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Grant,
A Telescope designed and optimised for Astrophotography is called an Astrograph.
Often you can modify a scope to be an Astrograph which involves shortening the length of the optical tube, which gives the ability to bring an imaging chip much closer to the focal plane where the image is flatter.
On a true Astrograph you can do visual but you need to use an extension tube to move the eyepiece back out to the original Focal plane.
Many people have moved their mirror up the tube of their reflectors, or cut off an inch or 3 from their refractors so a camera can reach focus and take advantage of a flat plane zone. Those scopes are now Astrographs.
Other modifications are the use larger secondary mirrors and the use of Feild Flatteners and Focal Reducers (which often determines how much a focal tube must be shortened).
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