To say that I was excited to hear about the latest firmware update for the S1 Pro Max would be a large understatement! I've always thought this was a nice camera for a variety of reasons (form factor, swivel lens for aiming, the 4k rear camera, and decent image quality out of the front 4k camera), but I found the relatively high rate of video compression to have a detrimental impact on image quality from the forward facing camera when compared to other 4k cameras. This latest firmware update provides a significant update to the video bit rate for the front camera: from 24.6Mb/s to 31.9Mb/s. So, after updating the firmware, I put it back in the car for a quick comparison to the excellent N4 Pro S camera (also 4k, also 31.9Mb/s) and my original Viofo A139 Pro (4k, 45.9Mb/s data rate) camera that I've had for two years.
Both the S1PM and the N4PS have a polarizer installed, both had HDR turned on, both have PlatePix turned on, both have EV = 0.6 to compensate for reduced image brightness resulting from PlatePix. The results are rather interesting!
S1PM Full Frame Image:
N4PS Full Frame Image:
A139 Pro Full Frame: Polarizer installed, HDR on:
And here is a comparison of a 300% crop of the Ford ahead of me while moving at about 30 mph. I timed this each of the images for comparison with CapCut so that the rear wheels of the car have just passed the white line on the road. The three images below were made at precisely the same time and distance from my car.
S1PM 300% crop from above:
N4PS 300% crop from above:
A139 Pro 300% crop from full frame above:
The S1PM still exhibits a bit of a white border outline on certain objects, but it is much reduced compared to images from the previous firmware version. Interestingly, all three cameras exhibit a white halo around the black SUV - this is likely an artifact of the image processing that goes on within each camera related to using overlapping images to create HDR, image sharpening, and other brightness/contrast tweaks that are applied during MPEG encoding. A direct comparison to the N4PS also reveals some compression artifacts that are somewhat more visible in the S1PM than they are in the N4PS - this is most visible in the sky directly above the arm for the traffic lights. It is important to remember that these images are 300% zooms, so the differences are small and I'm being a little picky here. The A139P seems fairly comparable to the other two. Each camera seems to exhibit some digital artifacts as a result of MPEG compression, but these artifacts appear in different areas of the frame. Contrast seems to be a bit greater in the S1PM than in the N4PS, and both are greater than the contrast rendered by the A139P though all produce good images. The image from the A139P is the brightest of the three, but the higher bitrate of the A139P doesn't seem to help it resolve any more detail than the other two cameras in this setting. The A139P also exhibits the greatest color bleed of these 300% zooms, evident directly to the left and right of the SUV.
The rear plate is not readable at all with any of these cameras, but this is not a surprise, the distance was too great for each of these 4k cameras. I'm pretty confident that NO 4k camera (without extra magnification) would be able to read a plate at this distance. The point of this comparison is just to compare overall image quality in the context of the new S1PM firmware update.
Here is another comparison between these three cameras, this time I'm focused on license plate readability. My car is stationary as I wait for a turn arrow. The traffic in the two adjacent lanes is passing by at about 35MPH, so there is a substantial speed differential. All of the same settings apply to both Vantrue cameras: polarizer installed, PlatePix on, HDR on, and EV=0.6.
Full Frame from the S1PM:
And the same from the N4PS:
A139 Pro Full Frame, Polarizer on, HDR on, no EV compensation has been added.
The forum software is telling me that I've reach my limit of images that can be attached to one message, so detailed comparisons are below.
