1 Take a test shot
To see if the lighting and background are right for your chosen cobweb, fire off a test shot. Spiderwebs look best contrasted against a dark, clutter-free background to avoid their fine strands getting lost. If there’s no dew in the morning, consider applying a fine mist of water but be gentle. If the web is directly lit by the sun, you may find that you need to reapply the mist as it evaporates.
2 Exposure
It’s your choice whether to use aperture-priority or manual mode, but you’ll need to dial in a mid-aperture (f/8-f/11) and keep an eye on your shutter speed to ensure it doesn’t drop below 1/160sec if you’re handholding. If you’re using a tripod, you’ll still need to be watchful of the shutter speed to freeze any movement of the web caused by even the slightest breeze. Adjust your ISO rating to suit.
3. Composition
As you’ll be working within a few centimetres of the web with a 1:1 reproduction ratio (or similar), you’ll need a mid-aperture of at least f/8 to get the spherical beads of water sharp – even if the web is parallel to the imaging sensor. As you change the angle of the sensor to the subject, or get closer, you’ll find depth-of-field falls off dramatically and you’ll need to stop down the aperture further.
4. Refine your focus
Even with apertures of f/11-f/16, depth-of-field can still be shallow so your focusing has to be precise. Set your camera to shoot in burst mode to increase your chances of a sharp shot and use manual focus or single-point AF to accurately align your point of focus. Aim to focus in the middle ground so you have out-of-focus foreground to lead the viewer into the web and background bokeh.
5. Your background
Look for a dark, clean background that’s at least a metre away, with no distracting variations in colour or highlights to make best use of the shallow depth-of-field. Ideally you’ll find a backdrop in shade, that’s not affected by the backlighting illuminating your web, but if you find your background is too bright and the web is lost try adding up to a stop of negative exposure compensation.