The view through the eyepiece tube of the reflector telescope can be confusing, hence this page.
A sheet of yellow paper has been placed behind the secondary mirror to help identify its edge.
The view through the focus tube of a typical 200mm (8″) f/6 Newtonian Reflector
Showing n reflections in the sight/focus tube > secondary mirror1 > primary mirror2 > secondary mirror reflection3
Using a Collimation Cap
Using a Combination Cheshire / Sight tube Collimation tool
Reflections viewed through the sight tube of a Newtonian Reflector
Showing n reflections in the sight tube > secondary mirror1 > primary mirror2 > secondary mirror reflection3
Acknowledgement: I am indebted to Vic Menard for his invaluable assistance in checking the accuracy of these images.
Finally, some representations of the view down the eyepiece that I can actually match to what I see! Very helpful thanks 🙂
You are welcome Andy