3 ms·

Isn't that the expected depth of field you'd get from f/2.5?

• OJFord 4y ago
  That's what I'm asking, without even being certain if it's f/x or y mm that affects that.
  • andybak 4y ago
    Amongst other things, the f number affects the depth of field (how much of the image is in focus. A low number (f/1.6 is fairly low. f22 is fairly high) means that only the object you focused on will be sharp and anything nearer or further away will become blurry. This is great for portaits for example as it draws attention to the person. (f is the aperture and also affects the amount of light. You can shoot with a lower shutter speed if you have a wide aperture/low f number) The "mm" number is the amount you're zoomed in. Wide is a low number, telephoto from a distance is a high number. But blur can come from other things. Cheap lenses, unsteady hands or moving subjects. Depth of field is just one type of blur.
• SAI_Peregrinus 4y ago
  No. The "depth of field" for a lens parallel to the sensor is a space between two planes, so you'd expect it to be clear all the way across the image but blur closer and further from the sensor (up and down the image). This blurs out to all the sides, it's due to spherical abberation from inappropriate glass (more suited to telescopes where only the center of the image circle matters).