What is the purpose of the Orion Optics UK 85mm fixed adaptor ring?
This adaptor sets a precise, fixed spacing of 15mm between two components in an optical train, typically a coma corrector or field flattener and an imaging camera. Using a fixed spacer is essential for achieving the optimal performance from your telescope's optics.
What does "15mm BFD" mean for this adaptor?
BFD stands for Back Focus Distance. This adaptor provides a fixed mechanical spacing of exactly 15mm, contributing to the total back focus requirement of your specific optical system.
Why use this fixed 15mm BFD adaptor instead of an adjustable one?
Fixed adaptors offer superior rigidity and repeatability. They eliminate the possibility of tilt or flexure that can occur with adjustable spacers, ensuring a perfectly solid and orthogonal connection that maintains collimation and optical alignment.
Will this 85mm adaptor fit my telescope's focuser?
The 85mm dimension refers to the specific thread or flange diameter this ring is designed to connect with, which is common on certain large-format Orion Optics UK focusers and correctors. You must verify that the components you intend to connect have a matching 85mm interface before purchasing.
My corrector needs 55mm of back focus. Can I use this Orion Optics UK 15mm adaptor?
Yes, but only as part of a complete spacing solution. This ring provides exactly 15mm of the total 55mm required. You would need to combine it with other spacers (e.g., a 40mm spacer) to achieve the full distance from the corrector's flange to the camera sensor.
Is this Orion Optics UK adaptor threaded?
Yes, as a dedicated adaptor ring, it is designed to thread securely onto other components. However, the specific thread pitch (e.g., M85x1) is not specified, so you should confirm compatibility with the Orion Optics UK components you intend to use it with.
