Thanks for pointing this out. It was some retarded error on my side when defining the ray's bounding rectangle.
Should be corrected and up on mega.nz
As for the rays and all other markings remaining when grabbing an image of the blank clock, that is intended so that the user has the possibility of capturing these as well.
The intended way to have a clock w/o rays & other markings is to remove them before grabbing the image.
Regarding different or all kinds of rays shown on the clock, that's a different animal.
For now the entire "clockwork" inside the program is designed to have one of them exclusively. That's why the toggle button jumps when selecting another type of rays.
Changing this might require a bit more work – will think about it and see if I find time to do that.
The "primitive" workaround would be to have several instances of qcv running ….