3 ms·

Not sure how narrow the depth of field would be with the 1.4x extender and the tiny little sensors though.

• semi-extrinsic 4y ago
  It's going to be super narrow still. I tried punching this in on an online DoF calculator which has 1/4" sensors, but it only goes to 1200mm@F/45[gameboy], which is the equivalent of the 70mm@F/4[fullframe] end of this lens. Even then, focusing at something 40 ft away you have a 0.2 ft depth of field, so a background 10 ft behind your subject will be pure blur.
  • aspyct 4y ago
    That doesn't seem right. Out of focus blur is a function of focal length and aperture. The sensor size only dictates the crop. In this case, the lens widest setting with a 1.4 extender is 98mm @ f/4. On a full frame sensor, something 10ft behind a in-focus 40ft away thing would still be very recognisable. Since a crop sensor is just a crop, I don't think it would have a different effect. The 1200mm focal length equivalent only applies to the fov radius, not to the blurriness. What's your definition of "pure blur" then?