A quick tip for those of us who may not have access to precision engineering skills. I wanted to use my trusty old Pentax Takumar bayonet-mount 50 & 135mm lenses with my QHY8, having previously bought the nose piece mounting adaptor clamp from Peter Tan.
To cut a long story short, Peter offered to have the correct adaptor made up, in aluminium, with male T thread on one end, Pentax female bayonet (camera-side) receptacle on the other end, spaced to allow correct focus distance for a QHY8 sensor to lens. All for AUD45 plus postage. Bought a few other trinkets to defray that. Peter gives good service!
Total length is about 20cm and I just checked it, works great. Now for those nice ultra widefield shots with my QHY8 on a guided mount!