In the old days, it seems it was quite easy to get candid photos of geisha. Several foreign photographers travelled to Japan in the late nineteenth century and took many revealing photos of geisha indicating that they were able to actually spend a great deal of intimate time with them. Examples of such photos include:
Geisha in various states of undress
Geisha dressed in western clothing and in western themes
Geisha with their hair down in natural poses
All manner of studio poses
These photo series were distributed as photo cards and were popular in the west. These days this kind of exploitative photography of geisha has ended. The world of Geisha has increasingly been restricted to the Japanese elite with few opportunities for foreigners to participate. Geisha clubs are normally by invitation only and you need connections for an invitation. If you are invited nobody is going to be happy with you taking lots of photos.
Not to worry, you can photograph Geisha on the streets of Kyoto. But there is a hitch, it is popular for Japanese tourists to dress as Geisha when visiting Kyoto. These tourists rent real kimono and have professionals do their make up. It is difficult for foreigners to tell the difference between the real geisha and the tourists.
Japanese tourists dressed as geisha
If you go to the Gion district of Kyoto in the early evening you can see real Geisha walking to work. Japanese are often too polite to chase these women down for photos but I have seen foreign tourists literally chasing these women down the street.
Maiko on her way to work
Geisha on her way to work
Another way to get a photo of a Geisha is to wait for them after their work and follow them home. However, taking flash photos of a lone woman walking home at night is not exactly good form in Japan or anywhere else.