Canon EOS 1D X Mark III vs Canon EOS 1D Mark IV

This is a full comparison between the cameras Canon EOS 1D X Mark III and Canon EOS 1D Mark IV. We compare them by looking at the categories you see below.

Canon EOS 1D X Mark III

Canon EOS 1D Mark IV

Manufacturing

These cameras are both manufactured by Canon.

Canon EOS 1D X Mark III were released 2020 and Canon EOS 1D Mark IV was released 2009. That is a 11 years difference. In tech, this period can be of interest since technology is always improving, etc.

Camera	Released
Canon EOS 1D X Mark III	2020
Canon EOS 1D Mark IV	2009

Type of camera

Both these cameras are DSLR cameras. No difference there.

Sensors / crop factor

These cameras have different sensors. Canon EOS 1D X Mark III has a "Canon Full Frame"-sensor while Canon EOS 1D Mark IV has a "Canon APS-H"-sensor, and their difference in sensors will also affect the crop factor and experience focal length. See the table below.

Camera	Focal length, 50mm f/1.8 **
Canon EOS 1D X Mark III	50 mm Full-frame sensor No crop factor/focal length multiplier
Canon EOS 1D Mark IV	65 mm Canon APS-H sensor Crop factor/focal length multiplier by * 1.3

** Experienced focal length when using a lens such as a common "50mm f/1.8"

Learn more about crop factor and focal length multiplier here:
Camera selection can affect the focal length (Canon)

Resolution

Canon EOS 1D X Mark III has a 20 MP (Megapixels) resolution while Canon EOS 1D Mark IV has 16,1 MP. If we break down this in more detail this is the data behind the numbers:

Camera	Megapixels
Canon EOS 1D X Mark III	20 MP 19961856 pixels 5472 x 3648
Canon EOS 1D Mark IV	16,1 MP 15980544 pixels 4896 x 3264

Canon EOS 1D X Mark III has a 25 % larger resolution than Canon EOS 1D Mark IV. This could give you more details in the picture but also a possibility to crop more in the pictures, afterward while editing the pictures, if needed that is.

ISO range

Canon EOS 1D Mark IV has a larger ISO-range than Canon EOS 1D X Mark III. Canon EOS 1D Mark IV has an ISO range that stretches from 50 to 102400 while Canon EOS 1D X Mark III has 100 to 102400.

Camera	ISO Range
Canon EOS 1D X Mark III	100-102400
Canon EOS 1D Mark IV	50-102400

Autofocus and lens compatibility

Both of these cameras have a built-in autofocus motor. Some lenses, that support autofocus, do not have an autofocus motor of their own but this won't cause any problems with these two cameras.

Here is a complete overview of which lenses work with each camera:
Lens compatibility chart for Canon EOS 1D X Mark III
Lens compatibility chart for Canon EOS 1D Mark IV

Pictures per second

Depending on what you are shooting the FPS, or frames/pictures per second, can definitely be of interest. Canon EOS 1D X Mark III can shoot up to 20 pictures per seconds and Canon EOS 1D Mark IV can shoot up to 10 pictures per seconds.

Camera	FPS (Frames per second)
Canon EOS 1D X Mark III	20
Canon EOS 1D Mark IV	10

Ability to record movies

It is becoming more and more popular to record movies with digital cameras.

In this case, both Canon EOS 1D X Mark III and Canon EOS 1D Mark IV can shoot movies.

Weight

The weight of the camera can be an extremely important factor, especially if the camera is about to be used, or carried around, for several hours at a time.

Canon EOS 1D X Mark III weighs 1440 gr (equal to 3.17 lb) which is 17% heavier than Canon EOS 1D Mark IV and its 1230 gr (or 2.71 lb).

Camera	Weight
Canon EOS 1D X Mark III	1440 gr 3.17 lb
Canon EOS 1D Mark IV	1230 gr 2.71 lb