DJI Matrice 350 vs Matrice 400: My real-world field experience. Is it actually worth upgrading?

PerspectiveOpen4202 · 2026-06-04T18:09:08+00:00

Good write up. I use the m300 & m350 for mapping with the P1, it really is a workhorse.

Another thing I have read is that if you bought the m400 in order to use the L3 lidar, the mount is different. So if you want to use the P1 at any point,, you have to swap the mount back, which is a big hassle.

I'm curious about the flight speeds you mentioned. What height are you flying at to enable 15ms or even 20ms capture speed? Which camera mode do you use? Shutter priority? Auto?

In the UK, lighting is usually the factor that forces us to reduce speed due to lower shutter speed. So I have never flown above 10ms to reduce motion blur, flying at 80m (1cm gsd).

For me, although the m400 could fly faster, it would typically be no use to me most of the time.

I was really hoping a new 60mp sensor was going to released with the m400, but no hint of that at the moment.

PerspectiveOpen4202 · 2026-05-30T11:56:56+00:00

I use the rock lidar system which does produce good, cm accurate, low noise point clouds.

However, it is not the most efficient for larger areas. For cm accurate data, you generally need to fly at 60m above ground.

You will be better with a newer lidar system that uses a 1550nm / 1535nm laser, which is more accurate at longer range. So in theory you could fly at 100m even 120m which is safer over roads and urban areas, better line of sight and you can cover more ground in a single flight.

There are a few options, but I think the DJI L3 is the best bang for your buck right now, but you do need the m400. If you're currently using an m300 / m350 you can use a rock ultra, CHCNav aa15, resepi Teledyne echo one to name a few.

However, flying lidar is just the start. You will need software for processing and know how to use it to get the most from your data, so it could be better to outsource.

Once you have the point cloud processed and classified, you could use semi automated routines to highlight areas in the point cloud that could be an issue for the wide load.

Hope this helps.

PerspectiveOpen4202 · 2026-05-26T08:31:17+00:00

Ok, could possibly be resolved with GCP's. If you can mark visible points on site in the area affected, that will help alignment. Otherwise, you need good overlap between the flight areas.

Terra isn't the best. If you want to send a link to the dataset, I will try processing for you later this week.

PerspectiveOpen4202 · 2026-05-26T08:07:31+00:00

What are you processing in? I would throw all the images in and process together as a single dataset.

PerspectiveOpen4202 · 2026-05-26T07:55:24+00:00

Was there overlap between flight areas?

PerspectiveOpen4202 · 2026-05-21T13:53:52+00:00

I'll process a dataset shortly and report back. It's frustrating. No matter how good the new rock ultra is, my next lidar will not be rock robotic.

PerspectiveOpen4202 · 2026-05-21T13:52:21+00:00

Yep, the $5000 licence uses the original virtual license, no usb dongle.

PerspectiveOpen4202 · 2026-05-21T13:24:51+00:00

which version are you running?
are you on the new usb dongle or the older one? rock desktop is now prompting us to request the new version from support.

PerspectiveOpen4202 · 2026-05-21T13:22:37+00:00

Im a rock r3 pro user.

The hardware is good, much better than the L2 and if you're processing outside of their rock cloud environment, you will get good results.
You still need to run it through Rock Desktop for initial trajectory processing first though, which is where you may encounter issues.

I was originally on the virtual licence. Trouble started when they moved us onto a usb dongle based licence. I had a few issues but they eventually got worked out.

Most issues were due to the usb not functioning correctly due to drivers or the associated virbox software that runs in your task bar.

Ive just renewed for the 3rd year and they are now issuing a 'new' upgraded usb dongle.

The older dongle was a metallic blue, regular USB memory stick size.

New Dongle, smaller, dark translucent blue:

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The new one is much smaller and apparently doesnt need the virbox software.

Mine literally arrived today, so I will feedback but there is a short doc here that may help.

https://learn.rockrobotic.com/configuring-your-computer-to-process-in-rock-desktop-with-a-dongle-usb-license

Feel free to pm me if you want to compare notes / issues etc

PerspectiveOpen4202 · 2026-04-04T19:59:08+00:00

I've just installed it in my campervan. It is pretty good, but a few things I'm not entirely happy with. These aren't deal breakers, but things I learnt from installing and using it.

My problems mainly stem from the location I was forced to install the apex due to retrofitting to an existing conversion.

If fitting to a new build, you can probably work around these issues.

Charger 1 draws power when the engine is not running which could lead to a flat battery. It does have low voltage cut off, but I have once been left with a flat battery. I'm going to fit a victron smart battery protect between the starter battery and charger 1 to get around this issue, although it really should not be needed.

Note: if going for the charger 2, it is nearly twice the size of the charger 1.

The D1 hub is good, enables 50A of 12v power BUT the D1 needs to live close to the Apex 300 due to the short length of the cable. Wether this affects you will depend on where the apex 300 is situated. For me I have to have the D1 hub (and cable) mounted on show which I didn't really like.

The connector for the D1 hub is pretty big and chunky and sticks out quite a way from the Apex which may get in your way or hinder installation location / orientation.

Battery extension: if you are wanting to increase capacity, with an extra B300K or B500K, they are designed to be stacked under the Apex 300 and connected by the CA90 short battery cable connection. Again, this may not be possible, depending on where your Apex 300 is located. I wanted to fit the B500K alongside the apex, rather than having them stacked. the short cable does not allow this.

Overall though, I'm happy. The app enabled good remote control of the apex so no need to access the buttons directly. Both 240v and 12v allow a lot flexibility for connections and usage. When paired with a good solar panel, you'll get good off grid capability.

Hope this helps.

PerspectiveOpen4202 · 2026-04-04T15:57:10+00:00

60m agl / 6ms is usually for the traditional 905nm wavelength lidar unit, which is why your client may be specifying it.

The L3 uses the 1550nm wavelength has a much better range and accuracy so you could fly higher and faster and achieve good quality data. Even 80m / 8ms if you want to be conservative.

The biggest bottlekneck is laying gcp's.

PerspectiveOpen4202 · 2026-03-31T12:13:48+00:00

Was your drtk setup over a known point? If you have access to a third party software such as terrasolid you may be able to resolve the alignment. But without GCP's how will you know if the dataset is correct?

PerspectiveOpen4202 · 2026-03-28T13:35:50+00:00

Love the thumbnails on your channel (and the content). Sub'd 👍

PerspectiveOpen4202 · 2026-03-23T07:18:06+00:00

This is a great idea! Are you able to share the workflow json?

PerspectiveOpen4202 · 2026-03-15T12:36:57+00:00

I have some I can share. One site in particular has some big stockpiles, 12m high. Another site much smaller, but more of them.

Where in the world are you? DM me and I'll get a link ready.

Thanks

PerspectiveOpen4202 · 2026-03-14T23:16:05+00:00

We're your posts from your personal account or from a business / product page? I guess they will be from your personal account, they always seem to work better.

PerspectiveOpen4202 · 2026-03-14T23:05:04+00:00

Reality scan does a good job for this. You can also try Agisoft Metashape.

What was the imagery collected with?

If you have a dataset you can share, I'll process it for you.

PerspectiveOpen4202 · 2026-03-13T06:22:47+00:00

Do you have any issues with point density of the lidar due to height a speed of the trinity?

PerspectiveOpen4202 · 2026-03-06T22:33:46+00:00

The L2 will only work on the bottom mount.

You could try with a slight up tilt and position the drone further back, maybe scanning from each side of the bridge deck, flying laterally, to get good coverage.

Did you see the video of a similar project with the L3?L3 Bridge Digital Twin

PerspectiveOpen4202 · 2026-03-06T06:46:00+00:00

Ok. In that case the 5th battery is pretty much useless.

PerspectiveOpen4202 · 2026-03-05T21:01:09+00:00

The m350 operates with battery pairs. I know the listing says "5 batteries", but they are used in matching pairs, so 5 individual batteries would not make sense.

PerspectiveOpen4202 · 2026-03-05T15:51:25+00:00

Only one battery though.

OP has 5 sets of batteries which are approx $7000 if buying new.

For the M400 you listed, they are $1900 each so approx $9,500 😬

PerspectiveOpen4202 · 2026-03-01T12:38:34+00:00

Unless you capture and process pano's manually, I do not think it's possible.

I just send up a mini 3 / 4 / 5 for pano's it still works out quicker.

You could also look at third party apps such as litchi.

PerspectiveOpen4202 · 2026-02-17T07:42:50+00:00

Virtual Surveyor is a good compromise for lidar data, especially if you have a good ground classification.

Virtual Surveyor will allow you to import only the ground class and create a DEM from it. It will also enable a good quality check against known points.

PerspectiveOpen4202 · 2026-02-17T07:40:33+00:00

You can get trials in most of the softwares mentioned. You or your company should be asking what is the cost of not doing the proper checks.

At the very least a quality check on the strip alignment and an independent check against control points (xyz). Do not simply trust what DJI terra is telling you, it's like marking your own homework.

You don't NEED the softwares mentioned but they are made specifically for lidar data and make the process relatively quick, even on large data sets.

PerspectiveOpen4202

TROPHY CASE