Purchased as an upgrade from the DJI Osmo Action 3 mainly because the OA3 struggled with nighttime videos and lately I do or complete half of my routes during the evening hours.
Package contents:
Camera, selfie stick with a 1/4" screw socket at the bottom (lighter and slightly longer than the selfie stick of the Action3), charger with 3 batteries, 2 quick-release adapters (with slightly less powerful magnets than those of the Action3), along with 2 screws, 1 adhesive mount, 1 plastic frame, 1 cable, and 4 anti-slip stickers.
Construction/Software stability/Overheating:
Sturdy, small, same dimensions as the OA3, with minimal differences in colors and the description of the sensor and lens on the screw-on lens protector. The feel in hand is that it doesn't break as easily and, judging by my experience with the OA3, this is true. In short, if the old good NOKIA made cameras, these would be the OA3 and OA4.
The camera is waterproof up to 18 meters, which I believe is also the top performance for action cameras of this generation.
The magnetic contacts of the quick-release mechanism for both the camera and the clip seem to have less strength. They remain quite strong, but do not require the same force to detach from each other when you press the two hooks of the clip. Anyway, they scare me a bit, and I use a special frame from SmallRig to be more sure.
So far, the camera has not frozen even once, although on its maiden trip from Ioannina to Athens via Kalambaka and E65 (https://www.youtube.com/watch?v=u79Eh1H21rM) it was in operation with 3-4 five-minute breaks for battery changes for over 6 hours.
Since I haven't had the chance to use it indoors with little or no airflow yet, I don't know how it will behave, but on spring routes with the camera outside the car, it hasn't overheated, which is quite logical and expected.
However, I believe that the European model continues to shut down much earlier than the American one due to EU legislation (paradoxically, GoPro and Insta360 fry an egg before shutting down, while DJI is lukewarm when shutting down from overheating).
Video quality and stabilization day/night and video sound quality:
The larger sensor (compared to the OA3) offers greater clarity in video and superior image quality at all hours. With the OA4, DJI ensures to improve an already successful recipe and does not try to experiment more than necessary, so the maximum resolution is 4K and the maximum frame rate at 4K is 120fps. That is, just as it was with the OA3.
The OA4 offers the widest lens (155 degrees) on the market without the addition of any extra (GoPro, I'm looking at you) and has, I believe, the lowest image distortion among the 3 flagship action cameras of this generation (GoPro Hero 12, DJI Osmo Action 4, Insta360 AcePro).
It has horizon steady to keep the shot level up to 45 degrees and generally excellent video stabilization.
In nighttime videos, it leaves the GoPro Hero 12 behind, but shows a bit more ghosting compared to the Insta360 AcePro, so I believe it will satisfy everyone except the most demanding of nighttime videos.
Regarding sound quality, I might be wrong, it might just be my impression, but I feel that it is slightly inferior to that of the OA3.
Photos:
It takes very nice photos at 10MP and has a rudimentary digital zoom. I don't know if it will help you win an award in a photography contest, but if you don't have particularly high demands (epic zooms and I don't know what else), it will definitely meet your needs, and it also has the capability to take RAW photos for even greater freedom in editing.
Timelapse/Hyperlapse:
It is very reliable in Timelapse functions (static long shots, e.g., on a tripod) and Hyperlapse (moving long shots, e.g., in a car), and if someone knows about custom settings and editing through special programs, they will definitely produce very commendable night Timelapses. However, I haven't found a specific function like Nightlapse/Starlapse/Startrails, etc., like the GoPro Hero 12 and Insta360 AcePro have.
Battery Life:
I didn't notice a difference in operating times between OA4 and OA3, but as everyone who has tried the DJI OA4 or OA3 can tell you, these two cameras have by far the best energy management, resulting in over 1.5 hours of continuous video recording at 4K@25.
Mobile/Tablet App:
As has been customary in recent years, the first activation of the camera requires a connection to the DJI Mimo app. Comparing DJI Mimo with GoPro Quik and Insta360 app, I notice that it is generally the slowest of the three in startup from the main screen, in loading icons, and in connecting to the camera, but it is very stable in all other aspects and offers a very decent live feed from the camera even after disconnecting and reconnecting the app (I can't say the same for GoPro).
In Summary:
A very commendable camera, compatible with all accessories for DJI Osmo Action 3. The videos are excellent during the day and very good at night. The other functions are useful, the app is reliable, the build is sturdy, and its battery is top-notch among flagship action cameras. A significant drawback, in my personal opinion, is the quick release system, which does not inspire much confidence when used on a moving vehicle with the camera exposed to air and vibrations, and the lack of additional night functions like Nightlapse, etc. If you are thinking of buying a camera now, it is a very good choice. If you are considering upgrading from Action 3, the only reason is the much better night video.
Since I have been using it extensively lately, you can see more videos on my channel (IF I manage before the Action 5 comes out, I might upload a review video):
youtube.com/@TravellerChris