Documentation

Introduction

Multi Remote Camera is a modified version of the full featured, open-source, Open Camera application written by Mark Harman. For information about using the camera app features see http://opencamera.org.uk/

Setup

Enable WiFi control using Settings - WiFi Remote Control turn on enable. The camera app will accept broadcast messages on the WiFi local network to control the camera focus and shutter.

For security reasons some local network WiFi routers block broadcast messages. This prevents Multi Remote Camera from working as intended. For example, my Telecom Internet service provider modem and router blocks broadcast messages in my home local WiFi network. Public WiFi networks outside my home usually block broadcast messages too.

The solution is to set up and use your own private WiFi network router that allows broadcast messaging. A private local WiFi network not connected to the Internet also has an advantage of faster simultaneous camera control because network messages are not delayed by other Internet traffic. All you have to do is change each of your phone's WiFi connection to your alternative network.

I recommend you place your phone in "Airplane Mode" to turn off all radios in the phone, turn off Wi-Fi calling, and then selectively turn on only WiFi and make your connection. Bluetooth can be turned on if needed as another controller. This step is not required but it helps to give you better simultaneous camera triggers by avoiding delays from other message sources.

For my local network I bought a tiny home/mobile WiFi router, TP-Link 150 Mbps Wireless N Nano Router (model No. TL-WR702N). It can be powered with a battery and taken wherever I go to shoot multiple simultaneous photos or videos. I do not connect it to the Internet. I use the default "Access Point Mode" and set up my own SSID network name, "Mobile Photo Net", and password with a laptop computer.

TP-Link also sells a faster router, TP-Link 290A (model No. TL-WR902AC version 3.0). With this router, you can transfer photos using 5G from your phones using the built-in Web HTTP server provided in the Multi Remote Camera app.

Each router has a CAT5 Ethernet port so you could have an Internet connection if you wish. But the strategy for simultaneous capture is to reduce competing internet messages that slow down camera response time. You may also want to shutdown other apps for the same reason. And if you may want to log out of other services too, like email and messaging. However these steps are not necessary, just an option to consider.

Setup Each Camera Device

The Multi Remote Camera app has photo and video filename suffix settings and Time/Number formats for filenames with an option to reset.

In Settings - More camera controls... enter Save photo suffix and Save video suffix.

A suffix string appends to the filename to helps you determine which Android device camera a photo or video was shot. This allows you to merge all photos and videos from multiple cameras into a single folder for editing.

You can also select Time/Number filename formats and Reset photo and video filename number.

WiFi Remote Capture

The free companion app WiFi Remote Capture https://play.google.com/store/apps/details?id=com.andymodla.remotecapture sends broadcast camera control messages for Multi Remote Camera. It uses a simple protocol documented at https://github.com/ajavamind/NX500Capture and describes the command format. Besides phones this app can trigger the Samsung NX500 and NX1 cameras remotely on the local network. The Samsung cameras will need to install a firmware hack.

The WiFi Remote Capture app has focus and shutter buttons and can switch between photo and video modes. Use the focus button to toggle the phone display to show its URL.

The WiFi Remote Capture app also accepts Bluetooth connected device volume up key so you can use an external controller instead of tapping the screen. See Twin NX500 Camera 3D Stereo Rig Using Remote Capture

Using a Linux computer you can also send broadcast messages using the Bash command line to trigger phones on your local network. For example:
echo "V0003" | nc -w1 -u -b 192.168.1.255 8000
will capture a phone video and save to VID_0003_1.mp4

And you can write Python or Processing code to do the same.

To test to see if you can broadcast messages on your local network successfully, press the Remote Capture app, Focus button, several times. You should see the phone's IP address displayed on each screen. This confirms your remote trigger is working. If not, there is something wrong with your WiFi connection or broadcast messages are blocked by the router, or the WiFi Remote Control feature is not enabled.

HTTP Server

The app has a built-in minimal Web HTTP Server to help with listing and transferring photos or videos to another phone or computer on the local network.
Enable the HTTP Server in Settings - HTTP Server turn on. By default the server is disabled.

With the app's built-in Web HTTP server you can transfer your photos or videos with a Web browser. The server provides a directory listing of the folder where Multi Remote Camera stores photos and videos. The server is operational on your local network while the camera app is running and visible or in the background. Use the HTTP server at your own risk.

Alternatively you can transfer your photos or videos to another phone or computer using a separate FTP app or other methods supplied by the phone manufacturer, and other apps in the Google Play Store.

Use the gear Settings - Pairing QR Code option to show the URL of the phone Web server as a QR code or text. To see a directory of the photos or videos, type in the text URL into a Web browser search line from another computer or phone. You should see a listing of each file. Click on the filename to download and display in the Browser download folder. I use Google Chrome. Unfortunately at this time the transfers can only be done one photo or video at a time.

With the QR Code display in Settings - Pairing QR Code you can scan the URL to avoid typing using a free Barcode Scanner app by the ZXing team. The app will automatically show the directory in a browser.

Mouse Control

Enable Mouse Control in Settings, turn on More camera controls... - Mouse button capture to trigger the shutter with a mouse. Connect a wired USB or Bluetooth mouse device to your phone (Some phones need an additional OTG [on-the-go] cable ). Control the camera shutter with a left button click. The right mouse button will display the last photo taken. The mouse wheel controls lens zoom for the camera. The mouse cursor is not active, even when visible, when mouse button capture is enabled. Touch screen is not affected.

You would use a mouse to your phone to take photos with a single phone camera mounted on a tripod when you don't want to use the WiFi remote feature.

I also use this option with two wired mice with button switches wire OR'ed together to trigger two phone simultaneously without using WiFi.

3D Photo Sequential Capture Mode

You can also capture 3D images by taking sequential left and right eye photos, also known as the cha-cha method. Enable Settings - 3D Capture Mode .

A vertical line on the left or right in the display indicates the mode is active and ready to take left or right photos respectively. The mode will automatically add suffixes _l and _r to photo filenames taken sequentially.

To help align the right photo with the left, turn on Camera preview... - Ghost Image - Last photo taken . The right photo to be taken overlaps with the left photo transparently. Move your camera to the right enough to see a small displacement with foreground and midground subjects. Keep the vertical alignment the same as the left photo.

Notes

1. When the phone display is off (although powered up) and Multi Remote Camera is active and has HTTP server enabled, another computer can access the videos and photos in the save directory. You can prevent this by closing the app or disabling the HTTP server
2. When the phone display is off (although powered up) and Multi Remote Camera is active and has WiFi Remote Control enabled, broadcast messages are ignored so that no focus or shutter command requests operate.