Ok, let me just preface this by saying that I am not a CPA, but I am a senior Accounting college student taking a tax course, and work for a CPA in a large business.
The first thing the IRS is going to look at if you deduct your purchases is whether or not your photography business (I'm assuming that's what this is) is a legitimate business or if it's a hobby. There are 9 factors which the IRS uses to determine whether it's a hobby or a business. Without going through all of those, it basically needs to pass the "smell test". It needs to SMELL like a legitimate business. Just a few things include whether or not you made a profit, your history of profits in prior years, etc.
You can deduct them either way. Ideally you want it to be trade or business, because then you can deduct your expenses on your Schedule C. If it's a hobby, you can deduct it on your Schedule A, under Miscellaneous deductions. The problem with this is that it's subject to two cutbacks. First, you can only deduct your expenses up to your gains. So if you only made $200, you can only deduct $200 worth of expenses. Secondly, your miscellaneous expenses are subject to a 2% Adjusted Gross Income "haircut". Basically, that means that you take your AGI and multiply by 2%. If your expenses do not exceed that number, you can't deduct anything.
Hope that helps a little!
Tyler