These are the settings we used to calibrate the 55" TCL S517 (55S517), and we expect them to be mostly valid for the 43" S517 (43S517), 49" S517 (49S517) and 65" S517 (65S517) and all sizes of the Best Buy S515 variant. These setting are good for most content, from TV shows to movies and gaming. For gaming, some minor changes are needed to have the best input lag, and they are listed below.
We used the Movie picture mode to get as close as possible to our calibration goal. The Picture Size was left to Auto since under this setting, the TV will adjust the picture size to match the screen size by itself.
The TCL S517 uses two separate settings to control the overall brightness. The TV brightness setting allows you to set the range of brightness of the TV, from Darker to Brighter. You should choose the option that most closely represents your viewing conditions, i.e. Darker for a completely dark room. The Backlight setting is then used to more finely tune the TV's brightness. Both of these settings have no impact on picture quality. For our calibration target of 100 cd/m² we set the TV's brightness setting to Darker, and the Backlight setting to 79. Almost everyone will find this too dim, and you should adjust these settings.
In the Advanced picture settings, Micro Contrast and Dynamic Contrast were left off, as we don't want the TV to change the contrast during our testing. Contrast was left at 100, and Sharpness was set to 0 so that no oversharpness is added to the original content. Color was left to 45 and Tint to 0, their default values. The Color temperature was set to 'Warm' since it is the color temperature the closest to our calibration goal, but you can set it to a colder temperature if you find the screen to be too yellow or red.
The TCL S517 features a new option to help motion appear smoother. The first option is called Action Smoothing, which is TCL's name for motion interpolation. We recommend leaving this setting off, but if you find lower framerate content looks choppy (stutter), you can enable it, in which case the TV will interpolate extra frames to increase the framerate up to 60 Hz. Natural Cinema is the option which enables the TCL's judder reduction feature. We leave it off for our calibration, but turning it on will remove judder from 24p content (movies usually) played from non native-24p sources such as a cable box, or even from the built-in apps.
If you intend to watch HDR content via an HDR UHD Blu-ray player or via an HDR video game console connected via HDMI, you will have to set the HDMI mode to HDMI 2.0 for the port used. This option is situated in the TV inputs menu and has to be set for each of the 3 HDMI inputs. It is generally okay to leave it on HDMI 2.0 for all ports, but some older devices might not work properly. For HDR content, the TV will change picture mode to match the type of HDR content (Dolby Vision or HDR10) by itself, but if you want to be sure you have the best setting, just verify that the TV brightness is set to the Brighter setting, that the Backlight is set to maximum.
For playing video games in SDR or HDR, via video game console or PC, simply turn on Game mode from the Advanced picture settings menu to have the best input lag possible. It should also be enabled when the S517 is used as a PC monitor.
There are no special settings for use as a PC Monitor. The TCL S517 automatically detects when it is connected to a PC and will choose the settings which offer the lowest input lag possible. This includes disabling all image processing features. If the TV doesn't automatically detect that it is connected to a PC, setting the input label to Computer will automatically put the S517 into PC Mode. Even in PC mode, Game mode must be enabled to get the lowest input lag possible. When in PC Mode, the sharpness setting does nothing, it is not possible to enable add sharpness.
There are some settings that are only available via the mobile Roku apps. The Roku app is compatible with iOS and Android devices and can be downloaded via either the Apple App Store or via Google Play store. For more in for on the Roku app itself, you can access this page. To access those setting, you need to go to the 'Setting' tab, and then go to 'Expert Picture Settings'.
In the Expert Picture Settings menu, you can set the Picture mode, Gamma, Noise Reduction, Color temperature, the 11 points White balance calibration and the Color Space calibration. Some settings like the picture mode and color temperature are redundant and don't need to be changed again if already set from the TV settings. For our calibration and to get the best picture quality, set the Gamma to 2.2. If you are watching SDR or HDR content and you find that you are losing too much detail in the dark areas of the screen (black crush) or the white levels(clipping), you can change the gamma value to a lower or higher setting. We also set the noise reduction to off. This can be turned on if you are watching some older low-resolution video since it can help to reduce compression artifacts often present on older content. If you intend to do a calibration, then you will need to change the value in the 11 Pt WB (the white balance control) and change the Color Space setting to Custom and change the value for each color. Note that each color temperature has separate calibration data, so if you calibrate on the Warm color temperature, your correction won't be applied if you change the color temperature to another one.
The following are the results of the white balance and colorspace calibration on our unit. They are provided for reference, and should not be copied as the calibration values vary per individual unit even for the same model and same size as the TV we reviewed due to manufacturing tolerances. If you want to try them you will need to enter all values shown, as all of them are active at the same time. If you end up with worse picture quality, simply reset them to the default values.