Light & Deep app icon

Light & Deep

a rangefinder, a light meter & a director’s viewfinder — in one iPhone app

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Free, in beta on TestFlight iOS 17.6+

Light & Deep app icon

See before you shoot.

Light & Deep is an iPhone app. It's a rangefinder, a light meter and a director's viewfinder in one. Plan your shots, develop an intuition for exposure settings, see the expected depth of field.

It's in beta on TestFlight. Everything unlocked, so you can test it out. Try it and tell me how you like it.

2.4 m 6x7 · 80mm · f/2.8

Runs on any iPhone. Depth measurement needs an iPhone Pro.

Why did I make the app?

Recently I've build a custom camera - simply by combining a Schneider Angulon 53mm f4, a Mamiya Press back, and a customized 3d printed cone. It's fun to use, but framing and focusing with this thing was not easy. And slowing down to measure exposure was also annoying - the camera was meant to be more of a medium format point-and-shoot. So I developed the app, specifically to solve these pain points, but then...


..but then I found myself using the app more and more just on the go - to plan a shoot, or to see what lens I would need to bring, and if the light in the evening scene is strong enough for an ISO 100 film. The app also shows very clearly the depth of field at specific aperture settings and film formats - a very helpful tool that supports my eternal fight against the urge to shoot wide open all the time..

Try the app, it's free now, and even on release it will retain a limited but useful feature set in the free version. But let's get back to the marketing copy, it's hard enough to explain all the features in text..

Three tools, one app.

Rangefinder. Light meter. Viewfinder.

Depth visualisation

Two ways of measuring distance:
Set a distance, and everything at that distance lights up. Pre-set your camera to the same distance, and you know immediately what is in focus.
OR
Place a point by tapping the screen, and you'll always see the distance towards that point.

Light meter

Point the camera at the scene. Set the ISO, and the app gives you the correct exposure settings. Aperture priority or shutter priority - you choose which one stays fixed.
Place a point on the screen, and the light meter turns into a spot meter - automatically adjusts the settings to correctly expose the chosen area.

Film format viewfinder

Pick a format and a focal length, and the frame lines change according to your choices. You see what fits, what doesn't, and how you want to compose your frame. Forty-nine formats available, from Super 8 to 20x24 inch.

A live preview of your depth of field!

Actual depth of field preview!
Based on aperture, film format, focal length and distance, the app calculates what will be in focus, and highlights it with a zebra pattern.

Forty-nine formats.

Select any format as your viewfinder preset, from half-frame to large format panoramic.

35mm

Full Frame, Half Frame, Cine, Panoramic, Sprocket

Medium Format

645, 6x6, 6x7, 6x8, 6x9, 6x12, 6x17, 6x24

Large Format

4x5, 5x7, 8x10, 11x14, 16x20, 20x24

Panoramic

XPan, 6x12, 6x17, 6x24, large-format panoramics

Digital

Full Frame, APS-C, APS-H, Micro Four Thirds, Digital Medium Format

Professional Cinema

Super 8, Super 16, Super 35, ALEXA 35, ARRI Large Format, VistaVision, 65mm, IMAX 15/70

Helpful little features.

0.5x ultrawide

Switch to the ultrawide iPhone lens for the wide focal lengths that won't fit the normal field of view. LiDAR still works in the middle of the frame. Honestly that feature was a bitch to build.

Parallax correction

Mount the iPhone on your camera and set the lens offset. Frame lines shift to compensate for the parallax between the two lenses, so that you see the same framing the camera sees, even at close range.

Black & white preview

See the scene in monochrome to preview your black & white shot. It's a decent approximation of how a panchromatic film will render the same scene.

Reference shots with metadata

When you save a frame, exposure, distance, format, and focal length get written in a strip along the bottom - so when you're in the darkroom a week later, you still remember your settings.

Light meter calibration

The default light meter calibration works well. Still, you can adjust the calibration offset for your iPhone to match your professional light meter.

Customize for your shooting style

Zebra colors. Crosshair styles. Frame styles. Grid overlays. Opacity. All of it adjustable.

Distance point tracking

Tap a subject, and the measurement point stays on it while your camera moves around. It does not track moving objects, but points in space.

Made for you.

Large and medium format photographers

Use the app to quickly see how you want to position your heavy camera, how you want to frame your shot, which lenses to choose and whether that ISO 100 film is actually enough.

Cinema and pre-production

It's a director's viewfinder, but with DoF visualization and a light meter built in! Very helpful when scouting locations, composing shots, and getting the right lens selection before the shoot.

People learning the craft

Change the aperture. Change the format. Change the focal length. Watch the in-focus zone grow and shrink in real time. It's the fastest way to build intuition for camera settings.

3D-printed camera builders and users

As fun as 3D-printed film cameras are, they often lack a good way to reliably frame the shot and get the focus right. Light & Deep solves it, as it replaces the light meter, range finder and viewfinder in one app.

FAQs

How do I become a tester?

Tap the TestFlight link above on your iPhone or iPad. Install TestFlight if you don't have it. Accept the invite. That's it. While the app is in beta, every feature is unlocked and there's no payment involved.

How far does the LiDAR reach?

About five meters - that's the limitation of the sensor. And that's the range where a rangefinder matters most: portraits, still life, macro, close-quarters documentary.

Does the depth display work in ultrawide (0.5x)?

Partially: LiDAR coverage is limited to the center of the ultrawide frame, and a small parallax offset is visible at close distances. Honestly a miracle I got it to work at all. And it's still useful for previewing the wide formats, and no other app I know of offers LiDAR rangefinding at 0.5x.

What devices does it run on?

Any iPhone or iPad on iOS 17.6 or newer. The light meter, viewfinder, and framing tools run on all of them. The LiDAR features - depth overlay, spot distance meter, depth-of-field preview - need an iPhone Pro (12 Pro or later) or an iPad Pro (2020 or later) - those models have a LiDAR scanner.

How accurate is the light meter?

Like other light meter apps, it calculates ISO, shutter speed, and aperture based on the camera sensor readout. Think of it as a reflective meter, comparable to metering on a modern digital camera. If pre-set calibration doesn't match your external light meter, you can adjust the calibration offset in the setting for each iphone lens.

Is it useful for cinema or video work?

Yes. There are 11 cinema formats, from Super 8 to IMAX 15/70, and the depth-of-field calculation uses each format's own circle of confusion. I talked to a few DoPs already and am very open to suggestions on how to improve the app for that use case. Reach out to me if you have any feedback!

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