lightmeter and apperture

[sudarsansframe]

1. Are lightmeter n apperture setting are for same purpose? because both point the exposure or the brightness, if i'm not right please explain....

2. how is shutter speed related to apperture.... how does it works ? what and how the difference can be noticed??

3. which one is better 70-300mm tamron lens or sigma lens? what are the pros n cons over each other and pls comment on the performances of these lenses...

[OsmosisStudios]

1: Aperture is a factor in determining exposure, your light meter shows you the level of exposure you're currently sitting at. This exposure is a combination of aperture, shutter speed and ISO. Adjusting any one of these will affect your light meter.

2: Shutter speed is another factor in exposure (as mentioned above). Slower shutter speeds can cause blurring (intentional and not) while faster shutter speeds freeze action.

3: That depends greatly on individual lenses. To be honest, at its current price point, then Nikon 70-300 VR is fantastic.