Actually, I realized this is only half the answer.
You also need to documents how and when you acquired the items, and the price you paid or their other cost basis.
Then, the deduction you can take for some or all of the items will sometimes be lower than the appraised value. If you are donating items of property that have *increased* in value from what you paid for them, then the deduction value you can claim is
a) the price you paid, if you are donating them for an unrelated purpose, or
b) the fair market value, but only if you are donating them for a "related purpose."
Donating camera equipement to a photography museum, non-profit photography club, or college photography department would be a related purposes and you can claim the full value. Donating them for an unrelated purposes, such as to be sold at auction to raise money when the charity's purpose is not related to photography, means that you can only claim the item's cost.
(In all cases, if the item's fair market value is lower than the price you paid, you can only claim the current value. And it doesn't matter what the charity will do with the items. The rule above only applies for items that have increased in value.)
For items that you did not buy yourself, your "cost" is the price paid by the previous owner if the item was gift, or the fair market value on the date of the previous owner's death, if it was inherited.
