Honestly I'm not sure what difference there is between "photograph" and "photography" (now I looked it up and I would never have guessed) but most languages that have sound changes like that just change the letters between variants of a word, instead of keeping the same letters and changing their pronunciation.

In Dutch, long vowels that turn into short vowels make things like meer/meren (single/plural). In German, you would have Land/Länder (single/plural as well). French also does it with say, régler/règlement (verb/substantive).

English does it too in some cases, with say wife/wives. So it could very well be something like photögraph/phötagröphy. I don't see why it wouldn't work.