If you have saved your images to your harddisk, open HDR-Shop.
Create--> Assemble HDR from Image Sequence

The following image pops up:


Now load every single image into HDR-Shop. Get sure that you only choose the images you have made from your reflection sphere in step 2. In my case, I made 6 images and usually you get a very good result with six images.

Load Images
.

Camera Response Curve

This setting is very important. Choose the right value, the gamma curve from your camera. For the gamma curve you will find many technical papers, and you can get very easy confused. But the gamm-response curve is very simply. If the gamma value is higher, you will get more contrast into your image. But it depends on the gamma curve from your camera, because every camera has different settings. If you are in luck, you will find the gamma curve from your camera in your manual, than you can choose this value. In my case I have a gama response curve from 1.25. I could also find out, that you will get much better results in rendering, if your HDRI looks like a little bit "washed out", with less contrast. HDR-Images with a high contrast will bring you big parts of noise, and color distortion, because the contrast is to strong.

Calculate Scale Increments

The software calculates automaticly the scale increments. So it´s not necessary to use your own settings. I always choose the automatic calculation for that. Press "Calculate", and than "Generate Image".



Now a new image opens, and you can see your first own generated HDR-Image. Click the middle mouse button, so you can move the image.

With View--> Zoom out / in you can fit the image to your canvas. With + / - you can switch between the different f-stops. Chose the one that will fit best to your real life scene, and click

Image-->Pixels-->Scale to current Exposure

now you have set this f-stop to your favorite one, and this will be used in your 3d software after loading the image.

Select-->Draw Options-->Circle

With that option, we want to select the sphere only. Now click Select-->All.

You can see a line which you can select and fit to your sphere. We want to crop the sphere.

Image-->Crop

Image-->Panorama-->Panoramic Transformations
Will bring you to the following image:



Here you have two sides. On the left you can see the source image. That is our selfmade reflective sphere. Choose on this side "Mirrored Ball". Our destination image should be latitude/longitude, that we will load in our 3d software to use it as skylight.



When this is done, Save as-->My_HDRI.hdr
and choose a HIGH DYNAMIC RANGE RADIANCE FORMAT.

Congratulations, now you have created your first own HDR-Image.
I think now it´s time to play Jail House Rock from Elvis.