@pranav, amlan and gen ...thanks all
Pranav exif says flash not fired coz I triggered the flash through flash triggers ....you can see that the trigger is attached under the flash on flash holder...now what you have to do is tilt the umbrella's front side towards yourself and fire the flash through the umbrella..soo the diffused light will be very unidirectional and fell on small area...
If i would have used it backwards thats I stand behind the flash then the inverted umbrella would have given much more light and whole face would have properly lit
background as I said in that post..I bought a black wrinklefree BG (check spoiler) it gives pitch black BG
@gen some of ur questions I already explained here
and umbrella can be used anywhere...I saw lots of youtube video to learn and undestand ...you guys can check portrait with single flash setup on youtube.
@nac The lens is huge...and my hands are still paining after carrying it for 2 hrs in a garden ...and sadly all my pics came crappy...no use of internet advices...will have to find a way my self...will go tomorrow again..lens is 3 years old