Go deeper with focus stacking

By Caroline Schmidt. Posted

While our eyes constantly adjust focus between foreground and background detail, achieving this level of sharpness throughout a scene using a camera is more challenging. Add in larger pixel counts, which means out-of-focus areas look more obvious, wider lenses and a love of large foreground interest, achieving front-to-back focus can be more complex than using a small aperture with hyperfocal distance. On screen this softness is negligible, but the larger you print the more you’ll wish you learnt how to master this powerful pro technique: focus stacking. Focus stacking is when you blend images, shot at varying focal points, and is most commonly applied to macro image to extend the inherently shallow depth-of-field that comes even at small apertures. However, with landscape photographers able to print images larger than ever, focus stacking is becoming a mainstay technique for many professional landscape photographers.

Not every scene calls for focus stacking, however. Often a mid-aperture of f/8 to f/16 and hyperfocal distancing is sufficient for front-to-back sharpness. However, when using an ultra wide-angle lens close to foreground interest or when there’s great distance between the foreground and background, focus stacking is an invaluable skill to have in your back-pocket. It may sound complex but it takes a small amount of extra work during capture and a little time editing, which we share with you here.

As long as the in-camera technique is solid, the latter should be simple. You need to capture a series of images at different focus positions throughout the scene, overlapping the focus areas to extend depth-of-field and ensure edge-to-edge sharpness – perfect for large prints. Here’s exactly how to do it...

1 compose

1 Compose your shot

Find the composition you’d like; do not be afraid to get closer than usual and compose the foreground interest large and prominent in the frame –so long as it falls within the lens’s minimal focusing distance. Outside of this and no matter what technique you use, the foreground will be soft. Use a tripod to ensure all the frames you take are perfectly aligned to make post-production easier.

2 Exposure

Set your camera to manual mode or aperture-priority mode and dial in your lens’s ‘sweet spot’ for sharpness – this is usually between f/11-f/16 – for the Zeiss 18mm it’s f/13. Set a low ISO to maintain great image quality and the necessary shutter speed for an accurate exposure. You may need to add an ND Grad to hold back the sky if it’s too bright in relation to the land – I’ve used a 0.6 soft ND grad.

3 Focusing

Focus on the subject closest to the camera or, in this case, furthest away – you can do this manually or by using single-point autofocus. I use manual focus with my lens focused to infinity and incrementally move the focusing ring back through the frame – it allows me to be very precise. You can use autofocus too by moving the focal point further into the scene with each shot you take.

3 focus

4 Refocus the lens

How many frames you need to take depends on the depth of the scene; it could be as few as three frames or as many as 12, but I usually take more than needed to make sure I have covered every area. Once you take your first image, keeping the camera locked in position on the tripod, carefully move the lens in steps using the focus ring and the distance-scale markers.

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