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No guiding = no round stars except at 15 second exposures. Even a high end mount requires guiding.
Yes good polar alignment is needed but you still need guiding.
The target is to get round stars at 10minute exposures for cooled astro ccd cameras.
To achieve that you usually need an off axis guider and a guide camera.
An off axis guider attaches in front of the camera and filter wheel and has a pick off prism that shoots some of the light looking through the telescope up to a small guide camera.
Guide cameras are usually something like:
Starlight Express Lodestar X2 (the most sensitive)
SBIG Sti (has a built in shutter which I like)
QHY 5
There are others but those 3 are probably the most popular and they are small like an eyepiece.
Some use a guide scope mounted on top of the main scope with a guide camera in it. That works but is more likely to cause problems as the guide camera is no longer looking through the imaging telescope so if there are differences in flexing between the scopes you will get elongated stars from that factor - usually its slow to build up to elongation but will damage 10 minute subexposures.
Some SBIG cameras have a guide camera chip installed inside them or fitted to the filter wheel. This is popular.
QSI, Moravian offer models with filter wheel and off axis guider built in which makes it all a lot easier. QSI being the leader there. QSI 2nd hand prices are falling as a result of newer sensors coming out that offer an upgrade to existing QSI owners so you may be able to pick up a nice QSI 683 WSG 8 for less than you would've a year ago.
That would be my pick. A QSI 683wsg 8 or the 5 model (5 positions in the filter wheel or 8). 1.25 inch filters which are the cheapest.
Greg.
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