Hi all
Looking at buying another 'longer' lens for 450D, as are quite a few others by the looks
.... alas budget wont make it for the L series, but seem to be a few around for about $500. Some lens are quoting an inner focusing system, would this suit astrophotography?? (camera on tripod setup) Dont you need to focus?
This is an example
http://cgi.ebay.com.au/Sigma-28-300m...QQcmdZViewItem
Have searched on IIS, and some some good data already, but this focusing thing had me wondering.
Thanks in advance.