MO Tested: Sena Prism Tube Action Camera Review

Evans Brasfield
by Evans Brasfield

Low-priced entry into the action camera market produces surprisingly good video

Sena wants you to have an action cam. How? By creating a low-priced entry into the action camera market in the form of the Sena Prism Tube. For just $119, you get a 1.0-inch diameter by 3.9-inch length aluminum cylinder capable of capturing about two hours of 1080p 30fps video and audio. Once mounted to the rider’s helmet via the included mounting system, operating the unit couldn’t be any easier. Simply sliding the ring around the outside of the tube forward turns the Prism Tube on and begins recording. It’s that simple.

MO Tested: Sena Prism Camera + Video

But we’re getting ahead of ourselves here. Let’s take a look at the unit itself.

The shape of the Prism Tube combines with the helmet mount to make it easy to set the camera angle. The LED on top conveys charging and recording status. (Flashing blue means recording.)

The design is compact and clever. One of the biggest issues with mounting an action cam on a motorcycle helmet is getting the orientation of the camera correct. Sena simplifies this by making the mounting bracket responsible for the up/down orientation while the camera rotates to level the horizon. A red-colored raised portion of the on/off switch indicates which way is up. However, this ease of adjustment is also the Tube’s biggest weakness. It is far too easy to accidentally rotate the Tube in its mount while turning it on or off. The good news is that a well-placed piece of tape easily negates the issue.

Underneath the weather-resistant seal you’ll find the MicroSD card slot, the MicroUSB plug, and the hard reset button (for a frozen camera).

The Prism Tube is sealed from the elements with the exception of the back end of the unit where the MicroSD card is inserted, the format button is located, and MicroUSB plug that charges the battery and allows the external microphone and speaker to plug in. These openings are protected by a rubber gasket and screw-on covers (one for use without the external microphone/speaker and one for use with them), meaning you can use the Prism Tube in all weather. The speaker gives audio feedback for starting and stopping recording and low battery so that the rider can be certain that the unit is operational.

Two other external features of the Tube bear mentioning. The first is the LED on the top rear of the Tube, which indicates recording and charging status. The second is the small hole on the bottom of the on/off switch that uncovers the built-in microphone when the unit is powered on.

The speaker is a nice touch for notifying the rider of camera status. The microphone stays put on a full-face helmet’s chin bar via a hook-and-loop fastener.

If you want to have your video files encoded with the correct date and time as their creation, Sena made this possible for the user by putting a text file on the MicroSD card which the Tube reads and uses to set the clock. Very clever.

Our Prism Tube test unit has been all over the world at various bike introductions and performed flawlessly – with the one exception of its ease of rotation in its mount that we noted above. The video quality of the 125° view compares to its sibling the Sena Prism which similar resolution and costs significantly more. The audio quality is also good, though the microphone can be over modulated if you talk too loudly. With a little practice, you can learn to reduce the distortion.

In the Prism Tube kit, you get the Tube itself, a charging cable, a mount that has two means of attaching to a helmet (a clamp and a stick-on mount point, meaning you could use the two mounts on two helmets), and the microphone/speaker. With a retail price of $119, the Prism Tube is a great way to get into the motorcycle action cam game without breaking the bank.

The stick-on mount maintains a low profile when the camera is not attached.


Evans Brasfield
Evans Brasfield

Like most of the best happenings in his life, Evans stumbled into his motojournalism career. While on his way to a planned life in academia, he applied for a job at a motorcycle magazine, thinking he’d get the opportunity to write some freelance articles. Instead, he was offered a full-time job in which he discovered he could actually get paid to ride other people’s motorcycles – and he’s never looked back. Over the 25 years he’s been in the motorcycle industry, Evans has written two books, 101 Sportbike Performance Projects and How to Modify Your Metric Cruiser, and has ridden just about every production motorcycle manufactured. Evans has a deep love of motorcycles and believes they are a force for good in the world.

More by Evans Brasfield

Join the conversation
  • Nids Nids on Apr 13, 2017

    Used this as a primary helmet cam (side mounted) through a trip in Namibia; quite aerodynamic, which is nice. The battery was never an issue BUT the sliding mechanism used to switch the unit on and off did very poorly due to the sand and dust in the Namib environ. Also, getting the correct horizontal viewing angle was a bit of a gamble. It's a tube, in a bracket with no level guide. Yes, you could use a piece of tape to centre and hold it but then you'd have to remove the entire bracket each time the camera was off the helmet; unfortunately this diminishes the portability aspect. While it's a nice idea and certainly helps to reduce unwanted buffeting it still needs some tweaking and hopefully these issues will be caught and rectified by the design team.

  • Blansky Blansky on Apr 13, 2017

    Used this for a year now and its a low price way to document your trips or people who cut you off. My main issue is the mounting. The clamp will not fit the particular helmet I have and the stick on doesn't last very long. I'm on my third one now.

    As for the nailing the horizontal aspects, I've not had any real issues. You just find your sweet spot with trial and error and check it every time you put on your helmet. If you leave the camera in the holder all the time, the mount stays pretty tight. The holder just slides onto the helmet mount so there is no real need to take the camera out of the holder when you're charging or downloading.

    Some people have complained about recording time as it cuts out after something like 45 minutes, and restarts in another file. So after a 2 hour trip I usually have maybe 3-4 files when I download it. I haven't done much editing but I'd guess that the editing programs would make it pretty easy to cobble the files together.