inside a hdb flat...or a typical SG apartment...unless ur room is facing the morning sun...f/2.8 won't suffice. u will still need flash. and the 24-70 is really heavy and bulky u noe? u haf gotta rent one for a day. i carried it for 3 days and on the 2nd day only, i was already sick of it. yes, nice images (17-55 nicer though) but its heavy and bulky. everywhere i go ppl give me that weird look. well i guess in the age of the internet and fast widespread mediums, ppl are very sensitive to ppl with huge cameras with huge lenses. anyway i dun tink u wanna get the 24-70 for a family outing too, cuz its really troublesome. the weight and size makes it really irritating. can u imagine going for a family outing with a rifle in one hand? for a few hours its ok, it will feel weird but its ok. but as the time goes by, it will eat u up and irritate the hell out of u. your right arm and hand will ache. thats wad put me off getting lenses that are big and to exploring primes. in the end i settled for the 50 f/1.4 and im really glad i did. image quality on par with 24-70 or better - in my opinion. i think the ideal walkabout for 1.6x is still the 15-85. may not be L-rated but it has UD and aspherical glasses. so its almost as sharp and infact better than some Ls like the 17-40L. the build is solid, pretty compact, light but you know its there...perfect for consumers who just wants a general purpose lens. but if u die die want a zoom with f/2.8, den u really haf to bear with the size and weight. =/