Tech Friday: Which size sensor should I choose?

Nikon makes two size sensors, the DX which is represented by the red line above in the Ken Rockwell sample image, (thanks Ken, great illustration!). The full area represents the size of piece of 35mm film which Nikon calls the FX sensor. Canon has a very similar system. Any other camera manufacturers that offer 35mm size sensor follow these same basic systems. The question is which is best for me? Well obviously the key question is who is “me”. Let me give you some ideas about what the relative advantages are of each.

First the Full FX size sensor is larger and therefore the individual pixels can be larger. The larger the pixel the less it has to be amped up for higher ISO, and that equals lower noise at higher ISO settings. Because the cost to manufacturer larger sensors is much higher, the cost of the camera with an FX sensor will naturally be higher. With FX sensors the lenses will be the actual marked focal length, for instance a 50mm lens is actually a 50mm lens. Because the sensor is larger, the entire viewing system is as well. This means FX sensored cameras will have larger, brighter viewfinders.

The DX size sensor gives an mage that is cropped down to approx. 66% of the FX sensored image.
Lenses used on a DX sensored camera make the lenses behave as if they were 1.5X longer in focal length. Now a 50mm lens on a DX sensored camera is still a 50mm lens, however the image it yields look like it was shot with a 75mm lens in terms of cropping. So one great advantage to the DX sensored cameras is that your long lenses give results of lenses 1.5 times longer. Because the sensor pixels are smaller, they do not have quite as good performance at very high ISO settings.
The DX sensor is less expensive to make and therefore the cameras can cost less. The lenses can also be smaller and nicer for travel where weight and size matter.

So for many photographers I advise owning both. No not because Nikon wants me to sell more cameras, but because you make your lenses have greater range, and have cameras that take advantage of both sizes of sensors.

In all but the most extreme photographic situations I doubt you could tell the difference between the two!

Enjoy your weekend………

Blessings,

the pilgrim