IP life would be a lot simpler for me if a copy of the Undo/Redo buttons was placed on each of the processing dialog boxes. That would simplify and speed up experimentation.
I can't tell from your description which preview mode you are using but if you are using the Undo/Redo buttons that much you are probably in accumulate mode (gray frame around the image). Accumulate mode is the default image update mode when IP is installed. In this mode filters applied to an image accumulate and you must use the Undo button after each operator if you are trying to fine tune the filter.
Preview mode (blue frame around the image) works in the opposite way. In this mode you can apply a filter to an image continuously until the correct setting is found. After the filter parameters are adjusted you must save the current displayed image in memory by pressing the reset preview mode toolbar button. Now you can repeat the process with another filter. Most operators have sliders and checking the Enable Slider box cause the operation to be done whenever the slider is moved otherwise you will need to press the Apply button.
Most operators but not all operators are preview mode enabled. The help file show which operators are preveiw mode enabled. Any operation the changes the actual pixel width or height of an image is not preview mode enabled. Iterative restoration or any other multi- threaded operator (yellow frame around the image) are not preview mode enabled. Operators that are not preview mode require the use of the Undo button between applications if you not not want the operation to accumulate.
Compare mode (green frame) and New mode (red frame) are two other image update modes. I almost always use preview mode (blue frame) and rarely use the other image update modes except for the multi- thread mode (yellow frame).
