I highly reccomend this for anyone looking to get passport/visa/ID photos taken.
The staff are friendly and very patient, will take as many photos as you need until you are happy. They use professional equipment, a professional SLR and they really know their stuff.
The best value for money I have ever found and it's in Central London. A much better and cheaper service than Snappy Snaps.
Passport photos, visa photos and ID photos in London for all countries! Very fast process at super prices with the highest customer service. A real photo studio, easy to get to, but a prices you wouldn't expect...