framebuffer clamping

I’d like to accumulate some data (RGBA) in the framebuffer but I don’t want them being clamped…
Does someone knows if there is an other way to do that without setting a floating point render target?

The framebuffer is always clamped.If you need to do some advanced accumulation, such as rendering in stages, I would recommend the accumulation buffer.

Originally posted by jtipton:
The framebuffer is always clamped.
Thats not ture. With ARB_color_buffer_float extension you can control color clamping using floating point buffers.