With whatever ancestral information you have, enter this into the Search All Records form in Ancestry at:
Tick the Photo's and Maps Checkbox and then Click the Orange Search Button: example below
This search may provide photos associated with your ancestors.
Are you referring to Photographs, on 'On-Line', on the INTERNET?
Or, are you referring to Photographs, in "Memories", in "Family Tree" of 'FamilySearch'?
generally speaking family photos are most likely to be found among extended family - your chances of find them by contacting extended family would be much greater than just doing some general google search.
That being said - The internet and FamilySearch can also be a great tool in helping you connect with that extended family.
give us a little background on your family and situation and maybe we can point you at some possibilities.
have you looked at your family tree in FS
and noted the Memories section to see if anyone has uploaded photos for people on your family tree?