I am trying to "misuse" Blender as a research tool for a camera setup I want to simulate.

It uses a specific combination of Sensor (1/3") and Lens (16mm), which I want to simulate in a realistic way. Since the testing subject is only a small circle that does only cover a small part of the sensor, I want to reduce the sensor size as much as possible to save memory and rendering time.

The setting "Size" (see screenshot below) is limited to a lowest value of 1 mm, since there are not many camera sensors in real life that are this small. However, I want to reduce the virtual camera sensor size to a lower value to decrease the FOV without altering the behaviour of the lens.

  1. Can I somehow disregard the lower boundary, which seems to be hard-coded?
  2. Alternatively, is there another way to simulate a narrower FOV while keeping all optical characteristics the same? E.g. I can not change the focal length od FOV setting, because then the DOF would not represent the real thing anymore since the aperture is f/1.8 and then would also get bigger (I could scale the f-stop appropriately, but isn't there an easier way?)

Thank you in advance!


  • 1
    $\begingroup$ Hi :). Lowering sensor size works exactly like cropping the final image. So instead you can render it with a higher resolution, and crop the image in post. The result will be the same, and you'll avoid messing with the camera parameters :) $\endgroup$ Jan 18 at 11:09
  • $\begingroup$ Thank you very much; indeed i tried this, but this results in giant images that do not contain any information; I would like to have the smaller FOV too which I dont get by adjusting the resolution. The main problem is that the blank parts of the frames also take long to render. I think there was a possibility to "channel" rays in blender such that this problem is avoided, I did not find this through internet research though. $\endgroup$
    – Pidrittel
    Jan 18 at 11:58
  • 3
    $\begingroup$ I think it's a good idea to set the render region. $\endgroup$
    – tetii
    Jan 18 at 13:10

1 Answer 1


Possibilities I found so far:

  1. Rescale Focal Length and appropriately also rescale Aperture value by the same factor (e.g. focal length 16mm --> 64mm, f/1.8 --> f/7.2)
  2. Crop the final image with higher resolution (in my case, the resolution would have to be too high to render in appropriate timeframe)
  3. As suggested by user tetii: set smaller render region, even in combination with 2): works. In my case, I used this Addon to even be capable to varying the render region by frame.

I now see that this really is a pretty special use case, but those three options can do the trick. Still, I think the sensor size should not be limited to a minimum of 1 mm just because smaller real sensors do not exist. Why limit the sizes to "physically possible" sizes? Take a photo if you want to be limited by reality. :) Anyway, thanks for the suggestions!


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