Canon EOS-1Ds Mark III Professional Products 2010 Brochure - Page 13

TECHNOLOGY AF Focusing Principle Prime lens Subject Focusing plane (Image plane) CMOS area sensor Secondary image-forming lens gathering efficiency (for both the horizontal and vertical line sensors), and greater low light AF sensitivity. In addition, the camera's ability to latch onto subjects with little detail is improved. Lenses (or lens + extender combinations) with maximum apertures as slow as f/5.6 can be used with AF at all focusing points. At the center AF point only, the camera can focus with a lens + extender with a maximum effective aperture as slow as f/8 (using the vertical line sensor only). The remaining 26 AF points are "Assist Points." Each has a single-line vertical sensor, and these points will focus with lenses having maximum apertures f/5.6 or faster. Speed and Predictive-AF Performance The EOS-1Ds Mark III features higher precision AF with the 19 user-selectable, high-precision cross-type AF points and improved low light AF performance. The AF sensor, AF computation method and AF-related electronic circuitry has been designed for the EOS-1Ds Mark III. This robust AF system provides even greater consistency in high-speed sequences when tracking moving subjects. AF Sensor Sensor vertical-line sensitive at f/2.8 Sensor horizontal-line sensitive at f/5.6 Sensor horizontal-line sensitive at f/5.6 Sensor vertical-line sensitive at f/2.8 Separate CPU for AF One important difference between the EOS-1D series and other EOS series bodies is that a totally separate CPU is used strictly for AF processing. (In other EOS bodies, one main processor handles primary camera tasks as well as AF processing.) To attain 10 fps with AI Servo AF (EOS-1D Mark III), the AF CPU and camera CPU are separate, dedicated processors. The 19 cross-type AF points take advantage of the following technologies: • With finer processing steps, the peripheral circuit could be made smaller and the f/2.8 AF sensor area could be expanded. • The secondary image-forming lens (see diagram) is molded glass. By incorporating an aspherical surface on the lens, the focusing area of the f/2.8 light flux could be expanded. Each of the 19 cross-type AF points uses a high-precision horizontal component, with about 3x the focusing precision of the vertical component. The benefit is that AF accuracy at the sensor is enhanced when the photographer needs it most - shooting with fast lenses, at wide apertures. This means that on the actual AF sensor, the horizontal line pairs are significantly farther apart - and thus require a lens with a maxi7mum aperture of f/2.8 or faster in order to operate. At the center AF point, the highprecision horizontal line sensor works with lenses f/4 or faster. In other words, with fast lenses, two benefits are realized: added precision, and simultaneous vertical and horizontal coverage - ideal for focusing on subjects with fine detail. When lenses with slower maximum apertures are used, only the vertical AF line sensor is active at each AF point. Advanced technology in the EOS-1Ds Mark III's AF sensor gives even greater light- Actual AF Point Field-of-View 2.25 3.00 4.00 2.00 6.6 4.5 7.50 AF Sensor configuration : f/2.8 sensors ((Cencer AF point is f/4) : f/(5C.6 sensors With the EOS-1Ds Mark III, the size of a user-selected AF point can be expanded (via Custom Function III-8) regardless of whether the camera is in One-Shot AF mode or AI Servo AF mode. As noted previously, the assist AF points are also used when the camera picks the AF point(s) in Automatic AF point selection mode. For low-light focusing, the EOS-1Ds Mark III is much more sensitive than previous models. The CMOS AF sensor's pixel sensitivity has been improved, thanks to pixel characteristics, a pixel fill factor due to fine semiconductor manufacturing processes and optimized pixel size. As a result, the EOS-1Ds Mark III's AF sensitivity have been improved to EV -1 through EV 18 (at 73°F/23°C, ISO 100). 25 63-zone Metering System The EOS-1Ds Mark III incorporates a 63-zone metering sensor linked to the 19 AF points. The metering sensor is located at the rear of the pentaprism. The 19 AF points in the Area AF are a highly favorable match for the metering sensor's zones. The metering range is EV 0 to EV 20 (at 73°F/23°C, 50mm f/1.4 lens, ISO 100). The following metering modes are provided: Evaluative, Partial, Spot, and Center-Weighted average. Also, AF point-linked Spot metering is possible with C.Fn I -7-1. Partial metering reads approximately 8.5% of the viewfinder and Spot metering reads approximately 2.4%. Evaluative/Center-Weighted average metering Partial metering Spot metering * C.Fn I -7-1 enables AF point-linked Spot metering. Built to Perform: Durable, Rugged, Precise 1-Series Body EOS-1Ds Mark III retains and refines the beautiful curved surfaces and superb basic layout of the EOS-1 series. Ease of operation and holding comfort have been improved appreciably, as has ease of operation with accessories. The camera is designed to be easier to understand and more reassuring. The massive strength of its magnesium alloy body and chassis, combined with complete environmental sealing, means that the camera stands with its forebears as an instrument worthy of the photographers who risk their lives daily to take pictures. All-magnesium Alloy, Including Mirror Box and Chassis level of ruggedness, surface finish and heating processes in manufacturing have been changed for specific highly durable parts. To increase stability and shutter precision, a PR (Photo Reflector) is employed to detect the slit-passing time. For the X-sync contact, the mechanical contact has been eliminated to prevent contact scorching and wear. Shutter Design Specifications Item Specification 1. Type 2. Shutter curtain type Vertical travel, focal-plane shutter Parallelogram link type 3. Shutter curtain blades 1st curtain: 4 blades, 2nd curtain: 4 blades, total 8 4. Shutter curtain materials 1st curtain: Two carbon blades, two duralumin blades 2nd curtain: Two carbon blades, two duralumin blades 5. Drive system 1st curtain: Dedicated torsion spring 2nd curtain: Dedicated torsion spring This Evaluative metering system is based on the concept for the previous 21-zone and 35-zone metering systems. With the optimized 63-zone metering sensor and improved calculations and processing, more consistent and correct ambient and flash exposures are obtained with less influence from the subject. The basic concepts for the 63-zone Evaluative metering are: 1. Metering is weighted on the linked AF point. 2. If there is a very bright object in the picture, the exposure will be increased. 3. In backlit scenes, the exposure will be increased. With dark backgrounds, the exposure will be reduced. The E-TTL II autoflash algorithm uses the same 63-zone metering sensor. While based on the previous system which weighted the metering based on the preflash reading, the EOS-1Ds Mark III has been improved to obtain consistent flash exposures. The major improvements are: 1. Correct flash exposures are obtained even with off-center subjects. 2. The incorporation of lens distance information has been optimized to obtain accurate flash exposures even with highly reflective backgrounds. EOS-1Ds Mark III Magnesium-alloy Body Because of its light weight and strength, magnesium alloy is used for the top, front and rear covers as well as for the memory card slot covers. The chassis and mirror box are also made of magnesium alloy to make the body very strong, rigid and light. The magnesium alloy also works as an electromagnetic shield. It is highly durable, allowing minimal wear even under harsh conditions. Shutter Durability, Tested to 300,000 Cycles The EOS-1Ds Mark III's shutter unit is rated for 300,000 shutter cycles. To attain this Shutter Unit 6. Speed control method Mechanical shutter with tension released by a rotary magnet, all shutter speeds electronically-controlled 7. Curtain speed 8. Shutter speed range 9. Max. flash sync. Approx. 2.3ms/21.0mm 1/8000 sec. - 30 sec. bulb 1/300 sec. 10. Signals 1. X-sync, 2. 2nd curtain travel-completed signal By employing PR signals for the electronic X-sync contact (a semiconductor switch), reliability is improved. By optimizing the sync timing, an X-sync speed of 1/300 second is now attained with EX-series Speedlites. Electronic X-sync Contact Diagram External Speedlite Sync contacts Semiconductor switch (Electronic X-sync contact) MPU Shutter PR Non-Canon flash PC terminal Semiconductor switch (Electronic X-sync contact) 26