how to display an hdr image without tonemapping

I am doing a project 'image based lighting control system'. for that I want to create hdr image from a set of ldr images for finding the luminance of the scene. So I use makehdr command for creating hdr image.Now I want to know how to display the .hdr image without tonemapping, because while tonemapping all the hdr image information will be lost, otherwise I want to if there is any other methods in tonemapping in which all the hdr image information is retained.