The SX130IS sensor is (6.17 x 4.55 mm), while
the A540 sensor is (5.76mm x 4.29mm).
In addition, the a540 was 6.0 mp, 4X optical zoom: the SX130IS rates 12.1 mp, 12x optical zoom.
The newer camera should blow the older one out of the water in every way, yet it doesn’t.
Ah well, it’s still a very good camera. Better than anything I owned 10 years ago.