NIKON D7000 FEATURES (continued).
2016 pixel RGB sensor for metering:
After 14 years of using their 1005 segment RGB meter (first seen in the F5), Nikon released a newly developed 2016 segment metering system in the D7000. Since the new metering module has more than twice the number of RGB segments of its predecessor, and because it’s combined with the new (presumably more powerful) EXPEED 2 processor, it certainly seems like Nikon’s new metering system is a step forward. I never took the camera out of manual (M) mode, and used manually controlled Ikelite DS160 strobes (no TTL), so I didn’t actually test this system underwater.
100-6400 ISO range (expandable to 25600 equivalent):
The first thing I did when I turned on the D7000 was shoot at high ISOs to compare with my D300. To say that I was shocked is an understatement – flabbergasted is more like it. Even though the D7000’s sensor has 25% more pixels than the D300 over the same area, it exhibits significantly less noise at high ISOs. Equally surprising is how well this sensor compares to the D700’s FX sensor. I don’t have a D700 to test against, but if merit is given to the DXO Mark tests, then the noise levels of the D7000 are only one stop behind it… with a sensor having 50% less area AND 25% more pixels!
This is an incredible step forward in sensor technology. It’s certainly going to be interesting to see the noise levels that the next generation FX sensors produce using this same technology – I’m sure we’ll see soon enough!
I arrived in Dominica on schedule, but my bags didn’t make it with me. All of my strobes were in those bags, but I did have the D7000 housing, Aquatica’s 9.25” Megadome, and my trusty Magic Filters, so I was stuck shooting with ambient light day after day until my bags arrived. This gave me a chance to play with the camera’s low light capabilities, and I was very pleasantly surprised time and time again. Finally, a Nikon DX camera with a usable ISO range!
As you can see from the above comparison, noise increases incrementally with ISO. The level of noise that one considers “too much” is a highly subjective matter, depending mainly on personal preference and an image’s intended use.
I enter a lot of photo contests, and print 12” x 18” images for friends and family regularly, and I’d feel comfortable doing both with images shot at up to ISO 3200-6400. If you’re only publishing images online, then the entire range is very usable… when viewed at screen resolution, the full ISO 100 shot above is only marginally cleaner than the ISO 12800 shot!
Multi-cam 4800DX autofocus sensor:
Another new feature being debuted in the D7000 is Nikon’s Multi-CAM 4800DX autofocus module. It has 39 focus points (9 of which are the more accurate cross-type sensors), and is capable of more accurate 3D tracking than previous models, when combined with the 2016-segment RGB metering module and EXPEED 2 processor. I’ve done a number of very unscientific focus tests between the D300 and D7000, and it seems to me that the D7000 wins every time in terms of speed and low contrast performance. The edge that the D300’s Multi-CAM 3500DX autofocus system has is 12 more focus points (6 more cross-type) spread over a larger portion of the frame.
An autofocus mode on the D300 that I hadn’t given a chance until now was its AF-C 3D-tracking system. This mode is also present on the D7000, but is now backed by a more powerful RGB metering system, so is presumably more accurate. The system recognizes the colour of the subject of focus, and will track it through the focus area. This simplifies the composing of images, since it eliminates the need to manually position the focus point – it just follows your subject, provided that it’s distinct enough relative to its background.
I usually only use the AF-S servo with a single focus point placed where I want it, but I now found myself using a combination of the AF-C servo with this 3D-tracking mode for shooting mid-range zoom, and macro/super macro shots. When I wanted to fix the plane of focus, I simply held down the AF-L button and then rocked the camera back and forth for fine-tuning.
Less notable is the camera’s AF-A (Auto-autofocus) mode, which decides, based on the subject’s movement (or lack of it), whether AF-S or AF-C is to be used, and sticks with that servo mode until the shutter is fully-depressed or released. This seems good - in theory - but after using it for less than 5 minutes, I got frustrated and switched out of it and never re-visited that mode. Equally useless to me is the “Auto Area AF” focus mode, which lets the camera decide which focus point should be used. This gives you no control whatsoever over what is in focus.
14-bit RAW images:
Like the D300s, D700, D3 and other high-end bodies, the D7000 can record RAW files in either 12- or 14-bit format – file sizes of the latter being 20% larger than the former. Here’s a little background info that will help you understand what these formats really mean.
A sensor’s photosites actually record grayscale data, rather than RGB as you might expect. Each photosite has a colour filter that allows either red, blue, or green light to pass through, and the intensity of this light is converted from an analog signal to a simple numerical value. Once data from the entire sensor is collected, the camera’s image processor uses data from adjacent photosites to interpolate a full colour RGB image – a process known as “demosaicing”.
The “bit-depth” of a sensor indicates the range of possible values for the recorded intensity at every photosite. 12-bit sensors have a range of 4096 values (that’s 2 to the 12th power), and 14-bit sensors have a range of 16384 values (2 to the 14th power) – that’s 4 times the range of values. This means that tonal gradients can be recorded more smoothly, fine details can be recorded more accurately, and highlight/shadow areas will contain more information for potent restoration. However, contrary to what some believe, dynamic range is not affected by bit depth, since it is related to the light sensitivity of the sensor, rather than how many levels each pixel is divided into.