Orion 1 as my friend says it really depends on the display you are using.On light a/c with an OBI/CDI these tend to be 5 dot displays where half scale deflection is 2 1/2 dots.IR test limits are half scale deflection.On most EFIS equipment is 2 dot.
Rule is "MORE THAN HALF SCALE DEFLECTION-THROW AWAY THE APPROACH"
cheers AUTOTHROTTLE