Nikon DX vs FX

May 18, 2014

Nikon DX vs FX

Before getting into sensor formats, it is important to understand what is a sensor? To make it simpler to understand, you can consider camera sensors as a human eye. The lens of the camera essentially works like the cornea of our eyes, gathers ambient light and transmits it to our iris. The iris then expands or contracts to control the amount of light that enters our retina, which functions almost exactly like a camera sensor. Our retina is light-sensitive, meaning it can adjust its sensitivity based on the available light. If there is too much light, it decreases its sensitivity, while increases the sensitivity in a dim environment.
The sensitivity of your eyes is just like the sensitivity of the sensor, also known as “ISO” in photography. But sensitivity comes at a price – high sensitivity levels decrease image quality. This degradation of image quality is determined by the amount of “grain” or “noise” in the images, followed by loss of detail, sharpness and color in extreme levels of sensitivity.

Mirror size differences between D800 and D3100:

All digital sensor formats have been compared against 35mm film. In the case of DX format, due to the sensor being smaller than 36x24mm (size of 35mm film), the subjects appeared slightly more magnified when compared to film or Full frame sensor. This was normal for the DX format, because smaller sensor meant that a smaller area of the lens towards the center was to be used and everything else discarded. For example a DX digital camera using a 50mm lens appears to have the same view as a full frame with a 75mm (50mm X 1.5) lens.

Advantages of FX format

1. Scalability – due to the large size of the sensor, FX format provides large resolution which is of great use for landscape and fashion photographers as they need large print sizes and would therefore want more resolution.
2. Higher sensitivity and lower noise – Pixel size plays an important role in sensitivity levels of the camera, along with controlling noise levels at high ISOs. You can refer the example below and can compare the ISO performance of D800 (FX) and D3100 (DX) cameras with same camera settings.

(F8, ISO 6400):


(F2.8, ISO 6400):

3. Large dynamic range – again, bigger pixel size allows collecting more light particles, which results in larger dynamic range when compared to DX.
4. No field of view issue – with FX, forget about such things as “crop factor” and “equivalent focal length” – you get a similar field of view as if you were shooting film.
5. Lens compatibility – FX lenses are backwards compatible with DX lenses, meaning that they will work perfectly on DX bodies as well.
6. Larger and brighter viewfinder – large sensor means large mirror and pentaprism, which means a large and brighter viewfinder. Focusing with a large viewfinder is much easier, because you see more details.

Using Nikon DX Lenses on FX Cameras

Since the glass elements in a camera lens are round, lenses project a circular image onto a camera’s sensor plane. This projected image circle must be large enough to cover the rectangular sensor.
Lenses designed for Nikon DX (EF-S lenses in canon) generally project a smaller image circle because they only need to cover the smaller DX sensor. This enables a DX lens to be smaller and lighter, but also means that these lenses are not suitable, by design, for FX cameras. 


Nikon FX sensors generally are about 2 stops better than DX counterparts. The size of the sensor and pixels within the sensor is extremely important and FX shows that it is a far more capable sensor than DX when it comes to noise, dynamic range and other factors.
While a full frame DSLR provides a bit better overall quality, both have their uses. The important factor is the type of photography that you shoot and the budget that you have for your photography. Feel free to drop your queries/ comments.
Happy Clicking!


Rohan Mishra Photography- Creative Weddings and lifestyle photoshoots.