The RCC I (Rowe Coma Corrector) is a new type of coma corrector from Dave Rowe with a triplet lens design for F4 Newtonians.
For photographic Newtonian systems where an off-axis guider is used between the corrector and the chip. The RCC I has a perfect chip distance of 91.5mm from the T2 thread. Autoguiding with the RCC, an RCC off-axis guider and the LVI SmartGuider is extremely easy with Newtonian systems.
The RCC functions superbly from F3.5 to F6 - and perfectly at F4. The image scale remains at 1:1 - i.e. the RCC is NOT simply a weak Barlow lens like many other coma correctors, which have a 'Barlow effect' due to the large image distance! The RCC is the only coma corrector which allows the combination of CCD cameras with a filter wheel and adaptive optics systems, without affecting the aperture ratio.
In order to connect the RCC directly to a camera using a T-ring (without an off-axis guider), we recommend the VariLock 46 T2 extender. This already has a point engraved next to the millimetre scale at 36.5mm, allowing the ideal distance between the camera chip + T-ring and the RCC to be quickly set. The three lens-RCC optics system has each glass/air boundary elaborately anti-reflection coated using Phantom Group Coating, for achieving maximum light output.
The knurled stop ring can be unscrewed in order to allow the RCC to be sunk further into the focuser.