Realistic exposure time -Alt-az. Syn-scan

[asset189]

As per the title, I have a small skywatcher 130p on an Alt az mount with syn-scan computer controller. My camera is a Sony A5000 ( yes I've since seen the thread ad vision of this camera,s limitations) . If I can mount this camera on this mount what is a realistic exposure time I can expect to capture the milky way ? Currently on a static tripod 13-14 second is all I get before stars begin to blur. Any advice / views

[Steve Ward]

A case of "suck it and see" really ... 

[jimbo747]

At 500ml focal length I can get around a minute directly east or west before errors in tracking and light pollution dominate. Otherwise around 30s. I've been waiting for a clear evening sky the last couple of months to try my 1100d on my SLT mount to find out that very same question.

[Crater]

There are some useful examples of imaging, including exposures, obtained while using Alt-Az mounts, in the excellent forum shown below :

http://stargazerslounge.com/topic/228101-the-no-eq-dso-challenge/page-1

Apart from this, I find that 30 sec exposure times can be used on an Alt-Az mount without excessive trailing/rotation effects.

[wimvb]

My guess is that maximum exposure time depends on where you point  your camera. As long as star trails are straight and parallell lines in your field of view, an Alt-Az mount should be able to cope with them. But near the pole, field rotation should be more obvious. That would also mean it must depend on magnification.