There is a serious bug in today's code, 2.4.0 [Build 653896], where whites/clipped pixels are rendered gray. In other words, if the darkest bracketed image has clipping, that area should be rendered white, but its rendered gray. This makes the program unusable.
Reproduced using RawTherapee's TIFFs and Pentax PEFs as input.
Tested the same images in LHDR the last revision to support QT4, 2.4.0-beta [Build cfa8f6], and there the HDR is correct.