Bellows Factor

A handy application for large format photography enthusiasts.

rdq - smart productivity tools · com.rdq.photocalc

Not rated yet 1K+ downloads v2.50 2.6 MB Android 5.0+ PEGI 3 · Everyone

Download APK 2.6 MB All versions

Signature matches the Google Play version Details

At a glance

Latest version: v2.50 (250)
Updated: May 8, 2026 (5 months ago)
APK size: 2.6 MB
Requires: Android 5.0+ (API 21)
CPU support: Any (no native code)
Category: Photography (app)
Listed since: Aug 18, 2021 (at least)
Website: rdq.cz
Developer contact: [email protected]

About this APK

Bellows Factor is an app by rdq - smart productivity tools in the Photography category, listed since at least August 2021. It has no native code, so it runs on any Android processor.

What's new in v2.50

- Storage access permission removed - Fixes & improvements

Description

From the listing uploaded by “appupdater”.

Bellows Factor can help you to achieve better if not perfect exposures with large format cameras. The basic operation includes calculating the bellows factor in EV based on your focal length and lens extension. These values can be inserted in either millimeters, centimeters or inches depending on the lens or the photographers' preference. But that’s not all. Bellows factor can be combined with any number of filter factors so a correct exposure factor is computed based on the lens extension and filters used. The Bellows Factor application comes with the predefined set of well known photographic filters and their EV factors that you can modify and customize based on your own collection of filters because we know, that every photographer has their own selection and favorite combinations of filters.

Security & authenticity

Security rating: Trusted

Signing certificate

Signature matches the Google Play version Checked by the source store on May 8, 2026.
Certificate issued to “rdq” This is the certificate of the Google Play version.

Store checks and file details

Developer signature verified May 8, 2026
Validated against Google Play May 8, 2026
Signed byO=rdq
Signing certificate (SHA-1)7C:AF:1A:DE:63:D9:3E:33:CD:0C:AB:45:86:7C:C6:F3:1F:62:F0:B0
File MD5ab747b621d6d89bffdef3721d99411c8
Uploaded by “appupdater” Gold tier · 117,810 followers · uploading since 2020

Scans and ratings come from the source store; the certificate comparisons are AAPKs's own, made from the files' published signatures. AAPKs doesn't scan files itself — compare the MD5 and signer after downloading.

Required hardware & features

Basic touch input android.hardware.faketouch

Bellows Factor APK: questions and answers

Can I install this APK over the version I already have?

Yes, if your installed copy is older. It is signed like the Google Play version, so Android installs it as an update and keeps your data.

Is the Bellows Factor APK safe?

No one can promise that a file is safe, but some things can be checked. The source store rates this file Trusted. Its signature matches the Google Play version. After downloading, check that the file's MD5 is ab747b621d6d89bffdef3721d99411c8.