Understanding the Nikon D200 Multi Cam 1000 AF Module
The Nikon D200 is proving to be one of the most popular digital SLR cameras ever produced by Nikon, and for good reason. Within the Nikon D200’s smaller-sized body lives the heart of a true professional camera. Since it contains most of the feature sets of Nikons costing thousands more, the Nikon D200 is a complex and effective image maker as long as you understand the technology that makes it work.
Nikon D200 Digital SLR
One of the more complex parts of a camera’s operating system is the Autofocus (AF) subsystem. The Multi-CAM 1000 AF system was released for the first time in the Nikon D200, so we’ll use that camera and its manual as the base for this article.
To really maximize the use of the Multi-CAM 1000, it’s important that new users spend some time with articles like these (and with the camera’s manual) until they have a good grasp of how the AF system works. The initial time spent studying will result in professional quality images later.
The Multi-CAM 1000 AF system is not that hard to understand so why not get your user’s manual, and your camera, and let’s go over the autofocus modes in detail.
What is Multi-CAM 1000 Autofocus?
It’s a significantly improved version of the Multi-CAM 900 autofocus module found in the Nikon D100, D70, and D50 digital SLR (DSLR) cameras. Where the Multi-CAM 900 was limited to Single Area, Dynamic Area, and Dynamic Area with Closest Subject Priority modes, the Multi-CAM 1000 adds another AF mode called Group Dynamic. This mode gives you finer control over things like sports photography, macro focusing, and selective area AF.
While the Multi-CAM 900 had five AF sensors, the Multi-CAM 1000 gives us 11. It is very similar to the 11-sensor arrangement in the flagship Nikon D2x Multi-CAM 2000 system. So, you can expect professional-level performance from Multi-CAM 1000 in the D200.
Why is it called Multi-CAM 1000? The number 1000 represents the approximate number of CCD contrast-sensing elements in the autofocus system. With so many elements, it will autofocus in low to high light levels and at high speeds.
A unique feature of the Multi-CAM 1000 in the Nikon D200 is the ability to combine the 11 sensors into a 7-AF areas wide-array arrangement. This gives you the ability to better follow moving subjects like flying birds, race cars, or airplanes. We’ll discuss the Focus Zone Selection (7-AF areas array) in a later section of this article.
Now, let’s consider the various parts of the Multi-CAM 1000 AF system, and how they work.
What is Focus Lock, and How Does it Work?
Let’s start our exploration by looking at some basic information.
One question often asked is, “What does it mean to lock focus?” That’s a great question since it involves how the camera decides when a picture can be taken, and what AF modes you’ll find most useful for your particular needs.
If a subject is moving, the camera will use two technologies to track it. They’re called Predictive Focus Tracking® and Focus Tracking with Lock-On®.
We’ll talk more about them in a later section.
Using these technologies, the camera detects that the subject is moving in the few milliseconds that autofocus is in action. According to whether it’s in “single-focus” AF-S mode (Single Servo AF) or “constant-focus” AF-C mode (Continuous Servo AF) two distinct events will occur.
Single Servo AF: In this case, the autofocus system sees subject movement and does not “lock” the focus until the subject stops moving. When the subject stops the focus “locks.” Once this lock takes place, the little round green light comes on in the viewfinder, and autofocus activity ceases. You must reactivate autofocus by lifting your finger and reapplying pressure. The focus is truly locked and will not try to follow your subject unless you refocus. To follow a moving subject requires you to tap the shutter button as the subject moves.
Continuous Servo AF: When using this mode the autofocus never “locks” at all. It does “lock on” to your subject though, and tracks it until you take a picture.
So, “Focus Lock” is simply the camera making a decision, based on the fact that it has acquired a subject and is ready for taking a picture.
Once the camera decides that it is ready, something else comes into play. It will capture images with two levels of focus accuracy, according to how you have the AF “priority” set in Custom Settings a1 and a2. The two priorities are “Focus” or “Release.” We’ll discuss these in the next section.