This month's Technical Report introduces the PowerShot S1 IS, featuring a 3.2-megapixel CCD and 10x optical zoom lens (35mm equivalent: 38-380mm), released in March 2004.
The digital camera market, which had been focused on increasing pixel count is taking a different track. These days, many new digital cameras featuring a higher zoom ratios and improved movie function are emerging.
In response to market needs, Canon developed the PowerShot S1 IS (see Photo 1) equipped with the 10x optical zoom lens and a full-fledged movie mode with 640 x 480 pixels at 30 fps. The development concept is as follows:
Digital camera offering stability, high-speed, and advanced movie shooting mode
Feature 1: High-power zoom lens
High-resolution 10x optical zoom lens
| The PowerShot S1 IS features a newly
developed 10x retractable zoom lens (35mm equivalent: 38-380mm) with a f/2.8-f/3.1
aperture (see Fig. 1). Introduction of a mechanism where all lens groups shift during zooming allowed to make zoom lens fairly compact despite of its extensive optical range. Effective arrangement of the aspherical lens and cemented doublet lens is used to achieve optimal aberration compensation. In addition, ghost and flare are reduced by employing super spectral coating like the EF lenses. |
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| Shift-lens image stabilizer (IS) Higher magnification lenses tend to increase the effects of camera shake on image quality. The PowerShot S1 IS is equipped with shift-lens image stabilizer system pioneered by Canon. The shift-lens image stabilizer system corrects the optical path by deflecting the ray bundle. It does this by instantly moving the ''shift lens'' perpendicular to the optical axis depending on the degree of camera shake (see Fig. 2). The effect of camera shake correction is about the same as using a shutter speed two to three steps faster. The shift-lens image stabilizer system works with either still images or movies. |
| High-speed zoom driven with USM The PowerShot S1 IS employs an ultrasonic motor (USM) zoom drive (see Fig. 3), the same proven lens technology used in EF lenses, giving smooth high-speed zooming even with the 10x zoom lens (Table 1). USM provides quick start/stop response and generates almost no sound due to its simple structure. |
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380mm
Six image quality modes
The PowerShot S1 IS allows users to select from a total of six image quality modes in movie shooting. It can record movies continuously up to 1GB in size, depending on camera usage and CF card capacity.
The recordable time for each image quality mode/CF card combination is listed in Table 2.
| Frame rate (fps) | 640 x 480-Fine | 640 x 480 | 320 x 240 | |||
| 30 | 15 | 30 | 15 | 30 | 15 | |
| FC-32MH | 00:15 | 00:30 | 00:20 | 00:42 | 00:46 | 01:31 |
| FC-64MH | 00:30 | 01:01 | 00:42 | 01:25 | 01:32 | 03:03 |
| FC-128M | 01:02 | 02:04 | 01:25 | 02:50 | 03:06 | 06:08 |
| FC-256MH | 02:05 | 04:09 | 02:52 | 05:43 | 06:14 | 12:15 |
| FC-512MSH | 04:10 | 08:19 | 05:44 | 11:26 | 12:23 | 24:23 |
As with video camcorders, the PowerShot S1 IS allows users to take low-ratio compressed VGA (640 x 480 pixels) movies at a full 30 fps, resulting in movies with exceptional image quality. The extremely high quality image is especially evident when shooting in fine mode with its low-ratio compression. Almost no ''block noise'' or ''mosquito noise'' is generated in fine mode.
Zoom and exposure control while shooting movies
With previous models, it was impossible to change the zooming and exposure while shooting movies. However, the PowerShot S1 IS enables not only to change zooming, AF, AE, and Auto White Balance (AWB), but also to perform exposure lock and compensation.
Improved sound quality
Sound quality is one of the important elements in shooting movies. The PowerShot S1 IS offers greatly improved sound quality by doubling the quantization bit rate and sampling frequency from the 8bit/11kHz of previous models to 16bit/22kHz.
High-speed editing of movie files
The PowerShot S1 IS allows users to delete unnecessary scenes from the beginning or the end of a movie in one second segments.
Movie clips can be edited even if there is no free space left on the CF card causing it to stop recording, and thus space can be created.
Playback functions equal to video camcorders
As in video camcorders, playback, fast forward, rewind, pause, next frame, and previous frame operation are possible, as well as instantaneous jump to start or end of a movie clip.
Independent movie button
The movie button (see Photo 2) dedicated for movie shooting is independent of the shutter button to enhance operation of movie mode. The tally lamp at the front of the camera blinks red during movie shooting.
CCD sensor with approximately 3.2 million effective pixels
The PowerShot S1 IS features a CCD with approximately 3.2 effective pixels (total pixels: approx. 3.3 million). Together with the primary color filter, it produces high resolution and fine color reproduction with up to 2048 x 1536 pixels.
High quality image processing with DIGIC, Digital Imaging Processor
High-speed AF and precise AE/AWB based on iSAPS technology
Iris diaphragm gives multi-stop aperture control and elegant blur
Wide range of ISO equivalent speed settings including the high image quality ISO 50
Feature 4: Advanced functions and comfortable operation
Autofocus enabling switching between Continuous and Single
The PowerShot S1 IS allows users to select either Continuous mode to focus continuously even when the shutter button is not pressed, or Single mode to focus only when the shutter button is pressed halfway. Continuous mode is automatically activated when shooting movies.
Registering settings to the shortcut button
The PowerShot S1 IS is equipped with a shortcut button where the frequently used functions can be registered beforehand. The following eight functions can be registered to the shortcut button:
• Resolution
• ISO Speed (still images only)
• Frame rate (Movies only)
• White balance
• Photo effect
• AE lock
• AF lock
• Display off
Built-in pop-up flash
As with EOS SLR cameras, the built-in flash retracts into the camera body when not in use, and pops up and fires automatically if ambient light is low.
Electronic viewfinder
Since PowerShot S1 IS incorporates a wide-range 10x optical zoom lens, the camera uses a 0.33'' electronic viewfinder with 114,000 pixels. It has a field of 100% of the actual shooting image.
Digital zoom continuously changes angle of view (up to about 3.2x maximum, or about 32x in combination with the optical zoom)
The PowerShot S1 IS is equipped with a 3.2x (approx.) digital zoom. Together with the optical zoom, super telephoto shooting at approximately 1216mm (35mm film equivalent) using 640 x 480 CCD pixels becomes possible.
AF range can be set arbitrary
First-curtain or second-curtain sync flash
Two bracketing functions (AE/Focus)
Interval shooting function
Shooting mode with custom mode
Three light metering modes
Photo effects with custom positions
Histogram display of playback image
Audio annotation of up to 60 seconds can be appended during replay
Enlarged display of image for easy confirmation (approx. 2x to 10x)
AE/AF/FE lock feature enabling fixing focus and exposure
Vari-angle LCD monitor with 100% picture coverage
International user interface (UI) supporting twelve languages
Feature 5: Extensive system accessories
| AA-size battery The PowerShot S1 IS uses AA-size alkaline batteries, or Canon's AA-size NiMH rechargeable batteries (NB4-200) (see Photo 3) that are sold separately and are very economical. |
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| Tele-converter enabling shooting at 608mm focal length (approx.) The PowerShot S1 IS supports use of the optional Tele-converter (see Photo 4-a), which increases the focal length of the master lens by a factor of 1.6x or 608mm (35mm film equivalent) at telephoto. With the Tele-converter, users can enjoy a longer telephoto view without the reduction of pixels, and the resultant loss of image quality, that happens with digital zoom. |
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| Wide converter enabling shooting subjects at 26.6mm focal length (approx.) The PowerShot S1 IS can also be used with the optional 0.7x Wide converter (see Photo 4-b), which reduces the focal length of the master lens to 26.6mm (35mm film equivalent) at wide angle. The Wide converter is useful when taking group shots indoors. |
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In order to prevent flare in backlit situations, the use of the optional Canon lens adapter and hood set (LAH-DC10) is recommended.
Feature 6: Digital communication
Direct printing with compatible printers (PictBridge compatibility)
The PowerShot S1 IS supports direct printing, enabling users to output high-quality images by simply connecting the camera to the CP series Compact Photo Printers or direct printing compatible Bubble Jet printers using the dedicated cable. Operation is easily controlled from the camera. The PowerShot S1 IS also supports PictBridge, the new industry standard established last year (2003). This enables direct printing from any PictBridge compatible printer regardless of the manufacturer.
Driver-less computer connection with PTP support (on the latest computer operating systems)
''My Camera'' function with on-camera content creation function
Bundled with a comprehensive package of software applications
Access to ''CANON iMAGE GATEWAY (CIG)'' on the Web (Available only in Japanese)
This issue of the Technical Report introduces the PowerShot S1 IS. Table 3 depicts the major specifications of the PowerShot S1 IS, while Fig. 4 shows the names of exterior controls and parts.
The PowerShot S1 IS Kit comes as shown in Photo 5. There is no recommended retail price.
Table 3 PowerShot S1 IS Major Specifications
| PowerShot S1 IS | |
| Image Sensor | Camera effective pixels: Approx. 3.2 million
1/2.7'' (Total number of pixels: Approx. 3.3 million) |
| Color Filter | Primary color filter |
| Lens (35mm film equivalent) | 38 - 380mm, f/2.8 (W) - f/3.1 (T) |
| Digital Zoom | Approx. 3.2x (Up to approx. 32x in combination with the optical zoom) |
| LCD Monitor | Low-temperature polycrystalline silicon TFT color LCD (Approx. 114,000 pixels, 1.5'') |
| Autofocus System | TTL (Contrast detecting), Continuous/Single, Focusing Frame: 1-point AF (any position is available) |
| Shooting Distance (from the front of the lens) |
10cm - infinity (W), 93cm - infinity (T) |
| Viewfinder | Color LCD viewfinder (Approx. 114,000 pixels, 0.33'') |
| Shutter | Mechanical shutter + Electronic shutter |
| Shutter Speeds | 15 - 1/2,000 sec. |
| Light Metering Method | Evaluative/Center-weighted averaging/Spot (Metering frame with Spot mode: AF-point-linked/Center-fixed) |
| Exposure Compensation | +/- 2 stops in 1/3-stop increments |
| Sensitivity | Auto, ISO 50/100/200/400 equivalent |
| Flash Range | 1.0cm - 4.2m (W), 1.0 - 3.8m (T) (Sensitivity: ISO 100 equivalent) |
| White Balance | TTL Auto + Preset (6 positions) + Custom |
| Shooting Modes | Auto/P/Tv/Av/M/C/Portrait/Landscape/Night scene/ Fast shutter/Slow shutter/Stitch assist/Movie |
| Continuous Shooting | Approx. 1.7 shots/sec. (Large/Fine mode) |
| Image Recording Format (Still Image) |
(Superfine/Fine/Normal) x (Large/Medium 1/Medium 2/Small) |
| Number of Recording Pixels (Still Image) |
Large: 2048 x 1536 pixels, Medium 1: 1600 x 1200 pixels, Medium 2: 1024 x 768 pixels, Small: 640 x 480 pixels |
| Movie | 640 x 480 pixels, Fine: 30 (15) fps, 640 x 480 pixels: 30 (15) fps, 320 x 240 pixels: 30 (15) fps |
| Recording Media | CF Card Type I / II |
| Color Space | Standard (sRGB) |
| File Format | DCF (Exif 2.2), DPOF-compliant |
| Power Source | AA alkaline x 4, AA NiMH Battery (NB-2AH) x 4, Compact power adopter: CA-PS700 (option) |
| Dimensions | 111.0 x 78.0 x 66.1 mm (Excluding viewfinder eyepiece and protrusions) |
| Weight | Approx. 370g (camera body only) |
