Thank you guys
You can see on my images that the Vertex adapter tube has the same diameter that the main NP101is white tube. That allows to install one of the two TeleVue rings and the Losmandy dovetail plate before the rear cell to add extra rigidity and to prevent flexure issues with the load of the FLI ATLAS + CCD camera.
This new mounting should provide a perfect rigidity for high quality images from the huge KAF-16803 chip.
Florent
