Spiders in their webs often are trickier to shoot than one would imagine. They can move fast, and the web itself dances in and our of the sharpness zone with every little gust of wind. Even though it's perceived dead calm, like with flowers, the wind picks up immediately you haul out the camera
. Must be a special Nature Law for that I suppose.
The web itself and its strand often are better viewed in contrast lighting (light entering from behind), so suggest you try shooting the subject in the opposite direction to get a feel of its appearance under such illumination. Metering is frequently fooled so I often knock down exposure -2 EV or so. You have to try in the field to see how all these elements come together and are rendered in your picture.