This add-on helps you to render different settings easily.

E.g. you want to know, how your render looks like with 30 samples, 80 samples and 200 samples and also with camera depth of field F-stop 0.1 and F-stop 0.5.

All you have to do, is hover over the render samples input field, press S, change it to 80, press S, change it to 200, press S

Same with F-stop, hover with your mouse over the F-stop input field, press S, change the value to 0.5 and press S

Then press Shift-Ctrl-R and all combinations of these values will be rendered:

So you will get 6 Images with values: Samples/F-Stop: 30/0.1, 80/0.1, 200/0.1, 30,0.5, 80,0.5, 200/0.5

All values can optionally be burnt as info into the render: