To load an image into HDR Shop, you can either choose Open... from the File menu, or simply drag the image file onto HDR Shop. You can also open multiple files at the same time this way, by choosing them in the Open File dialog or dropping them on HDR Shop.
If the image loaded is a high-dynamic range format, it loads up instantly. However, if you are loading a low-dynamic range format, HDR Shop pops up the "Specify Camera Response Curve" dialog:
The reason for this is that HDR Shop stores image pixels internally as numbers relative to the amount of light they represent. Unfortunately, the 8-bit pixel values in most traditional images don't have this property. For example, in a jpeg, a pixel of 200 is not twice as bright as a pixel at 100. In fact, in most formats, it is over four times as bright. The standard mapping (on PC's at least) is called a gamma 2.2 mapping. This means you take the pixel value and raise it to the 2.2 power to get a number proportional to the amount of light. So, for most images, you can just use the default gamma 2.2 curve. If you want to be more precise, you can derive the exact curve for your camera by going through the Camera Response Curve Calibration tutorial. You can load the resulting camera curve through the 'Custom Curve' tab on the dialog:
Now that you have an image loaded, the general interface controls can be found under the 'Help->Quick Help' menu entry or by typing 'Ctrl+H' or by clicking here.
Let's perform a simple operation on the pixel values so that they are all scaled by 1/2. Under the 'Image' menu, choose 'Pixels->Scale...'. Enter '0.5' in the Red, Green and Blue boxes and hit 'OK'. The image pixel values are scaled by 1/2.
Now let's save the image in a particular format. From the 'File' menu, choose 'Save As...'.
A window appears and you choose which image format to save the image as. Choose a format,
location and filename and hit 'Save'