Can I use Nikon ML-L3 Remote Control to take exposures for about 10 to 15 mins with my Nikon D7000. If yes, then shall I have to keep the remote pressed during that period or whether I can leave exposure on, while pressing it once and shut exposure after 10 to 15 mins by again pressing it. Need help.
You can view the full instructions for the ML-L3 here.
I've found when taking long exposures that using a wired remote shutter release works better for me. You can operate the shutter from behind the camera and also have the ability to do a half press before releasing the shutter. You can use the viewfinder or the LCD screen in Live View to be sure of the framing and focus. For your Nikon D7000 you can use either the Nikon MC-DC2 or a generic equivalent. The wired remotes have a lock that holds the button down without having to physically hold it with your finger. I loop my wired remote around one of the adjustment knobs on my tripod so that I can let it go without it pulling on the camera.