Paralenz+ Review

Date: 2020-03-05 · Word Count: 2478 · Reading Time: 12 minutes

Recently, Paralenz announced their next generation of dive cameras, the Vaquita which prompted me to write up this post about the things I love and the areas I’m hoping they will improve in the next generation. My summary on this device is that the hardware is very good and the software is mediocre, it’s worth getting as long as the caveats don’t impact your use case (although at this specific time, I’d wait for the Vaquita which should come out in April).

Let’s start with what I love about the Paralenz+ (affiliate link). The physical build quality of the camera is excellent. No housing or other extras to go wrong and it goes down to 200 meters. It’s well designed to be able to use easily underwater (and with gloves) with simple controls which move easily and are intuitive. It comes with a mask strap attachment which works well for me (although you certainly want a second attachment point, I attach to my BCD shoulder ring, and it can be fiddly until you get used to it). While some people find their regulators vent in just the wrong place or they’re not able to adjust it to be tight enough to not wobble, these have not been issues for me and my only nice to have would be a better cutout for ears as it sometimes shifts and digs a little during a dive. I also love the stamping of depth and temperature on the video, it’s a nice reminder of the conditions and good for sharing with non-dive buddies to give them a feel for what life is like at different depths. The screens are also well laid out and easy to read, even underwater, which makes checking or changing settings easy.

Generally, I find it extremely useful to be able to just snap it onto my mask and have a recording of my dive from my perspective, without having to be constantly managing a camera or otherwise fiddling; this is my main use case, which impacts how I view the device and the overall review. Another things to note are that I’m not a photography geek and this is my first dive camera, so there may be aspects which you care about that I don’t, and vice versa. The wide angle lens is good, although not a perfect match for human vision, so that’s something to be aware of if you really have to have a specific subject in the video. As I’m specifically focused on the diving and the video is an added extra, I find that I forget about this and, especially on training dives, it can lead to some “so close, but didn’t quite make it into the frame” moments (mostly vertically, I have quite a bit of video of the divers without heads or tanks, which were clearly visible to me at the time). This isn’t a significant concern for me, but may lead you to decide that you need to focus on the camera more than I’m willing to.

Note that the Paralenz is specifically designed as an underwater camera. This has a couple of not-necessarily obvious effects. Primarily, if you’re taking video the above the surface audio is muffled to non-existent. Don’t expect to record anything on the dive boat and capture the witty repertoire. Another aspect is that water tends to bead on the lens when surfacing, so most of my videos of people getting on/off a boat involve a blotch where some water has beaded. If you need that video, make sure you look at the lens and clear any water off it when you surface.

As part of being an underwater camera, it also has built in depth colour correction (DCC). This is good to about 20 meters (after which there’s simply not enough light for the algorithm they use to work). I’ve found it to be mostly decent, although it starts to bleed blue at about 15 meters. Also be aware that any lighting you bring along for the ride will have an impact. White lights cut across the depth color correction as a bright red lightsabre, so you almost certainly want to turn off the colour correction whenever anyone is running lights. Electronic Image Stabilisation (EIS) is mentioned in the manual, but I always use DCC and 2.7K (it’s only good for up to 1080p and mutually exclusive with DCC), so I’ve not really tested it.

Another area of personal preference is the resolution and frame rate. I like to record at 2.7K, 60 frames/second as I find this is the right balance between quality and space (4K isn’t worth it from my perspective, humans can’t really tell the difference at that level and it takes up significant space). Another area where the resolution matters is battery usage. Depending on your dive profile, you might read the 3 hour rated lifetime of the Paralenz+ and think that this is more than adequate for your needs. Keep in mind that the battery life is impacted by several factors though and you’re unlikely to get 3 hours unless you record at 1080p, 30 f/s, it’s been freshly charged within a couple of hours of the dive and you only turn it on once you hit the water (or get to depth). For this reason (as well as some paranoia around it not actually starting), I never use the automatic video recording at depth feature. A more realistic expectation, at 2.7K, is that you’ll get somewhere between 90 and 120 minutes of recording time. It’ll then take 2-3 hours to charge again and the battery isn’t removable, so there’s no short circuiting that. Of course, if your dive profile is one hour dives with at least one hour where you can charge it between dives or you actively manage the camera (only shooting video when you have a specific item to record), this might be of no concern to you at all as you’ll always be able to keep on top of it. The Vaquita has more capacity in its battery, but it also has extra sensors and a previewer in the screen to power, so the battery life is apparently similar.

Speaking of charging, the Paralenz+ has a hardware bug in the USB-C port. The only way to charge it is via a USB-A to USB-C adaptor, if you plug a USB-C charger directly into it, it will fail to negotiate a charging rate with the charger and not charge at all. This has been fixed with the Vaquita, which can properly fast charge on USB-C. Another note with charging is that the display shows a 5-bar bar graph for charging rather than a percentage, so there’s no real way of knowing if you’re at 81% or 99%.

As mentioned earlier, disk space is a concern. In this case, not just disk space, but the type of disk you use is also important as writing high speed files requires a V30 microSD card. Specifically, the Paralenz requires the SanDisk V30 cards (affiliate link) and other brands have had a mixed record. I recommend getting at least 128 GiB as it’s easy to fill less than that on a couple of dives, especially if you’re doing 2.7K or 4K video. You’ll also find that the camera writes files in 10 minute blocks, so that if something goes wrong you don’t lose the whole dive (having said that, I’ve never lost any video from the Paralenz). Metadata is stored in PZAPP files, which are read by the mobile app and can be safely deleted if you’re not using the mobile app.

As far as the app goes, I’ve found it to be nice in theory but has limited use in practice. It takes a very long time to load the video and process it, making showing friends the great video you took quickly via the mobile a non-starter. It’s so much faster to just move the files off the disk and process them on a computer. One are the app does shine though, is making settings changes. It’s a lot easier to do on the app and then just push the changes to the camera. There are also CSV (comma separated value) files recorded with dive metadata, which are quite pretty to bring up in the mobile app and can give you some more insights on your dive.

A final note on usage, the Paralenz runs an embedded Linux installation and is thus incredibly slow to boot (and sometimes take a second to switch modes). If you turn it on, switch to video and attempt to turn on the video mode, you’ll be sorely disappointed (and may miss recording your dive). Make sure that you let it fully boot and show the home screen of the mode you want to select before trying to enable that mode. This can take up to 5 seconds in my experience, so what I usually do is turn it on when I enter the water and then turn on video recording when I start my descent (or, if I’m worried about battery for this dive, I’ll turn it on when I start descent and start recording when I hit depth). I always pull the camera off my mask to double check that video has started recording as I’ve missed a number of dives due to thinking I had the timing right and that not actually being the case.

Feature Requests

While it meets my needs on a daily basis, and I’ve really enjoyed that hands free video allowing me to capture most of what I see without having to manage the camera directly, there are a few features which would significantly improve the Paralenz (yes, I’ve filed feature requests for all of them and if you like these ideas I encourage you to contact support and let them know). I’ve found support to be initially responsive, but actual changes don’t seem to surface from engineering unless it’s a critical bug. There’s certainly some work for them to do in this arena.

Firstly, the view finder. This is added in the Vaquita and will make it much easier to ensure you’re getting the object in question into the frame. I don’t have to do this often, but when I really want to make sure I get a photo (for example, on a boat), it’s a big problem not to be able to tell what’s in frame and what’s not. For this reason alone, I’ll probably upgrade to the Vaquita in relatively short order.

Make the battery replaceable. As with dive torches, it should be easy to make it replaceable and that would make multi-dive recording much easier. This is not currently planned to be fixed in the Vaquita.

Currently, video and photos are mutually exclusive. One of the features of the GoPro is that it can take photos at a regular interval while taking video. Personally, I’d love to have it take a 4K photo every 1-5 seconds while it’s taking 2.7K video. Even better would be being able to flick the switch while taking video to take a photo at that time, without interrupting the video.

Time delayed photos. There’s a time delay option, but it just creates a really horrible video. Much better would be saving individual images at the time delay rate as it’s relatively easy to stitch multiple photos into a video but much harder to extract a decent still from a video.

Automatically detect depth colour correction between blue and green water. I sometimes dive through green to get to blue or dive between the two on the same day and it’s incredibly easy to forget to change the colour correction. This is apparently a significant challenge to auto-detect and is being worked on, but shouldn’t be expected any time soon.

Keep track of last photo/video number. Currently, once the files are removed, it will reset the count to 1 on the next recording. I work around this by making date stamped directories for storing all the media as, obviously, it’ll just overwrite the previous photos/videos if you try and copy to the same directory. As the videos are split into 10 minute chunks, it’s a good idea to split each day/dive into a separate directory anyway just to be able to keep your sanity (and allow for cleaning up the terabytes of data you’re about to collect).

Make it easy to change the WiFi name and password. At the moment, it’s easy to do if you’re technically inclined (there’s a directory on the SD card with the WiFi configuration in it and you just have to edit that). Given that anyone who can see your paralenz over WiFi can connect to it and delete all your photos, I can not stress how important it is to change the password if you use the WiFi features. Having said that, I generally avoid using WiFi as it’s not worth it.

Make a native desktop app. Given the data sizes and the features, it’d be great to have native applications which could really manage it (a mobile app doesn’t cut it for more than a couple of dives, let alone months or years). This will become more important with the Vaquita as it collects a lot more data and scientists are going to want to be able to use it effectively.


The Paralenz is billed as “by divers, for divers”, unfortunately it seems that the software development team is primarily divers and not software developers as the development process has significant flaws.

Areas to be aware of:

  • Firmware updates are posted to the firmware update page, if you’re lucky. The best way to be sure that there’s a firwmare update is to check the mobile app as they frequently fail to update the support page.
  • Firmware release notes need more detail. Frequently, they only say Bug fixes or Optimized and so you’re never quite sure what’s going to change and whether updating firmware (which may bring new bugs) will actually fix the thing that’s annoying you.
  • The mobile app doesn’t show any notes for firmware updates.
  • Straight up bugs. A couple of the more annoying bugs I’ve seen include: the camera reverting video settings on boot; the application removing all depth and temperature data from videos. Always keep old firmware and be prepared to revert if a new bug is introduced that impacts your life significantly. Unfortunately, you’re stuck on the mobile app, which is part of why I don’t use it.
  • The WiFi name changes every time the device gets new firmware. There’s a random number added to the SSID which seems to be regenerated. Yes, this is true even if you make a custom SSID. For example, it might change from paralenz_012D to paralenz_026A.
  • Security is poor. Exposed telnet and plain text FTP, exposing root to the world.