To display the seeing limited PSF, you must set the display option on "Seeing limited PSF"

The view port is empty if there is no defocused star analyzed.

This view port shows the PSF (Point Spread Function) of your telescope under seeing limited condition. This view is very helpfull to how the image will be affected by the existing telescope aberrations for a given seeing that match with the seeing of your observation site. Since most telescopes in most locations are seeing limited the alignment of the telescope optics (collimation) is good enough when the seeing limited PSF of the telescope is essentially similar to the DL seeing limited PSF for the same telescope (aka perfectly collimated). This is the point of diminishing return, there is no added value to continue the collimation process beyond this point.

It works like the defocused image view port.

As an example the top view port shows the PSF of a telescope with some aberrations for a very good seeing of 0.5" and on the bottom view port the PSF with no abberations (DL) for the same seeing.

The slider allows to freely switch between the current telescope seeing limited PSF (with its aberrations, if any) and the DL version.

To see the effect of the seeing, you can freely change the local seeing and launch a new analysis.

Bellow the same analysis with the same amount of aberrations but with a seeing of 1.5" instead of 0.5".

The 3D tab allows to watch the PSF in 3D with a better representation of the signal strength and the diffraction rings. To change the perspective in the 3D plot, you press the left mouse button, hold it and move the mouse toward the desired direction. To zoom in/out you must use the mouse wheel.