Hello first first I recommended the descriptions
4.0 megapixel CCD
4x ( 35-140mm equiv.) zoom lens
Manual, semi automatic and fully automatic exposure
20 exposure modes
New 'hold' function
Zoom flash
9-point AiAF focus
Optional underwater housing, external flashgun and add-on lenses
AA battery power
the PowerShot A520 is the replacement for the PowerShot A85, and continues the line of best-selling budget models that goes right back to early 2001 with the A10 and A20. The changes are evolutionary rather than revolutionary; a reduction in size and weight ( it's 13% smaller and 20% lighter) , the inclusion of a new four times optical zoom lens ( the A85 had a three times) , zoom-linked flash, a shift from CompactFlash to SD card for storage and a drop to two AA batteries from four.