# The Camera Field of View thing

Take a look to this image:

It has the numbers I would expect. If the distance from the point of view to the lens goes larger (50 is the max in the image above) the fied of view reduces to 5 degrees. If the point of view nears the lens (1.78mm is the min) the field of view wides to 130 degrees.

Now: In blender we have a field of view of 14 degrees that are 130 mm. A field of view of 50degrees is 34mm.
In the above image 14 degrees would be something like 20mm and 50 degrees would be like 5mm

So: why are blender camera mm like 6x of what you see in the above image? Is blender camera correct or wrong?

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Camera

Anyone knows of a similar image as the one I posted for the camera that blender uses. Perhaps my image is for modern cameras and blender is using the camera data of the time of Charles Chaplin?

In the Tron 1 movie a guy talks about the extraordinary camera they used that allow them go up the 50mm you see in the image in first post to a value like 60 I think he said. That permitted very close first planes in the scene where they talk in flint upper room office above the game machines below. I didn’t knew there was that 50mm barrier that they had to break with a very expensive camera, because you go to blender and you have 130 degrees or whatever. But if this blender value is 6x then using 130 is like using 23 or so. 50 would be like using 300 I think.

Or perhaps blender is using some real movie camera and it is completely different than the video camera data I posted?

Another one: (exactly like the one in first post and completely different than blender again)

In the Camera presets you choose for example the “Full frame 35mm Film” and it sets a Field of View of 15.729 degrees and if you change the Field of View to Milimeters it shows 130.309. In the images above 15 degrees would be like 25mm. So: Why blender uses such a 6x number for the mm ???

The focal length required for a given angle of view scales with the sensor size; for example, for a 90 degree viewing angle, the focal length should be half the sensor size. The numbers you have shown are for video cameras with a small sensor: the sizes quoted are 1/3" (8mm) and 1/2" (13mm), and the data given imply that the active width of the sensors is only about three-quarters of that. Most of the Blender presets are for active sensor widths of ~20 mm to 36 mm.

Best wishes,
Matthew

Thanks. Understood at last.

The field of view depends on both the focal length and sensor width. Those charts are for a 1/3" type sensor which is approx 4.8mm wide and not 36mm. If you change the sensor width to 4.8mm and set the focal length to 4mm, you will come up with 61deg which is close to what the charts show.

Edit: eh… I type too slow…

I didn’t thought of changing the sensor size. Will try too!