Lenses, depth of field and bokeh

The 3D Editor's camera behaves like a real camera with a real lens. The fastest way to a look is to pick a lens: one click sets the focal length, opens the aperture to the lens's widest, and gives the out-of-focus highlights (the bokeh), the vignetting and the film that lens is known for. Everything after that is fine-tuning. Both renderers draw the same lens: the realtime view to work in, the path tracer for the final image.

This page belongs to the 3D Editor.

Pick a lens

Open the Camera tab of the inspector. The first row of its Lens section, Lens, opens the lens library: every lens with its photograph, its name and how it is sold (for example "85 mm f/1.4"), grouped by what it is for. Hover a card for the look and the shots it suits. Click one to mount it. The mounted lens shows under the row with its spec and its look.

The lens name at the right of the camera bar at the top of the viewport does the same from a menu.

Mounting a lens:

  • sets its focal length and widest aperture, and turns Depth of field on;
  • replaces the whole look of the previous lens: its bokeh, vignetting, distortion, focal plane and film;
  • leaves the focus where it is, and leaves a prism filter on (a filter sits in front of the lens).

Change any of the lens's own settings afterwards and its name reads "(edited)". Changing the aperture or the focus does not edit a lens: a lens stopped down is still that lens.

The lenses

These are modelled on real lenses: the look each is known for, not a measurement of one copy.

Reference

  • Ideal lens: perfect optics. Round, even bokeh at any aperture, no vignetting. A neutral start, or for technical renders.

Portrait

  • Sony FE 85mm F1.4 GM (85 mm f/1.4): smooth, round, modern portrait bokeh. Head-and-shoulders portraits, product hero shots.
  • Nikon AF-S 105mm f/1.4E ED (105 mm f/1.4): the subject lifts off a background melted into colour. Half-body portraits, fashion.
  • Sony FE 100mm F2.8 STF GM (100 mm f/2.8): an apodization filter feathers every highlight's edge, velvet-soft. Portraits and still lifes against busy lights.

Standard

  • Canon RF 50mm F1.2L USM (50 mm f/1.2): bright and creamy with a soft glow wide open. Everyday scenes, interiors, people in their place.
  • Leica Noctilux-M 50mm f/0.95 (50 mm f/0.95): dreamlike glow, strong cat's eyes, razor-thin focus. Night scenes, lights in the background.
  • Zeiss Otus 55mm f/1.4 (55 mm f/1.4): clinically corrected, neutral discs and no colour fringes. Products and architecture where the blur must stay clean.

Wide & tele

  • Sony FE 24mm F1.4 GM (24 mm f/1.4): a wide view that still separates a near subject. Environmental portraits, rooms.
  • Canon EF 200mm f/2L IS USM (200 mm f/2): compressed perspective, the background a wash of colour. Distant subjects, cars.
  • Canon EF 100mm f/2.8L Macro IS USM (100 mm f/2.8): close focus with clean round bokeh. Jewellery, watches, food.

Vintage

  • Helios 44-2 58mm f/2: the Soviet classic, a swirling background and glowing highlights. Portraits in foliage, fairy lights.
  • Meyer-Optik Trioplan 100mm f/2.8: soap-bubble bokeh with bright, crisp rims. Water or leaves sparkling against the sun.
  • Lomography Petzval 85mm f/2.2: a strong swirl around a sharp centre. Painterly portraits.

Early photography (these come with black-and-white film)

  • Daguerreotype Achromat 64mm f/2.9 (the 1839 design): the first photographic lens, a soft glow on orthochromatic film. Portraits as if from the 1840s.
  • Dallmeyer Petzval Portrait (1860s): Victorian studio portrait, sharp centre and swirling dark edges, orthochromatic.
  • Kodak Brownie meniscus (1900, fixed f/11): the box-camera snapshot. Soft corners, bent lines, nearly everything in focus, orthochromatic.
  • Leica Elmar 50mm f/3.5 (1925): the first 35 mm street lens, on panchromatic black and white. Street scenes, 1930s reportage.
  • Zeiss Sonnar 50mm f/1.5 (1932): film-noir glow wide open, panchromatic. Night scenes, smoky interiors, classic Hollywood portraits.

Cinema

  • Cooke S4/i 50mm T2: the "Cooke look", a warm gentle fall-off and soft-edged bokeh. Film frames, flattering faces.
  • Cooke Anamorphic/i 50mm T2.3: tall oval bokeh, cinematic depth. The image itself is not squeezed; the ovals are.

Special

  • Samyang 300mm f/6.3 Reflex: a mirror lens. Ring-shaped highlights and a fixed aperture.
  • Canon TS-E 50mm f/2.8L Macro: a tilted focal plane, the toy-model look. Cities and landscapes from above.
  • Sigma 8mm F3.5 Circular Fisheye: a round 180° image in a black frame.
  • Samyang 12mm F2.8 Fisheye: a frame-filling fisheye, bent lines and huge depth.

Which lens for which look

  • A product or portrait that pops off the background: a long, fast lens close to the subject. The 85 mm or the 105 mm at its widest. The longer the lens and the nearer the subject, the softer the background.
  • Creamy, calm background: the STF (feathered edges) or the Otus (clean discs). Avoid the Trioplan, whose rims make a busy background busier.
  • Sparkle and character: Trioplan for bubbles, Helios or Petzval for swirl, Noctilux for glow. They need small bright lights behind the subject.
  • Film look: a Cooke; anamorphic for widescreen night streets.
  • Old photograph: an Early photography lens. Daguerreotype or Dallmeyer for the 1800s, Brownie for a 1900s snapshot, Elmar or Sonnar for 1930s black and white.
  • Everything sharp: stop down (f/8 or more), or switch Depth of field off.

How the settings work together

  • Focal length sets the view and, with the aperture and the focus distance, how much is blurred. Blur grows with focal length squared at the same aperture: a 100 mm at f/2.8 blurs a far background far more than a 24 mm at f/1.4.
  • Aperture (the f-stop): smaller numbers open the lens, for shallower focus and bigger bokeh. A lens opens no wider than its own widest stop; the choices under the slider start there.
  • Stopping down changes a lens's character, as it does on a real one: wide open the opening is round, with the lens's cat's eyes, swirl and glow at full strength. One stop down the iris closes into its blades (seven blades make heptagons); two stops down the cat's eyes, the swirl and most of the vignetting are gone; the glow fades fastest. An Ideal lens looks the same at every aperture.
  • Focus: set it by distance, by picking a point, or with autofocus. The bokeh's size depends on how far things are from the focus distance.
  • Vignette darkens the corners, as old and fast lenses do wide open.
  • Film: Colour, B&W (panchromatic film: every colour as grey, roughly as the eye sees brightness) or Ortho (orthochromatic film, early photography: blind to red, so reds and skin go dark and blue skies go white).

Fine-tuning the bokeh

The Bokeh section shapes the highlights: the shape (Iris, Ring, Heart, Star), blade count, curvature and rotation, plus a gallery of bokeh-only presets. Character holds the rest:

  • Anamorphic: oval bokeh.
  • Rim: positive gives soap-bubble rims, negative feathered edges.
  • Cat's eye: bokeh toward the frame edges clipped into cat's eyes.
  • Swirl and Swirl onset: the Petzval swirl around the centre.
  • Aberration: spherical aberration. Positive softens and glows the background bokeh and gives the foreground ones bright rims; negative is the reverse.
  • Colour fringe: axial chromatic aberration. Bokeh edges turn magenta in front of the focus and green behind it.
  • Onion rings: concentric rings inside each bokeh, the trace of aspherical lens elements.

Realtime and path traced

Both renderers draw the same lens. The path tracer is exact. The realtime view approximates the blur closely, but cannot blur in a light that sits just outside the frame. With Colour fringe on, the path-traced image needs more samples to lose its colour noise.