|
No argument from me there, Dunk. I understand what you and Colin are saying.
The issue comes from what load capacity the mount can take. The size of a 12" Newt means its weight distribution on a mount is not the same as that of a C11 or 12" SCT, even if their dead weights are similar. Add to this the off-set focuser and camera, and the weight geometery/moments, unless this is properly countered, it will add additional inbalance and strain upon the mount. Particularly with a scope this size. The scope does not move in three axis, but four. It is something that is not thought of enough.
Even if the "weight" of a 12" Newt falls within the stated capacity of the mount, this stated capacity does not take into account the moments generated by the size of the 12" Newt. Think of it in terms of levers. Two levers, one longer than the other, and the same load on the end of each lever. The longer lever will be experiencing a greater load. This is also the reason why the focuser/camera combination needs to be countered as well. As the OTA is moved by the mount, the force exerted by the focuser/camera changes, and the flex this will introduce. This is without even addressing the mechanical issues the OTA may have itself.
This has nothing to do with imaging. It's all mechanics, and looking to do what is mechanically best for mount, scope and ultimately the imaging train.
|