The RunCam Split 2 by RunCam is the second iteration on the only viable solution that marries an FPV camera with an HD action camera using a single lens. This is an attractive offering for those looking to consolidate their builds. It’s also ideal for getting HD recording capability on smaller frames. I thought it would be a perfect solution for my 4-inch build based on the Shendrones Tweaker frame.
The RunCam Split 2 sells for $79.99 USD and you can get it from RunCam’s Store, GetFPV, Amazon, or a number of other sources. It comes with the camera/board, mounting hardware for the board and camera, an extra (longer) cable to connect the camera to the board, several wiring harnesses, and a pluggable WiFi module for use with a smartphone. You’ll need to supply your own SD card (Class 10 or higher, up to 64GB).
What’s New in Version 2 of the RunCam Split?
The RunCam Split 2 seems more like an update to the V1 hardware than a true version 2. There are very few functional changes or new features. The changes directly address some of the most common complaints about V1.
RC25G ‘GoPro’ Lens
This lens became so popular on the Split 1 that RunCam began offering it as an upgrade at purchase, and it’s now the default lens on the Split 2. My understanding is the RC25G has a slightly more narrow field of view than the original version 1 lens, which helps reduce visibility of the propellers in HD recordings. It also produces higher quality video.
VBAT Voltage Input
Version 1 of the Split took a 5V voltage source, which is common for FPV cameras. This is a problem because the module consumes up to 650mA. Most 5V regulators found on PDBs or flight controllers can only supply 1A of current. This doesn’t leave much room to run other peripherals off the 5V regulator. The Split V2 has an input voltage of 5V-17V so you can power it directly off your battery (2S-4S) with no current draw concerns.
WiFi Module Included
The WiFi Module was optional on version 1, but it’s included with version 2. I feel that the mobile app (which uses the WiFi connection) is extremely useful for configuring the Split, so I’m glad to see the module is included by default.
There are a number of physical changes in version 2.
- Connection points have solder pads instead of connectors.
- An additional metal layer that goes over the board to help hold the SD card in place and protect the electronics. The tab holding the SD card in place can lift out of the way to remove the SD card without taking the whole electronics stack apart.
- The SD card holder has been replaced with a regular spring loaded SD card slot.
- WiFi module inserts horizontally instead of vertically.
- Improved microphone
Assembling the RunCam Split 2 is straightforward. It comes with a simple user manual with pinout diagrams and physical assembly instructions. It comes with two types of camera mounts to support a variety of frames. I had to get a little bit creative with my frame because the front standoffs are ever-so-slightly in the way of the camera mounting bracket. I ended up mounting the bracket upside down through holes in the top plate. This location moved the assembly back about half a centimeter, which is plenty of room for the mount.
The kit comes with eight silicone O-rings which should be mounted above and below the board. The rings protect the SD card in crashes. The buttons, LEDs, and USB/WiFi ports are all on the sides of the main circuit board for easy access. My only complaint is that the circuit board overhangs the standard 30.5mm footprint by a couple millimeters on each side. It’s not drastic, but it might be a problem for smaller builds. If you’re trying to build a very small quad, I recommend looking up the dimensions on the product page on RunCam’s site for both the board and the camera mounting options.
Keep in mind that this adds an additional board to your electronics stack. If you’re using a frame without much vertical room, make sure you do some measurements before buying. This should be easy to work around as all-in-one FC+PDB+ESC boards are becoming more and more common.
Finally, you’ll probably want to soft mount the camera to reduce jello in your HD recordings. ‘Jello’ refers to wobbliness in video footage due to vibrations. I expect some silicone O-rings or a layer of TPU between the frame and mounting bracket would be enough.
The RunCam Split 2 is fairly simple to operate. There are three modes: video mode, photo mode, and OSD setup mode. “OSD setup mode” refers to using an OSD menu on your FPV to configure the camera settings. The camera does not feature an integrated OSD like on the Swift 2, unfortunately.
A group of four LEDs indicate module power, WiFi power, mode, and recording status. Two push buttons are used to power on/off, change modes, start/stop recording, and navigate the settings menu. Some learning/memorization is required, because the buttons can be short or long pressed for a variety of functions.
The camera overlays a red, blinking dot in the top right corner of the video feed while recording is enabled. If you like a feature packed OSD, you might have to adjust the layout to avoid this dot. I don’t think it will be a problem for most people, and it’s a nice feature. The dot is only present in the FPV feed, not the HD recording.
Recorded video and photos can be obtained off the SD card through the micro USB port on the side of the board so you don’t need to remove the SD card.
The UART connection from the flight controller allows you to control the RunCam Split 2 with transmitter channels. You can map up to three channels to control Wi-Fi power, recording status, and camera mode.
This feature has great potential, but the current implementation is pretty cumbersome (at least in Betaflight. I have not tested KISS). Switches/Channels map to modes in Cleanflight/Betaflight, similar to arming or airmode. However, switching a RunCam Split mode on is equivalent to pushing a button on the board. Switching the mode off is the same as releasing the button. I expected to be able to map a switch to on/off to start/stop recording. Instead, one must toggle the switch off and on to start, and again to stop recording. This true of the other two channels (mode switching and WiFi power).
This is a limitation of the RunCam Split Communication Protocol: there are only three messages which simulate button presses. In order to properly implement switch positions, the flight controller must query for the current state of recording, WiFi power, or mode of operation. It’d be great to see the RunCam firmware expand this communication protocol to include more getting/setting operations. If all camera settings were exposed through this protocol, OpenTx could see new features that allow pilots to configure the RunCam Split directly from their transmitter (just like video transmitters).
For now, it’s still nice to be able to get to and navigate the settings menu from the transmitter. I’d recommend mapping these channels to momentary switches on your transmitter if possible. I have the start/stop recording channel mapped to my Taranis X9D’s momentary switch.
WiFi Module & Mobile App
The WiFi module and mobile application are extremely useful. You get access to all of the settings directly on your phone (Android or iOS only) and avoid needing to navigate the menu through your goggles. This makes up for my complaints about the transmitter control functionality. In addition to settings, you can also see a live preview of the HD feed. Experimenting with exposure, white balance, and field of view is easier with the preview. You can also view recordings and photos directly on your phone.
Propellers in HD Footage
The most commonly cited drawback of the RunCam Split was the fact that propellers (and sometimes the edges of the frame itself) are visible in the HD footage. This is true of the Split 2, though I’m told the RC25G lens reduces the problem slightly.
Having the propellers in the HD field of view is unavoidable with this style of camera, and I don’t consider it a flaw of the product. It comes down to personal preference: Some people like having the propellers in the field of view for a cockpit-style effect, and others don’t. Either way, this is an important point to consider when deciding between the Split and a more traditional FPV cam plus separate action camera setup.
I think having the edges of the frame standoffs in the footage is more bothersome, but this is just a matter of physical placement of the camera mounts. You should be able to get creative with any frame and mount the camera far enough forward to avoid getting the standoffs in the corners of the footage.
The settings menu does let you adjust the field of view of the HD recording. Narrowing this a little bit might help get the propellers out of the frame.
The RunCam Split (both versions) has increased latency compared to other FPV cameras. This is a valid concern: Latency is one of the most important factors that affects FPV flight. A pilot’s ability to react depends on latency: The faster a camera frame hits the eyeballs, the faster a flight adjustment can be made.
Oscar Liang has a great method for testing camera latency, and has already collected data on just about all the major FPV cameras, including the Split (his numbers are for version 1, but since version 2 appears to be mostly a physical update, I expect the latency to be about the same). On average, the Split has around 50ms of latency, which is about 25ms more latency than other top FPV cameras.
Here’s the thing: More latency is bad, but the FPV camera is not the only component of total latency. There’s also RC latency (time between moving the stick on your transmitter and it reaching the receiver), flight controller latency (time between an RC command reaching the flight controller and it having an effect on the output signals to the ESCs), ESC latency (time it takes the ESC to physically adjust the speed of the motors to match the RC command).
All of these latencies are orders of magnitude smaller than the dominating factor: Human reaction time. Reaction time is something around 200-250 miliseconds for the average person. In other words, it’s going to take 200-250 milliseconds from when the images hit your eyeballs until your brain is able to make decisions based on what it sees. From there, latency increases based on good a pilot you are, and how quick your decision making or muscle memory is.
I suspect that the extra 25ms of latency isn’t going to truly matter unless you’re an expert pilot. Furthermore, I think it will matter most to freestyle pilots because they’re more likely to have to react to unknown obstacles. Racers are generally aware of specifically where they’re going, and the brain can actually compensate for latency by making stick movements slightly in advance of the video feed.
I have no complaints with video quality. The FPV footage is clear with reasonable exposure response. The HD recordings are comparable or better than other HD cameras of this price point. It records 1080P at 60fps (using a class 10 or better SD card — slower cards do work but are throttled to 30fps) and wide dynamic range.
Unfortunately I don’t have any flight footage uploaded at this time. If you want to get a look at some HD footage, check out some of these reviews on YouTube. My experience matches what you see in this videos.
- Albert Kim’s Review (HD flight footage starts at about 4:45)
- AndyRC’s Review (DVR and HD flight footage starts at about 17:30)
RunCam Split 2 Conclusion and Recommendation
I think the RunCam Split 2 is a complete no-brainer for beginner and intermediate pilots (which is most of us). Lesser experienced pilots crash more often, and the RunCam Split is well protected inside the aircraft’s frame. You don’t have to worry about matching the angle of two separate cameras. This makes experimenting with different FPV camera angles much easier. It’s also quite a bit cheaper than purchasing an FPV camera and HD action camera separately (unless you have several aircraft — then sharing a single HD camera might be cheaper). Finally, I argue the extra latency matters less to newer pilots.
The RunCam Split 2 is also an obvious choice for smaller builds where weight is a premium.
It’s a tougher sell for expert pilots, for a few reasons. First, top freestyle pilots are usually monetizing their FPV footage in some way. Having propellers in the corners of the frame might be a deal breaker. Also, expert pilots have great muscle memory and are more directly limited by system latency. For this reason, the extra latency will have more of an impact.
At any rate, I’m thrilled with the RunCam Split 2. It’s going to have a permanent home in my 4-inch Tweaker build.