Thankyou all for your comments! Not using a tripod, focussing was extremely difficult and I had to resort to moving the entire camera closer and farther from the spider until it looked like I had the focus. Shot about ten frames, all are as blurry as this one. I wasn't going to enlarge any of them, but as they were on the same roll as something else I was enlarging tonight, I thought I'd try one. It seems it turned out to be a 'happy accident'!
Ps, Aggie, the spider was only a common garden Wolf spider and wasn't very large, only about an inch and a half across it's legs.