Digital Light & Color

I cannot see alignment points on the overlay image even though I click on the smaller thumbnail. I do see alignment points on the input base image.

They are there -- initially #1 in the lower left, #2 in the lower right, #3 in the upper left, #4 in the upper right corner. They can be hard to see if the background is busy.

I am pretty sure that they are not there on my computer. I can easily see them in the left-hand viewing pane, but not in the right
A second issue. If I'm using Web help, and close PWP 8, the web browser used for help remains open. It seems logical that it close the tab that was started by PWP.

I think that both sets of alignment points, for the base image and the overlay image, should only be visible on the 'Input' preview image (i.e. the left-hand side image, if you display Input and Preview side by side), not the Output Preview image (the right-hand-side). The Output Preview shows the output of the Composite after the overlay image is distorted to make both sets of points align with each other.

You can switch between showing the Base image alignment points and the Overlay alignment points by clicking on the Main thumbnail image or the small Overlay image next to it.

One idea, I'm not sure how good, to avoid the potential confusion, is perhaps to colour the Base and Overlay control points differently so that it's easier to see which set is which?

The alignment points are never displayed on the right hand side, only on the left.

To see them displayed on the base image, click the main thumbnail. To see them displayed on the overlay image, click the overlay mini thumbnail.

There is no way that I know of to close the help tab in a browser from PWP.

OK. Now I see what is going on. (I was using composite on two nearly identical images and couldn't see that image on the left was changing between the imput and the overlay.) Even though I pretty closely read help on the composite transformation, I didn't pick up on the fact that the contents of the left window could either be the input or the overlay. Maybe help could mention this more prominently? Something else that might reduce confusion is to explicitly name which image is in the left window, perhaps in the header, or even a box where I could click on which image I wanted in the window? For me, the current method for choosing which image is not intuitive.

This is one of those things that worked better in PWP 7 where there was a separate overlapping window for each image.

Actually, the caption displayed above the left half of the split screen display already switches to reflect the name of the image when you select the input mini-thumbnail. The box you click to switch images is basically the image browser.

I could possibly add a box something like the image picker in those cases where a transformation has one or more auxiliary inputs to facilitate selecting which input to display. Clicking on the box would display a menu of inputs to select from with the current one highlighted, similar to the current image menus.

Your final idea sounds hopeful. If it is not too much work, perhaps give it a try.
Part of my difficulties were due to the change in operation of the transformation from version 7 to version 8.
A minor change that could have alerted me to the changing contents of the window would have been a momentary clearing the of the window before the replacement image appeared.
On the topic of screen clearing, I find it mildly disconcerting to have the contents of the Image Browser disappear when saving an image.