it's more like a tip than a whole tutorial

. ..remember to install pfstools (or qtpfsgui if you don't like to work in console)
http://pfstools.sourceforge.net/http://qtpfsgui.sourceforge.net/1.- First we need to render an Angular map, changing the camera type to ... guess what... Angular

. "Angle" and "Max Angle" set to 180 and don't forget to check "
Mirrored" and "
Circular" buttons.
2.- The render must be a square image so change the resolution in Blender. In the example is 1400x1400.
3.-Render and save in any format you want but EXR and HDR will let you use the image later as IBL. (Make your own Light Probe images is really easy

. )
4.- in console you just need to go to the folder where the angular image is saved and run the command
"
pfsin [angularmap name] | pfspanoramic angular+polar -i -o 5 -y 0 | pfsout [spherical map name]"
in the example I run
pfsin angularmap.exr | pfspanoramic angular+polar -i -o 5 -y 0 | pfsout spherical.jpg
* if you want to resize the image just change "-y 0" for "-y W" where W is the final image width in pixels (in the example -y 700 will produce the same spherical map but at half size)
* "-o 5" is for oversample factor. normal values are 3 to 5
5.- The Spherical map can be open with any Panoramic viewer.. I tried PTviewer and FSPviewer.
Now... for all you guys that really hate to work in console, Luminance 2 (known as Qtpfsgui) will make your life easier, but you will need to work with HDR images (exr or hdr). Just open the angular.exr and then go to
Edit -> Projective Transformation. and set:
Source Projection: Angular, Destination Projection: Polar, Oversample 5 and click OK
after that you can make tonemapping and save as PNG or JPG.