Great question and thought I would weigh in with my thoughts on this one.
Personally, having tested and used a number of 4K cams, most, definitely have the edge during daytime as they don't have to compromise their image with processing for sharpness, extra contrast etc (in most cases). Nighttime is a different story and with installs that involve locations with great lighting (fair and good is not enough) they do a good job, but generally still in B&W to be successful. For color at night with 4K you need well balanced light and a lot of it still if you want blur free, usable caps especially at mid to edge of the FOV.
Most installs will never benefit from 4K color at night
at the moment BUT cams and sensors are getting a lot better with regards to the pairings and their resulting light sensitivity. If people do ask me for a 4K turret or bullet cam recommendation, my personal favorite (if you have to have 4K) is still the 4K (8MP) 2831 bullet cam (original version, IPC-HFW2831T-ZS) as the image and performance in my testing has the edge overall against the 5831. Worth noting there are of course differences between the 2831 and 5831 (1/1,8" vs 1/2.5" sensor, 25/30fps vs 15fps and different aperture optics that combined with the sensors produce light sensitivity at 1/30 of 0.09 @ f1.9 on 2831 vs 0.2 @ f1.4 on 5831).
My advice for others here is again
IF you absolutely want 4K then consider a mixed environment, have areas where you can have a 4K and 'other' (2MP, 4MP like the great 5442) cams covering the same area (from different directions). Daytime will give you the benefit of having more image to work with on the 4K but the 5442 gives a great image too and is more of an all rounder enabling it to be more flexible to your install location. At nighttime, If you have enough light for good 4K B&W then you will certainly have enough for amazing B&W &
potentially full color from a 5442, therefore they
can compliment each other and add to your overall system. However I'll reiterate the cautionary tale that I and others have stated many times, don't chase megapixels (made a post on this
HERE). I still hear from a large number of people that believe 4K is the solve all for their install and this is almost always not the case. Better off with a mix of cams like the 5442 to suit the needs of the location, install and lighting. Also remember, never use AUTO, always manually dial in your cam
With regards to the 5442 daytime image, as
@spammenotinoz mentioned, the 5442 series has always featured a more 'processed' look out of the box but luckily that can be dialed in as well to suit. The 5442 cams including this great new vari do give those on the fence about upgrading from a 5231 or just wanting to step up to 4MP a great reason to do so
HTH
You think the new camera has better day time pic than the 8MP one?
Nightvision will be bit good, you can test hours later this night.
No, the 8MP IPC-HDW5831R-ZE has great day pics, and good at night (manually dialed in). Auto at night doesn't suite my layout due to the overlapping cams.
The T5442T-ZE pictures appear overly sharp during the day, which is not as pleasing to look at as the 4K. That being said on the limited daytime I could make out license plates, so certainly not disappointing.
That being said, this isn't hollywood so it's about what detail I can capture v's visual appel.
Tonight I will leave it in colour, but suspect I will need more light to make out people in the distance, but already it's a major step up in identifying moving vehicles at night.