How Coverage knows.

The active area of every recording mode.

A camera doesn't have one sensor size. It has one per recording mode, and the mode decides what a lens has to cover. Coverage stores 749 modes across 71 cameras (66 digital, 5 film): the active width and height in millimetres, the diagonal, the resolution and the format class. Film gates follow the published SMPTE and ANSI aperture standards.

Each camera links to its maker's page, so you can check the figure yourself.

What the lens sees on that sensor.

Field of view comes from the focal length and the active area of the exact mode. The model is a rectilinear lens focused at infinity: it doesn't include focus breathing or distortion.

For anamorphic lenses, the viewfinder uses the desqueezed field: the sensor width multiplied by the squeeze, so a 2× lens on a 3:2 mode frames like the scope picture you'll deliver. Zooms use the focal you pick, stepped along the usual cine marks and both ends of the range.

The maker's figure, checked.

Every lens carries the image circle its maker publishes. For the 704 lenses in the major cine sets, that figure is pinned to the maker's own datasheet, and anything more than 0.05 mm off is corrected on the next catalog update. On an 8K VistaVision sensor with a 46.31 mm diagonal, a 0.3 mm error is enough to flip a lens from "covers" to "vignettes", which is why the tolerance is that tight.

Lenses don't end in a hard line.

A published image circle is one number, but light fades towards the edge, and how far you can push a lens depends on how much fade you'll accept. For 282 lenses in 33 sets, Coverage uses measured illumination for each focal instead of the single figure:

D is the diameter where the light falls to 25% of the centre. H is where it falls to 10%: the point where the light runs out.

The measurements come from ARRI's Lens Illumination Guide, from Hawk, Vantage and Tribe7's published coverage tables, and from our own flat-field measurements, calibrated against ARRI's guide to within about half a millimetre on average. Zooms are measured at several focals and interpolated between them.

Covers, tight, or vignettes.

The circle sits centred on the sensor, so the question is whether it reaches the corners, half the diagonal away. With a measurement, the verdict uses D and H; without one, it uses the published circle with a half-millimetre safety margin.

A model built for cine glass.

The darkening you see in the projection and the viewfinder comes from one falloff model. It follows the lens's coverage circle, its focal length and the T-stop you set: wide lenses lose more at the edge, and stopping down flattens the curve.

The textbook cos⁴ law treats the focal length as the distance to the exit pupil. On a cine 8mm that predicts about 4.5 stops of loss at the edge, while an Ultra Prime 8 measures about 1.3, so Coverage uses a curve tuned to real cine primes instead. It's a model, not a measured curve for each lens.

Your phone, zoomed to the cine lens.

The iPhone's cameras run as one virtual camera. Coverage works out the frame the cine lens sees on your sensor, then sets the phone's zoom so its live 16:9 picture just covers that frame. iOS hands over between the ultra-wide, wide and tele cameras as the zoom changes.

When the cine lens sees wider than the phone's widest camera, the live picture sits inside the frame and the border shows the extra field the phone can't capture. Past the phone's longest lens, the picture is enlarged digitally. If your phone's field of view differs from the stock figure, calibrate it in Settings.

Near, far, hyperfocal.

The viewfinder's focus readout uses the standard thin-lens depth-of-field formulas, with a circle of confusion chosen by format: from 0.015 mm for Super 16 up to 0.045 mm for 65 mm. T-stops step in thirds.

MTF50, where it's known.

Where it's known, a lens shows its MTF50 at the centre and in the corner: the finest detail, in line pairs per millimetre, that still holds half its contrast. That's 39 lenses so far. We're adding makers' published MTF charts set by set.

Read from the houses' own lists.

Each of the 474 rental houses in 73 countries is linked to the lens sets it lists on its own website. Most lists were last checked on 30 September 2026. Houses can send corrections at any time, and they go into the next update.

Every change goes through the same tests.

The catalog is validated on every change: no duplicate lenses, every rental link has to point at a real lens set, and retired names are rejected. Audits flag any image circle outside the usual range for its format, and any lens that sits far from the rest of its set, so a typo can't hide.