Many people remove the clamp and place the lamp directly on the screen. This is not a very good method as it will make you remove the lamp to get into the tank which will allow the tank to cool down and shorten the life of the bulbs by banging them around. Also this does not allow you to adjust the distance of the lamp to give you the proper flood of heat and the desired hot spot. Now you could get a dimmer but I'm not really a fan of them.

I prefer to use a lamp stand. This allows for a che or lamp to be pointed as desired and leaves the heat source in place when entering the tank so the tank does not drop in temperature.
The big box pet stores should have these for around 20 bucks. I don't know why amazon has them so high unless they have gone up in price. Its been sometime since ï have bought one.

http://www.amazon.com/Zoo-Med-Reptil...ile+lamp+stand