[wim]

Uhmmm... 2 things:

 

1. He means blur, not bokeh. Bokeh is about the quality of the blur, not the amount.
   
2. Equivalence is about the amount of blur already. 56 x 1.5 = 84mm Same FOV. f1.2 x 1.5 = f1.8. So, same blur.
   

And yes, if you want the same exposure time, again the crop factor. APS-C ISO 400 -> FF 400 x 1.5 x 1.5 = ISO 900. Same exposure time.

 

He does indeed confuse blur and bokeh.

 

What you are saying about exposure time I do not understand. For a given amount of time, at the same iso and same aperture, exposure time is always the same, regardless of camera used.

 

If you are talking about noise, you may be right about the specific iso value, provided the sensor tech of the cameras compared is similar.

 

Smaller sensor tech, smaller within reason, is much more rapidly advancing than the larger sensor tech, and it appears to be resulting in noise leves which are less than before. F.e., the latest Olympus 20 MP sensors are a stop better noise wise than the older 16 MP sensors, despite having 25 % more pixels.

 

Apart from that, IMO it is horses for courses. Don't shoot over 3200 iso with the previous incarnations, and not over 6400 iso with the newer ones, and you don't see the noise at 45 cm x 60 cm prints unless you use a magnifier, or larger even when processed properly.

 

Kind regards, Wim