On the internet, I stumbled about some questions about what HDR files are.
An HDR image is an HDR file encoded and saved by HDR software to retain the high dynamic range nature of the originally generated data.
Please take a look at my two example hdr files here:
Easy HDR Files | Swiss Alps | HDR with Dramatic-Dark settings
Easy HDR Files | Swiss Alps | HDR with high contrast properties set
Those two example hdr files above have been created with easyHDR software. But at the end, they are still “normal” image files as JPG or PNG.
Saving source HDR files
Within easyHDR, it’s possible to save concrete HDR files directly to disk. This way, you’re able to reopen the HDR files again. So this is a real source HDR file, saved by easyHDR as openEXR, an high dynamic range imaging image file format (fortunatelly released as an open standard along with a set of software tools).
easyHDR Files saving as OpenEXR
Now let’s compare those hdr files, especially the file size is very interesting. The rendered HDR files are exactly the same size as the original three JPG photos.
But the saved openEXR HDR file is much bigger. This is because easyHDRÂ has saved all the HDR rendering information within this file format. So I can reopen this exr whenever I want and so some HDR rendering modifications, for example reder it by one click from “dramatic dark” to “night”.
HDR files saved as exr (huge filesize)
To complte this post, I’d like to provide the three source files (in JPG format, of course):
Easy HDR Files | Swiss Alps | Non-HDR-File (original) Light Exposure +0.7 (overexposed)
Easy HDR Files | Swiss Alps | Non-HDR-File (original) Light Exposure 0, good quality image
Easy HDR Files | Swiss Alps | Non-HDR-File (original) Light Exposure -0.7 (underexposed)