SteadyShot - focal length not in supported list

[subtilior]

I have an OM 135mm lens and 2x tele-converter, giving me a lens of 270mm focal length.  The manual focal length settings available in camera jump from 250mm to 300mm.  Should I choose the higher or lower focal length to get the best results at 270mm?

I have asked Sony, but they were of little help.

[michelb]

270mm divided by 250 = 1.08 so you are off by 8% or 20mm

270mm divided by 300 = 0.90 so you are off 10% or 30mm

 

IBIS needs to work to the closest focal length possible.

[Username]

270mm divided by 250 = 1.08 so you are off by 8% or 20mm

270mm divided by 300 = 0.90 so you are off 10% or 30mm

 

IBIS needs to work to the closest focal length possible.

   

No no no no noooo .... NO ! .... there's no math involved. 

   

Percentage error is unimportant. If the higher FL were 5%

error and the lower FL were 12% error you still ALWAYS

select the lower FL. 

   

A lower FL costs you a slight bit of benefit, but a higher FL 

results in over-activity by the IBIS mechanism, leading to 

increased motion blur, created by the IBIS itself.   

   

For instance, if using a "dumb" zoom, set the IBIS for the 

short end if you're working in a crazy hurry, and just take 

into account that IBIS is not at full benefit as you zoom to 

longer FLs. Acoarst if working more leisurely, you set the 

proper FL every time you zoom to a new FL. Sounds like 

a PITA but is still quicker than swapping primes, and less 

risk of dirt entering thru the lens mount.