F40fd battery life is 300 shot only while F31fd is 580 Shoot

F31fd 92.7 x 56.7 x 27.8 mm (3.6 x 2.2 x 1.1 in) 6 megapixel 1/1.7" Super CCD

F40fd 95.7 x 59.0 x 23.3mm (3.8 x 2.3 x 0.9 in) 8 megapixel 1/1.6" Super CCD

but both is using Super CCD HR VI and Fujifilm's Real Photo Processor II with FD technology , Weight is the same

but best things shld be F40fd support SD .

F40fd equip with a bigger Super CCD ,would it make the photo quality better ? guess without testing ,we wouldnt knw the result