# What are the units for camera shift?

I'm having trouble making sense of the units of a camera lens shift. It ranges from -2,2, defaulting to 0, but it doesn't seem to be in scene units, nor does it seem to be in radians.

Anyone have an idea what the values represent?

It seems to be in percentage or fraction of the render size (in pixels).

That means that a lens shift of 1 shifts the camera exactly one frame unit in a certain direction, making it frame exactly outside the previous default framed area.

This is measured however in relation to the largest dimension of the rendered frame size. So lets say you are rendering in Full HD, that is 1920 x 1080 pixel image; a frame shift if 1 unit will shift exactly 1920 pixels in any direction, that is up/down/left/right.

This may seem obvious while shifting sideways towards the X axis, but might seem random while shifting in the Y axis.

• Very insightful! Accepted. I was only tweaking the y-shift, so it did indeed seem random. Thank you. – user48206 Jul 20 '16 at 4:10
• @user48206, Duarte, this is not random : have a look at the camera shape from outside in ortho view (the 3D View ortho, not the camera ortho) – lemon Jul 20 '16 at 5:15
• Yes, I know it's not random as stated in my answer, I meant it might seem random while controlled from the smallest render dimension, since 1 unit will not correspond to exactly one frame size shift. – Duarte Farrajota Ramos Jul 20 '16 at 13:48

For the Calculation of the smaller Dimension with the Resolution of 1920x1080. If the larger Dimension 1920 has a Value of 1.0, than the Value to Shift the Camera along the full smaller Dimension of 1080 is:

1080px/1920px = 0.5625