0

I have to plot a full-hd video (1920-1080) made with a nikon d750 with full frame sensor for a CG and live action compositing.

1 - how can i calculate the physical size of the sensor? 2 - Is there any math formula to solve this problem? 3 - If so, does the calculation also apply to rooms with smaller sensors - crop factor (APS-C - APS-H, etc.)

So is there a standard rule to do this calculation?

The three calculations below are standard only for RED EPIC, or can they be done for other camera as well?

  • In a RED EPIC, the pixel pitch is 5.4 µm (0.0054mm) At "4K 16: 9", the number of pixels that actively captures light is 4096 px for 2304 px (4096 pixels wide).

So: Pixel pitch * Horizontal pixel count = Camera sensor width 0.0054 (px / mm) * 4096 (px) = 22.12 (mm) 0.0054 (px / mm) * 2304 (px) = 12.45 (mm)

  • Sensor width = 2 * (FocalLength * TAN (0.5 * HorzFieldOfView) / 57,296))

  • sensor width = 2 * focal * tan(angle / 2)

How do you calculate the size? I'm really confused

Michael C
  • 175,039
  • 10
  • 209
  • 561
Edward
  • 151
  • 1
  • 5
  • 3
    I'm really struggling to work out what you're trying to get at here. If you want to know the size of a sensor in a camera, just read the spec sheet. – Philip Kendall Jul 28 '17 at 09:09
  • Do you want to calculate the sensor size reverse from a picture where you know focal length and perspective or why don't you just take the size from data sheet? For system cameras you might also just take off the lens and measure the size... – Gerhardh Jul 28 '17 at 11:48
  • I just wanted to figure out if I can calculate the size of the crop with the first formula I described: 0.0054 (px / mm) * 4096 (px) = 22.12 (mm) 0.0054 (px / mm) * 2304 (px) = 12.45 (mm) – Edward Jul 28 '17 at 11:59
  • 1
    It is worth noting that the final output of many cameras does not make full use of the sensor of the camera. For example, the RED EPIC you mention shoots DCI 4k, not consumer 4K, so when using consumer 4k, some number of pixels will not be used. – AJ Henderson Jul 28 '17 at 15:23

1 Answers1

0

Unless I'm misunderstanding the question, full-frame, APS-C, APS-H define the sensor sizes? Why do you need to calculate, when a 'full frame' sensor is, by definition, 36x24mm. See http://photoseek.com/2013/compare-digital-camera-sensor-sizes-full-frame-35mm-aps-c-micro-four-thirds-1-inch-type/ for the dimensions of the specified sensor types.

If the full frame sensor is 36mm across, and the HD video resolution it captures is 1920px across, then when scaled there is an equivalent of about 53.3 pixels per millimetre horizontally (1920/36). The effective horizontal pitch should be 36/1920 = 0.01875mm (not the same as the official camera rating, because that is at full resolution)

laurencemadill
  • 2,815
  • 16
  • 24
  • So, full frame sensors do not have a crop factor and therefore the dimensions are those that are in the camera specifications. Here I find a contradiction: why then is it said that the camera makers bring the values that do not actually correspond, in this case to the real sensor? Then by following this speech you have to calculate both the size of the full frame and the smaller one. or not ? The three calculations described in me in the first question are calculations that produce a good result? I do not understand what the two numbers refer to: 53.3 and 0.01875. – Edward Jul 28 '17 at 09:48