Kader Director’s Viewfinder – A Modern Android Viewfinder App Built by a Working DP

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by Johnnie BehiriAugust 27^th, 2026

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Director’s viewfinder apps have quietly turned into an Apple story, with the most notable recent releases in this category landing on iPhone, iPad, and Mac. Kader is an attempt to fix that from the other side of the ecosystem: a director’s viewfinder written natively for modern Android phones by a cinematographer based in Graz, Austria. Let’s take a closer look at what it does, and at the limits worth knowing before you rely on it during a scout.

Kader is developed by Harry Kemp and distributed through Google Play. The app uses your phone’s camera to simulate the field of view of a chosen cinema sensor and focal length combination, switching automatically between the ultra-wide, wide, and telephoto modules to pick the one that requires the least cropping. It ships with aspect ratio presets running from 9:16 to 2.40:1, a default lens list that can be extended with up to 20 custom focal lengths, and a zoom mode covering 4mm to 999mm. Anamorphic work is handled by focal length multipliers for 1.33x, 1.5x, and 2.0x, and the sensor library spans formats from Super 8 up to 75mm. We have not run Kader through our own scouting workflow, so what follows is based on the developer’s documentation and the public store listing.

Why Android shooters have been the poor relations here

The last twelve months have been unusually busy for previsualization tools, and almost all of that activity has happened on Apple hardware. The Vienna-based Cadrage team launched Cadrage Studio in early access and then moved it to a full release on macOS and iOS with subscription pricing. Chemical Wedding and Cadrage both added sun tracking to their viewfinders within days of each other, and LIGHTFRAMER PRO arrived as an iPhone-only viewfinder combining framing with sun position and LiDAR focus tools.

Android has not been abandoned entirely; Magic Cinema ViewFinder has been available for free on both platforms for years, and older cross-platform options still sit on Google Play. The problem, as the developer frames it, is maintenance rather than availability: opening a viewfinder app that has not been updated in years and watching it stall or crash while a client looks over your shoulder. There is a technical reason for that gap, and Kader’s documentation is refreshingly blunt about it. iOS covers a handful of camera hardware configurations; Android covers thousands, each reporting its lens and sensor characteristics slightly differently, and a viewfinder app is only as accurate as the metadata the phone hands it.

How Kader handles accuracy

Rather than shipping a hard-coded table of phone models, Kader reads the camera metadata your device provides and crops the live image to simulate the selected focal length. The developer states the field of view maths is exact, but that the underlying device data is not always trustworthy, so absolute accuracy across every Android handset cannot be guaranteed.

The mitigation is a focal length offset, adjustable in 1mm increments, that lets you calibrate the app against a known reference on your own phone; once dialed in, that offset carries across sensor and lens combinations. Anyone planning to hand scout images to a DP or a client should calibrate once against a real camera and lens before trusting the framing. The 999mm ceiling on zoom mode is another consequence of the platform, imposed in full-frame equivalent terms by the current Android camera ecosystem according to the developer.

Metadata burn-in and on-set organization

The metadata strip is the part of Kader that looks most useful in day-to-day prep. Every capture carries its project name, sensor, focal length, aspect ratio, and timestamp visibly in the frame, so a scouting folder still makes sense weeks later when nobody remembers which images were shot at 35mm on Super 35 and which were 50mm on full frame. A recent update added device orientation and tilt angle to the burnt-in data, which helps when reproducing a low or high angle on the shoot day.

Captures are grouped into projects and scenes, with in-app albums and automatic folder creation in the device gallery, and sharing runs through Android’s standard share sheet. There is no cloud sync, no account, and no collaborative layer, which puts Kader firmly in the single-tool camp rather than competing with the connected pre-production suites we have covered recently.

The limitations to know before you install

The Google Play listing carries an unusually honest note stating that the app is still in development and that some users may encounter bugs. Devices running NothingOS currently cannot use multiple camera modules at all, a platform limitation the developer attributes to Nothing’s own software, with no timeline offered for a fix. There is also no Kelvin white balance control, because the native Android camera APIs do not expose true Kelvin values and faking the numbers would mislead more than the missing feature does.

Custom sensor sizes are not supported. The built-in library is described as continuously growing, with a recent update adding the Sony FX6, Sony BURANO, RED V-RAPTOR 8K VV, and several FUJIFILM X-series bodies. The developer also notes that Sony does not publish sensor dimensions or exact crop values for recording modes other than native sensor resolution, which limits how precisely any viewfinder app can simulate a Sony camera’s cropped modes. Anamorphic support remains a focal length multiplier rather than a full desqueeze workflow, and one user review on Google Play describes that support as limited.

Privacy is a genuine differentiator

Kader works entirely offline, with no account, no ads, and no internet connection required for its core function. According to the published privacy policy, no user data reaches the developer’s servers, and all image processing happens on the device. More interesting for anyone scouting sensitive or NDA-bound locations, the app actively strips GPS coordinates, device make and model, serial number, and camera owner information from the EXIF data of saved images, writing only the application name and capture time. Location scout images travel far and wide through production chat groups, and stripping coordinates by default is sensible design rather than a marketing bullet.

The next big feature update is coming in early September. It’s currently being tested and will include Video Mode, PDF Shotlist Exports, Dual Aspect Ratio options, Focal Reducer options, and a whole bunch of additional sensors & recording modes (Sony FX5, BM PYXIS 12K, Canon C50, C70, C80, Ronin 4D 8K, Panasonic S5, Sony ZV-E1 & more).

Kader is available now on Google Play, where, at the time of writing, it shows a 4.9 rating from 13 reviews and more than 100 downloads, making it a young project rather than an established standard. The developer states the app carries no subscription and no advertising, and full access is offered free for life to students and staff at educational institutions, a program he says more than 250 people have joined. (To get a free install code, please get in touch via the website from a .edu email address or with proof of enrollment/employment). For us, normal users, the app will cost around 11.42 USD/9.80 Euros. More information is available on the Kader website, and the app itself can be found on Google Play.

Has the lack of maintained viewfinder apps ever pushed you to an iPhone for scouting, or does your Android workflow hold up? Don’t hesitate to let us know in the comments below!