Movement

How fast to stop it, and how slow to smear it.

To freeze it · sharp enough

1/200s

The setting on the dial. The maths says 1/170s, and this is the next one up.

35mm · 1/200s

To blur it · clearly moving

1/8s

Track the subject through the frame and fire — it stays sharp, everything behind it runs. Continuous drive, and keep turning after the shutter closes.

Leave empty to use the subject above.
metres
mm
How sharp is sharp

What you will accept, said out loud rather than hidden in the number.

Sharp here means the same as it does in depth of field — pixel-sharp at a normal print size — so the freeze speeds come out faster than the usual advice. “1/2000 for birds in flight” is what photographers accept, not what is sharp; the tolerance setting is where you make that trade on purpose. The discounts for a subject moving diagonally or towards you are the rule of thumb, not optics: nothing comes straight at you for a whole exposure.