Hi,
This is going to get slightly technical, but I want to give you a good explanation of what you are observing in the latest screenshots.
To start with, it has go nothing to do with the resolution of the original gobo material we have in the library. The pixelation effect you are seeing is the result of the method used to draw beams when the camera is inside it and aimed into the aperture of the fixture. The method is relatively simple - Capture renders a number of slices of the beam, ranging from the aperture of the fixture to the position of the camera, which is the reason behind the repetitive pattern you are seeing. The more slices Capture draws, the lower the performance, the less we draw the higher the performance but the more repetetive it looks. It is this number of slices that is controlled through the 'Beam atmospheric detail' setting in the rendering settings. From the look of the screenshot I would guess your setting is still on the default 'Medium', although I could be wrong.
On top of this one more thing plays into the result. With lower 'beam atmospheric detail' settings Capture also reduced the resolution of the image projected in the beam, this is to reduce effects caused by taking too few samples in a detailed image. Unfortunately this has the side effect that the resolution of the gobo is indeed lower when looking into the beam. (This resolution reduction has no effect on the actual image projected on scenery though).
Now, the reason this looks so different in Argo from Polar is that in Argo we have corrected the rendering to be more realistic (= physically accurate). Although this has many benefits and makes things look a lot better in most situations, there are some situations like this where things we got away with in Polar now look distinctly 'worse'.
What is important to understand is that this neither a bug nor a lack of gobo data resolution, but rather the technological limitations we currently face witt the graphics engine in Capture Argo. There are a few technique available to remedy this and we have already chosen one of them for our future roadmap, but until we get there I'm afraid all we can offer is the choice of beam atmosphere details available under the rendering settings.