Why Nikon CX sensor so small? (size comparison)

September 21, 2011

In this article I want to put my mind on the decision of Nikon to use a CX-format sensor, which its size is smaller than the APS-C and even the Micro Four Thirds one. Some people (including me) were surprised to see that Nikon has chosen to use a sensor that is smaller than the Micro 4/3. Many of us know that their is a direct implication on image quality, especially with the amount of noise in high-ISO sensitivity level.

Before I continue the discussion about what are the implications of using the CX sensor vs larger camera sensors, let’s see a sensor size comparison paradigm that illustrates the difference in sensor sizes, including APS-C, Micro Four Thirds, CX (the one used with Nikon 1 mirrorless cameras, 1/1.7-inch and 1/2.3-inch):

Sensor size comparison pardigram

APS-C, Micro Four Thirds, CX, 1/1.7-inch and 1/2.3-inch sensor size comparison

Nikon FX = Full Frame (35mm)
Nikon DX = APS-C
Nikon CX = 1-inch (Nikon 1 Mirrorless cameras)

The above image illustrated the differences between sensor sizes. Yu can see that the CX-type sensor used in the Nikon 1 J1 and V1 cameras is much smaller than the M43 one, but four times larger than the 1/2.3-inch one.

There are cons and pros for both large and small sensors. Let’s go over the advantages of each one.


Advantages of Small sensors

  1. Ability to manufacture relatively cheaper, smaller and lighter cameras
  2. Create cheaper, smaller and lighter lenses due to the smaller projected imaeg circle
  3. Can lower sensor manufacture price (depends on the technology used)
  4. Deeper Depth of Field (DOF) for the same equiv. FOV and f-stop , Good for Macro and Landscape shots
  5. Higher focal length multiplier (2.7x in the case of the CX), also means longer zoom but in more compact lenses (see sectino 2) – magnified angle of view
  6. Sharper images due to the fac that most lenses are sharper in the center (more evident in 35mm lenses used on smaller size sensors)
  7. Easier to manufacture wide lenses


Advantages of Large sensors

  1. Ability to get much more shallow Depth of Field – great for portraits
  2. Lower focal length multiplier (1x on 35mm, 2x on M43), less magnified angle of view – great for wide angle shots
  3. Better low light performance, less noise in high-ISO
  4. Better for lage prints, requires less magnification
  5. Better color accuracy and image quality in general


Of course the disadvantages works the other way around, but mostly are related to the ability of the sensor diodes to absorb more light photons.  A larger sensor will (in almost all cases) will results in better image quality, especially in high-ISO.

Now, Nikon 1 CX sensor carries a focal length multiplier of 2.7x, compared to 2x on the Micro43. The sensor’s dimension on the Nikon 1 J1 and V1 equals to 13.2 x 8.8 mm (1-inch). In image quality terms, that means that in practice, Nikon 1 mirrorless cameras will (most probably) won’t be able to give the same high-ISO performance compared to Sony NEX and Micro Four Thirds cameras (ie. Samsung, Olympus, Panasonic).

The question that many people ask themselves is why Nikon has decided to use a small sensor and not use an APS-C sensor like Sony NEX mirrorless cameras (ie. Sony NEX-7 and NEX-5N)?According to leading camera review websites and analysts in the field of digital photography, Nikon didn’t want the Nikon 1 cameras to overlap / clash with its DSLR cameras, which can result in decrease in sells.

Some people think that Nikon has actually done a very smart marketing move. Photographers who search for an advanced camera  can choose from either Nikon’s high-end compacts (ie. Nikon P300),  Nikon 1 Mirrorless camera or buy a digital SLR camera.

Those are distinct camera types both in terms of of price, performance and the features that each camera offers to its respectable owners.


Has Nikon forgotten about the competition in the mirrorless market?

Even if the above is correct, there is the issue of competition. Nikon is not alone in this market. In fact, it’s fashionably late entering the mirrorless market. Releasing a new camera lineup doesn’t promise Nikon success.In fact, some will prefer investing in a Sony NEX camera due to its larger sensor and better image quality in high-ISO. That already proved to hurt the sells of DSLR cameras worldwide.

I also think that Nikon assumes that those who purchase a mirrorless camera don’t give that much attention to the image quality in high-ISO. If it’s not true, how come they release new cameras with a relatively small sensor?

This will be surely tested in 2011/2012 and we’ll see how the market adopts Nikon’s new mirrorless cameras and interchangeable lens lineup.


What’s Your Opinion?

I am opening this discussion in order to hear your opinion about that “issue”. Do you think that Nikon has made a smart move releasing Nikon 1 J1 and V1 mirrorless cameras with sensors smaller than APS-C and smaller than the Micro Four Thirds?