I have a Sony VX2100, not exactly designed for Extra lens attachment i know, but i wondered if theres any sensible option for extending the Zoom without using the digital zoom, which quite frankly is pointless

Its never bothered me only having the short zoom, but this weekend there was an oportunity of a good shot but it was a bit too far away

So, my question is.......

Would something like the numerous Tele Zoom lens' on ebay be any good ( opting for a good brand of course ) - the ones that just screw onto the filter thread, or do these distort the picture either when zoomed in all the way or fully zoomed out

Or is there any other options out there that are sensible ?

By sensible i mean not expensive, as if i was going to spend loads i would just look for a camera with longer optical zoom

So would a Tele zoom be ok, or are they best avoided ?