oh no.. I thought 50mm would be an ideal one for portrait.

both A and S is almost the same

A mode = adjust your aperture and it will auto set a shuttle speed for u

S mode = adjust your shuttle and it will set aperture for u

landscape need very low aperture to make sure everything is clear and sharp and even get star effect at nights
(if you are new = high aperture means lower F like f5.6 - 1.2) ( low aperture means HIgher F like f10 -22)

Lower aperture in low lights will make shuttle delay time to capture more lights which is impossible to handhold shooting.

A tripod is a must for landscape shooting

U could skip the tripod but u must make sure shuttle is good enough for u to shoot without delay from shuttle.

any lower aperture setting will make higher delays on shuttle .

Landscape is very fun with tripod and a wired remote

1000d or d3000 ? i tried d3000 before not bad .