Just an update on how I'm getting on with autoguiding (keep the forum going!). Put it to the test again last night from the back garden before I start heading to darker sites. Much better then previous efforts, graph showed pretty smooth spikes in both RA and Dec this time around. Did some tweaking with values which obviously helped. Got good polar alignment using the RA scale on the mount which I avoided at first cos it sounded complicated, but is actually very simple and accurate. Here is a 5 min exposure on Betelgeuse at 100% crop, slightly oval stars but not noticable unless cropped at 100% which I wouldn't be doing anyway due to noise:

This is just one frame, no dark subtraction etc. Not bad. Then tried a ten min exposure on Procyon (100 ISO) and was very pleased with this one. Again it is 100% crop with only slightly oval stars:

So looking good, just waiting on the moon to go away and clear skies! A rarity these days, especially since I started this hobby.