Initially, the image brightness of the live view of my Nikon D3200 keeps on changing when the shutter speed or aperture or ISO is changed in Manual mode. I played around with some settings and now, I find that the brightness of the live view doesnt change at all. It is displaying in the same way as it is seen in the view finder. Change of shutter/aperture/ISO now has no effect in the live view mode. Somebody please tell me how to restore to the previous setting. Thanks.