|Our all-new, top-of-the-line flagship, the EOS-1Ds Mark III professional digital SLR camera with a 35mm full-frame 21.1-megapixel CMOS sensor|
|EOS-1Ds Mark III|
|In this technical report, we examine the EOS-1Ds Mark III digital SLR autofocus camera. This top-of-the-line professional model features a 35mm full-frame 21.1-megapixel CMOS sensor, dual DIGIC III image processors, a high-resolution 3-inch LCD monitor, and continuous shooting speeds as fast as 5 fps.|
|Photo1: EOS-1Ds Mark III|
Facing a rapidly changing market environment, we adopted as our development slogan ''REVOLUTION: Speed, Ease, and Image Quality'' for the EOS-1Ds Mark III (Photo 1). Based on the EOS-1D Mark III, which was a completely new design, the EOS-1Ds Mark III was designed to be our flagship EOS digital camera, aimed mainly at professional studio and landscape photographers. Below are some of our specific development aims.
• Ultra-fine detail and top image quality
· 35mm full-frame 21.1-megapixel CMOS sensor
• High burst speed, fast response, and high reliability
· Five fps continuous shooting with a 56-shot maximum burst
· New fast and accurate Area AF (using 19 cross-type AF points and 26 assist AF points)
• Advanced features demanded by pro users
· High-performance viewfinder with 0.76x magnification and wide coverage
· EOS Integrated Cleaning System
· Live View shooting
· New compact, lightweight high-performance battery system
· High-resolution 3-inch LCD monitor
· Maintain the operability found across the EOS Digital line
• Enhanced system features
· New wireless LAN support
· Connectivity for external recording media/GPS devices
· Original image verification and image encryption features
We continue with a survey of the model's features, highlighting the differences from the EOS-1D Mark III.
Advances in image quality, resolution, and digital functions
(1) Large CMOS sensor with 21.1 effective megapixels
The EOS-1Ds Mark III boasts a number of advances giving it the best resolution and image clarity in the digital SLR autofocus class, including a newly developed large CMOS sensor (Photo 2) with 21.1 effective megapixels (21.9 total megapixels) and an effective sensor size of about 36 x 24 mm, an RGB color filter, and a three-layer, high-performance low-pass filter with hybrid infrared blocking.
The camera has both lower noise characteristics and lower power consumption thanks to the addition of a second-generation on-chip noise-elimination circuit, a new output amplifier, manufacturing process improvements, and optimization of the pixel amplifier and 8-channel read circuitry.
|Photo 2: 35mm full-frame CMOS sensor|
(2) New Dual DIGIC III image processors
By arranging two DIGIC III image processors in a dual configuration for parallel signal processing, the EOS-1Ds Mark III is capable of processing enormous 21.1-megapixel images at speeds up to 5 fps with fine picture fidelity and natural color reproduction. Like the EOS-1D Mark III, the new model is equipped with the following new features:
· 14-bit A/D conversion for richer tonal expressions
· Highlight Tone Priority mode
· Noise reduction at high ISO speeds
(3) Full-time ISO 100 - 1600 range, as the EOS-1Ds Mark II
Although its pixels are physically smaller, the EOS-1Ds Mark III achieves the same full-time ISO 100 - 1600 range (50 to 3200 in extended ISO mode) as the EOS-1Ds Mark II thanks to minimizing the gap between on-chip microlenses, reducing the space between photodiodes and microlenses, and upping the collection efficiency with exposure processing improvements.
(4) Five fps continuous shooting with a 56-shot maximum burst
The EOS-1Ds Mark III can shoot 56 frames in succession (Table 1) at a maximum speed of about 5 fps despite the massive amount of data the 21.1-megapixel images represent.
Even though it handles images almost twice the size of those of the EOS-1D Mark III, it manages to write images in the same amount of time since it supports UltraDirect Memory Access (UDMA), a new CF card specification (Compact Flash Specification Revision 4.0) that permits faster writing to CF cards.
The time required before the next photo can be taken after the internal buffer memory becomes full is less than one second for JPEG Large images (compression rate of 8) and about three seconds for RAW images.
The time necessary to clear the buffer memory after it becomes full is just under 20 seconds.
|Table 1: Benchmark file sizes and memory card capacities by image size|
(5) Fine-tunable image-recording quality and new small RAW (sRAW) option
Images are recorded in one of two formats: RAW and JPEG. The EOS-1Ds Mark III supports two sizes of RAW images: full (~21.1 megapixels per image) and sRAW (~5.2 megapixels per image), which is one-quarter the size of full RAW.
There are four JPEG sizes - Large, Middle 1, Middle 2, and Small (Table 1). The JPEG quality (compression rate) can be set independently for each image size (from 1 to 10 on the camera menu).
Also, like on the EOS-1D Mark III, a JPEG image, selected from one of the four sizes, can be recorded simultaneously with the RAW image or sRAW image.
It is also possible to set the recording method independently for the three types of recording media: CF card, SD card, and external recording media via the wireless LAN WFT-E2 accessory. The following recording method options are available:
· Standard (default/records only to specified media)
· Auto switch media
· Rec. separately
· Rec. to multiple
This setting is displayed in the top right of the image-size selection menu.
The EOS Integrated Cleaning System: an evolution in total dust elimination
The EOS Integrated Cleaning System was developed on the basic concept of ''don't make, don't collect, don't leave'' any dust in the camera. This 35mm full-frame model uses the four-stage comprehensive cleaning solution outlined below.
(1) Limit the creation of dust
When we redesigned the shutter mechanism and its raw materials for a 300,000-cycle service life, our first priority was to ensure these parts shed very little dust themselves.
(2) Limit the collection of dust on the surface of the imaging sensor
Static electricity, which is a major cause of dust accumulation, is completely discharged.
(3) Remove dust with ultrasonic vibrations
The Self Cleaning Sensor Unit (Photo 3 and Figure 1) is combined with an infrared-absorption filter directly in front of the CMOS sensor. The unit shakes off any attached dust with ultrasonic vibrations. The unit operates automatically for 3.5 seconds each time the camera is turned on or off. The cleaning operation can be run manually from the menu or it can be disabled.
|Photo 3: Self Cleaning Sensor Unit|
|Figure 1: Self Cleaning Sensor Unit Construction|
(4) Obtain and append Dust Delete Data to images/remove dust spots automatically in software
When the Self Cleaning Sensor Unit (in (3) above) cannot eliminate all the actual dust, including oily substances, from the sensor, this function maps the dust images (which are found and recorded by taking a photo of a solid white object beforehand) and adds this information to the image data. Later, the dust map is used by the included software (Digital Photo Professional Ver. 3.2) to automatically process and remove all dust spots from the image data.
Advances in basic viewfinder performance
The viewfinder optics have been completely redesigned (Figure 2 and Figure 3). This redesign has created the highest ever viewfinder magnification (maximum viewfinder coverage angle, Figure 3) in the history of EOS-1 cameras and the expansive viewing sensation that one would expect from a full-frame camera. The redesign includes a large pentaprism made from high-refraction glass (Photo 4), a large eyepiece lens with four air-spaced elements, and new super-imposition optics.
|Figure 2: Construction of the viewfinder optics|
|Figure 3: Comparison of viewfinder coverage|
|Photo 4: Large pentaprism|
The information display within the viewfinder (Figure 4) has been further enhanced with the addition of the metering mode, battery check, highlight tone priority display (ISO zeroes are smaller), and other indicators.
|Figure 4: Viewfinder coverage and information|
This month we contrasted the differences between the EOS-1Ds Mark III and the EOS-1D Mark III. Table 2 compares the main specifications of the new EOS-1Ds Mark III to the EOS-1Ds Mark II, our previous 35mm full-frame model, and the EOS-1D Mark III, our flagship model aimed at professional sports photographers and photojournalists.