The following diagram is based on a 12.5 inch Primary mirror and a 2.5 inch secondary in a 15 inch telescope tube. As you can see less than half of the Curved Vane is in the light path and is not much longer than that in a straight vane spider. We have heard remarks made by our competitors that our Curved Vane Spiders have too much Vane in the light path, and that their 60 degree vane designs are better. The fact of the matter is that our Curved Vane Spiders are closer to 60 degrees in the light path than theirs, and we do not have the stability issues that are encountered with hard angles at the mounting point with the telescope tube (this almost always leads to vibration).