TDS,
I spent most of last Summer flying P1 from the right hand seat on aerial photo 'sorties'.
It's simple -
Is it legal? Yes, doesn't matter where the commander sits so long as he/she is a pilot and has access to the full range of controls.
Is it safe? So long as you have recent currency and are comfortable flying from the RHS, then yes. I won't patronize you with the ins and outs of why, as I'm sure you're aware, suffice to say, remember you'll be throttling with a hand not used to throttling, and controlling with a hand... Etc.
Be safe, and if in any doubt, go up for a few circuits with an instructor first
p.s. despite the remark above, the pictures will never be as good through perspex, curve or no curve. You'll only get the best quality when there's nothing between the camera lens and the object(s) you're shooting. Have you considered the Cessna 172 - you can open the whole window then!