RASA 11 Lens Group Reflection Blocker

thingiverse

For RASA 11 scopes with UFC or other wide bore camera attachments (to avoid vignetting, correct for tilt, use filters, etc...), there are internal reflections caused by the lens group as detailed in this thread on cloudynights: https://www.cloudynights.com/topic/804923-rasa-11-problems-with-reflectionsrainbows-caused-by-bright-stars/ This part will fit between the lens group assembly and the camera attachment to block the reflections from the lens group. The ring should be pushed back with the prongs facing you, until the tip of the prongs rest between the threads and the front mounting plate (See photo). This keeps the ring locked into place close to the lens group, and should not obstruct the F2.2 light path for APS-C sensors and smaller. I printed in black and sprayed with black spray paint (Rust-oleum "high heat for grills" - this paint will not reflect in UV/IR) as seen in the attached photos. Note: This is a delicate part and meant to be so, as the prongs need to flex without warping the ring too much. As long as it is held in pace securely where it belongs, I think it should be just fine. Time will tell. Update: Found additional rainbow reflections so expanded the ring by 2mm. Updated .stl file. 9/27/2022