canon /opticron setup (1 Viewer)

Hi i have been experimenting with my canon 10d and opticron hr80 scope ,as i wasnt to happy about the camera weight being mounted on the filter thread i constructed a bracket out of aluminium, i am still trying small mods so will post info later. basically i am using a canon 50mm f1.8 lens set on manual focus infinity,the camera is set on app priority f1.8 100 iso it is set up to look through the HDF zoom eye piece which on this scope gives 24-72x zoom focus using the scope,there is absolutely no vignetting at any zoom setting but i seem to be suffering from low shutter speeds which i assume is not enough light getting to camera, lowering the exposure setting improved thing alittle.
i m quite hopeful i can iron out the wrinkles and i think the results will be quite acceptable,has any lens expert out there any better choice of lens which will increase light input plus would a fixed eye piece let in more light i have included my best shot yet, any help will be appreciated thanks paul

I think that the light input is constrained by the 80mm objective lens on your Opticron scope, not the Canon lens, so there is nothing you can do apart from use a higher speed film emulsion (say 400ASA) or flash.

I presume the shot of the heron was either saved at low resolution or is an enlargement taken from a much larger photograph?