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| Twin Smartphone 3D Camera, Bluetooth Remote Controller, and OWL viewer |
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| Twin Smartphone 3D Camera Lens in OWL viewer |
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| Twin Smartphone 3D Camera in OWL viewer |
During the summer 2019, I went to my first National Stereoscopic Association convention, 3D-Con, in Akron, Ohio, USA. It was a great experience. I learned a lot about 3D stereo photography, saw wonderful 3D Art, photos, and videos. I met expert 3D enthusiasts who graciously shared their knowledge and Art.
3D Camera Phone Rig
Before attending the convention I was experimenting with making a 3D camera rig using twin smartphones mounted with magnets. During the convention my ideas for this 3D camera project came together and I was able to complete a working system upon my return home.
Convention vendors sold all kinds of 3D related gear and Art. At the London Stereoscopic Company booth they sold the "OWL - Stereoscopic Viewer" for viewing stereo cards. I bought my OWL viewer on-line a couple of years ago, but I found out they now offer a Virtual Reality kit that uses a magnetic board for securing a phone to the viewer. I bought the magnet board holding plate from LSC to hold my twin phones in the OWL.
My 3D camera rig consists of two identical Samsung Galaxy S6 smartphones mounted in portrait mode, side by side, in the OWL viewer and held in place by the magnet. I placed a adhesive metal sheet bracket on each phone case to cling to the magnet. One of the S6 phones was used before I upgraded and the other I bought used on EBay. I cut two openings in my OWL viewer for charging cables and a hole for a 1/4 inch tripod mount.
In the OWL the phone camera lenses appear above the OWL frame unobstructed. Looking through the OWL lenses you can see in stereo the camera screen images. This turns out to be a good way to preview the depth of the scene you want to capture. The preview helps you determine if you are too close or too far from your subject besides helping with composition framing. The OWL rig mounted smart phone camera lens separation (inter-axial) is 75 mm in portrait mode. By coincidence the FujiFilm FinePix Real 3D W3 camera has the same lens separation distance. See the rig photos above.
Camera App
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| Open Camera Remote App Icon |
I could have used the Samsung camera app that came with the phone, but I wanted a wireless trigger for both focus and shutter controls.
At the convention there was a discussion group about using smartphones to capture 3D. The Hyper3DPhone app was identified as a possible app for twin Android smartphone cameras. It works by pairing two phones over a Bluetooth connection and triggering one phone sends a message to the other to also take a picture. Although it worked well for triggering two phones nearly simultaneously, its weakness was that I had to touch the camera screen to take a photo and there was a lack of camera control features I use in other camera apps.
For several years I have been extending features of the open source Android Open Camera app to include wireless remote control. My modified app is named Open Camera Remote and you can install it from the Google Play Store . My app uses WiFi broadcast messages to trigger focus and shutter remotely on multiple phones connected to a local area network. Newer versions of the camera app permit control using wired and wireless Bluetooth keyboards, mice, and other game controllers. In addition I added a tiny HTTP Web Server in the app retrieve photos and videos taken by the camera and stored on the phone. This was my choice for a camera app in my 3D OWL rig.
Wireless Focus/Shutter Trigger
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| 3D Camera in Owl Viewer with Bluetooth controller work in progress. |
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| Bluetooth Camera Remote Shutter |
I used two Bluetooth camera shutter remotes as pictured above for my DIY controller. I needed two, one for each smartphone, because two phones cannot share the same Bluetooth remote connection. I took the circuit boards out of the remote and wired them to switches and battery power in a case shown below.
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| Home-made Bluetooth Remote for Twin Cameras |
The remote control circuit boards were wired to trigger simultaneously with the push of a single button switch. Two diode OR circuits permit a single switch for focus and another OR circuit for shutter release to bypass the built-in controller switches. The controller's large button does focus (volume up, Android key code 24) and the smaller button does shutter release (enter, Android key code 66). The camera app settings have to be set to use the volume up switch for focus.
Synchronization of the cameras is just OK with variable results. Good synchronization of the two cameras depends mostly on how long it takes for the cameras to focus before taking a picture. To make sure focus does not interfere with synchronization, first I touch the screen to select my subject that the camera will focus on. When both cameras are in focus, then I press the shutter button to take a picture. I use the focus switch to focus repeatedly on the subject to make sure focus is achieved before pressing the shutter control switch.
I got better synchronization when I placed the camera apps in manual focus mode. But I found it too cumbersome to make sure the focus distance was the same for each camera.
Here is a video demonstrating the 3D Camera in operation.
Viewing 3D Using the OWL
After taking a picture you can view it in 3D with the OWL by tapping the right bottom corner preview icon on each phone to launch your photo viewer of choice. I use the app I wrote 3D/VR Stereo Photo Viewer in 2D mode for viewing my photos. Other photo viewing apps work just as well. The Back button on the phone returns to the camera app. |
| 3D Smartphone Camera Tripod Mount in OWL 3D Viewer |
Since writing this blog last October, it's now mid May, 2020, I have used the rig with twin Samsung Galaxy S8 phones that have a much better camera with improved results. I also experimented with the 3D Stereo Photo Viewer app running on a Rokit 3D Pro phone to retrieve photos from the twin phones for display on its glasses free 3D display screen. That's another future blog posting.
