Licensing work taken on another client's project - specifically an aerial helicopter photo flight

I do a lot of aerial photo work over Chicago for commercial real estate developers, architects, and the like. Chartering a helicopter is not a cheap thing - nor easy to coordinate - but when my clients need aerial work done, they'll pony up for it. Sometimes when I'm in the air and done shooting my client's work, I'll peel off the target property and take some 'personal' photos. FWIW, I always charge my clients for the time I spent on their project only. I.E. if my flight was 45 minutes, but I was on their project for 35, they're charged for the 35 minutes.Anyway, I come away from these flights with a lot of valuable images (even when I'm "on target" it's easy to point my camera in another direction and quickly 'snipe' a few cool photos. Sometimes it's like shooting fish in a barrel). Inevitably, I share some of my personal work to my social channels and existing clients (or perspective clients) reach out about said images. Inevitably, I show them some photos - and usually have even more RAW images that suit their needs.After that long story, here's my question. While I'm confident my ability to price an image (I've been in business for 10+ years), I'm never completely sure how to factor in the added cost of creating those licensable images. For the client commissioning the photos/flight, it's easy to tack on an expense line item. But for the other clients who want existing photos from those flights, things get a bit blurry. On one hand, I can say "well, you lucked out I took some shots on that flight." and charge them what I normally would for their required usage. On the other hard, it hardly feels fair to the commissioning client that a third party shouldn't pay a premium for those photos since my original client (or I) had to incur an additional cost to get those photos.Sometimes I want to say "had you commissioned me to fly this project for the photo(s) you're interested in, the charter cost would have been $XXX extra, and I have to add that to the licensing fee." But this doesn't feel totally fair either. Had they commissioned me, I likely would have taken more photos for them and/or better ones since that would have been my main target/focus.So, how do you handle licensing photos for which there was an extra, large expense to initially create, but was already reimbursed by the commissioning party? via /r/photography https://ift.tt/3iI8qvX