2
Resolution	HI：2640 x 1760 MED：1872 x 1248, LOW：1312 x 880
Interfaces	USB 2.0, Video Out (NTSC／PAL)