If you made all thinks right and your render still isn't the same . This can be that i put here an image of a converted openEXR file.
If you look at the last pictures name it is " sun_from_EXR_output.jpg ".
By rendering and saving a standard BMP file you can not have the same appearance.
You have to save the render as an EXR file. If you don't have a software that can open or edit EXR files take a look at this :
http://www.xnview.com/en/downloadwin32.htmlDownload the bottom " XnView v1.97
Complete version (Some Plugins/Addons & NConvert, ShellEx, Media Detector) " file.
I made the conversion with this. I like Xnview and use it all the time.
But ı don't remember about the EXR plugin for Xnview if it is right away there or if you have to search for it.
If you install xnview be careful and install it in custom mode. I dont install in default mode any software.
You have this way better control of the adjustment . And some applications tent to put garbage on your system sometimes.
You may know this things but maybe it is helpful for others
Cheers.
Kadri.