This is my light tent (home made) using this tutorial http://digital-photography-school.com/blog/how-to-make-a-inexpensive-light-tent/ : I take the photo in manual mode, at F4. The background is not perfect white, I use a DAYLIGHT bulb (6400 K). The same problem happen with two bulb. This is the result: I try to shoot in RAW. But I don't know what I need to set to correct the gray background and this settings affect the image ? I think RAW is not the best solution for me. I want to keep the image quality. I use spot metering. Now I don't have more idea, anyone has a sugesstion ? How to correct this problem to achieve a white background ? Thanks!