Outdoor University Graduation Portrait and Family Photography Session

Hi, I need professional photoshoot in London for my family graduation photo. I would like to have it done in outdoors somewhere in London, preferably Big Ben Here is the details :- 1) Individual picture of me and my sister ( 2 graduates ) 2) Family session 3) Time : 3 pm or 6pm , Date : Thurs , 20/07/2017 or Mon, 24/07/2017 ( We haven't finalised yet but please free to tell us which day or time can you make it ) We are thinking to take under the sunset if possible. 4) Photo shooting takes around 3 - 4 hrs Please advise how many photos + editing could you provide us Thanks.