TCL C75B offers various picture modes, but in our opinion, the best choice is the “Film” mode. Although its settings are quite decent, the TV struggles with certain colour reproduction issues. In tests, we noticed that the image had a noticeably pinkish hue compared to what could be considered correct. This effect was particularly evident in skin tones, which appeared unnaturally flushed. The main culprit of this phenomenon turned out to be the white balance, characterised by an excess of blue and red in both HD and 4K HDR materials.
An additional problem was the way brightness was reproduced. The gamma, which is responsible for the visibility of details in darker materials, was definitely boosted, causing details in the darkest parts of the screen to be invisible, disappearing into complete black (e.g., the bottom part of the screen in the comparison image - the area around the actress's ear). The situation was similar on the EOTF curve, which was below the correct value, suggesting that a similar issue may be encountered in 4K HDR content.
Thanks to our experience and the appropriate tools, we decided to take matters into our own hands and check how much could be extracted from this model after professional calibration. The details are described in the next section.
In Film mode the TCL P7L performs quite decently without major tweaks, especially with ordinary SDR material. The white balance is relatively even, although as brightness increases there’s a slight rise in red and blue and a bit too little green. That doesn’t create a strongly visible colour cast and most colours remain close to their reference points. The Colour Checker confirms this, with a large portion of errors falling below the level that should particularly bother during normal viewing. We have more remarks about the gamma response. In the darkest parts of the image the TV drives it noticeably above the reference, so some shadow detail may be a little too dim. The curve then settles and for much of the range it’s close to the intended targets. As a result SDR generally looks natural, but in dark scenes the P7L can lose some subtlety.
In HDR the factory setup is less precise. As brightness increases the excess blue becomes more pronounced, so the picture can look cooler than it should. The number of larger colour deviations also rises, especially in brighter colours. The EOTF curve itself is handled fairly conservatively, with the TV showing the image darker than the reference over much of the range. For such an inexpensive model, the factory Film mode settings are not bad.