The 50 f1.7 has such great appealing because it's about the cheapest fast prime that you can get.
totally agree! but of course that's not the only appeal, i find 50mm on aps-c convenient for portrait shots in a group setting in a small event. i use 28mm aps-c if i want portraits of friends since we tend to be physically much closer together
If you're excited about the SSM on these new lenses, remind yourself that they're most likely the consumer graded version, micro-motor, not the true ring-motor like those found on the G or CZ. Micro-motor is certainly quieter than screw-in counterpart, but not necessarily faster. I highly doubt those new things will be faster the A700 motor.
Not too sure about this though.
As far as I remember, SSM is sony's tradename/marketing name for their ultrasonic motor, same as USM and SWM or SWD or SDM. they work on the same principle of using friction of the oscillating stator to drive a rotational motion in the ring rotor.
As for micro-motor, i don't think it is a appropriate definition for the working principle of a motor. directly interpreted, it is just a small motor. the ultrasonic motor can be considered a micro-motor. and so can a small dc coil motor be considered micromotor.
if your in-camera screw driven motor is small enough, you can call it a micromotor too!
And after writing these, i realized i made a wrong assumption. i assumed that these lenses that Sony displayed had SSM in them because the AF/MF switch was on them. Walas, for all i know it could just be a small dc coil motor (a.k.a. micro-motor) on them instead! Damn...
But in any case, there is no guarantee that SSM is faster than the A700 motor. However, SSMs have much higher potential to be faster, quieter, more accurate, more precise. Speccing the components in a SSM differently (such as the control circuit, the oscillator, the coating, the material etc...) would result in different performance of a SSM.
So, if Sony does give me a SSM in the DT50mm, i would be excited about its potential to be faster and more accurate. And be damned if Sony gives me a low-specced SSM
