Acher - Not an easy subject.
I was puzzled at first but I'm guessing from the lack of shadow that the web was some distance from the white wall. I noticed you used spot metering and this has resulted in near perfect exposure on the spider and prey, however the web has disappeared which does give it that floating look that Mike mentioned. I can't easily see how you could get round this problem (not a big one) short of a more elaborate lighting set-up or dispensing with flash altogether.
Your focussing is excellent - did you use manual or autofocus? IMO your choice of f/16 was a good one and your image has good detail and dof which supports this choice.
Personally I like to see the spider's eyes in a photograph - but with insects and spiders you "takes wot you get" and they rarely make it easy for you.
I agree that available light can produce a more natural and more pleasing result than flash. However in my experience conditions in the field are rarely right for non-flash insect/spider photography so I just work on improving my flash technique and try the occasional natural light shot when I think ambient conditions favour success.
Overall I think you've done a really good job with these photos. My only slight criticism would be the subject viewpoint. Having said that, I would think that your first, nicely detailed pic makes a useful ventral id shot.
Bruce
