It seems like many banks are too skittish to loan money for a theater these days. A USDA Rural Development loan may be available, as Keweler said, but I don't think that will be easy to come by either. SBA loans don't seem easy to get nowadays, for sure.
Probably if a bank told you that you need to put 50% down, it is just a conventional loan with them not having any government guarantees. A minimum of 30% down (and often 50%) is pretty much the norm for conventional loans for any business, not just for theaters, as I understand it.
Probably the most likely sources, if the above mentioned sources don't work out, are going to be personal loans. That's right, you need a friend or relative to loan you the money. And for most, that might be difficult or impossible to come by. You may not want to put them at that great a financial risk if it doesn't go well.
If you can't get any kind of loan, the only alternatives left are owner financing of some sort, or bootstrapping it yourself. In case you don't know what bootstrapping is, I will tell you. It means pay for everything yourself. If you have any money in the bank or any major assets to sell, such as a home, land, etc, you may be able to come up with enough money to do something. It just may not be on the grand scale that some hope for.
Some people might have the assets to bootstrap it, but they do not want to take the risk. But that is exactly what you are asking a bank to do. Others would be willing to sell their home or other assets, but the economy is such that selling is difficult. Patience will be necessary.
If my advice seems old hat, then I am sorry. But that is just the way I see it.
I was offering a lease-to-own option on my theater, if somebody would buy the equipment up front, but now others who have a stake in this are not so sure about leasing-to-own or owner-financing because it will put us at much greater risk than selling outright. So that is why owner-financed deals might be hard to find as well. Sellers do not want to wait for 20 years to get their money out of the deal.
Right now, I am just trying to sell for asset value ($275K). Maybe somebody can bootstrap that if they are interested in eastern Oklahoma.