You are correct that you can file a DBA to use for your photography purposes. All accounting and tax would roll up to the corportation. However, if I understand the process correctly, you can't just incorporate your existing business. What you have to do is establish the new corporation and then transfer the assets of the existing business to the new company. This would mean you would need a new tax ID. Additionally, there are tax implications with the transfer of assets.
Here's a link to an article that explains the process pretty well but doesn't go into the tax stuff. You'd probably be better off to talk to a CPA about that.
How to Incorporate a Sole Proprietorship | The Startup Lawyer