Your post has lots of alarm triggers in it!
Why does a business person want you as a partner – you, who by your own account know nothing of the subject area. More, to guess from your post (apologies if this guess is wrong) also have little experience in video production ..?
A cynic might wonder whether your potential partner is looking for someone to cover most of the costs and time in producing an ambitious project s/he can’t otherwise fund – and for which, as is pointed out above, there may be a limited market.
Really, you’re not being offered partnership. Partners don’t do things like “My partner is looking at paying me a low salary & giving me a stake (%) of the company’s profits.”. Partners are in it together.
You are being offered high-risk, low-paid employment with a potential profit share (Shakespeare in Love skewered that one beautifully) by – who? Someone you know well, trust, love? Or a “business person” who chose you – why exactly?
Your posting here suggests you may harbour doubts.
To me, it seems those doubts would be well founded. I’d want to be very clear about what time and money (is he asking you to fund the video kit hire / purchase?) you invest in this project.
In the (unlikely?) event profits do come through, you’d also want to know in advance what rates both your contribution and hers/his would be valued at in calculating your “real” project costs … your partner would want to make up your low wages to fair wages before calculating any profit, right ?
Hope it works out!