OLED65C7P vs OLED65E7P

The LG OLED65C7P and OLED65E7P differ only in that the OLED65C7P omits the Picture-on-Glass design and the integrated sound bar of the OLED65E7P. The picture quality, however, is identical.

Design: Picture-on-Glass (OLED65E7P) vs Blade Slim (OLED65C7P)
The ultra thin OLED module on the OLED65E7P is mounted directly on a glass back panel, hence the Picture-on-Glass design. The OLED65C7P, on the other hand, has the so-called Blade Slim design. As the name suggests, the OLED module is still extremely thin but the rear panel is not made of glass. As a result, there is no translucent frame around the screen on the OLED65C7P; instead a minimal black bezel can be found. But just like the glass frame around the screen of the OLED65E7P, the bezel on the OLED65C7P won't distract your from the picture, especially under light controlled conditions.

Stand: The OLED65E7P sits half an inch lower than the OLED65C7P when mounted on a table top surface
The OLED65E7P and OLED65C7P utilize a type of trapezium stand. Although both the material (aluminum) and the color (silver) of the stand that is included with the two TVs are identical, there is a difference in the height the OLED65C7P and OLED65E7P sit at. In particular, there is a clearance of approximately 1.6 inches beneath the bottom edge on the OLED65C7P whereas the integrated sound bar on the OLED65E7P sits at about 1.1 inches above the table top surface. You can also mount the OLED65C7P and OLED65E7P on a wall using VESA 300x200 compatible bracket.

Sound: 4.2 Channel Integrated Sound bar (OLED65E7P) vs 2.2 Channel Down-firing speakers (OLED65C7P)
As previously mentioned, the OLED65E7P has an integrated sound bar for housing a 4.2 channel speaker system. The total audio power output on the OLED65E7P is 60 Watts, a third of which (i.e. 20 Watts) is being allocated for the subwoofers. The front-firing speakers allow the OLED65E7P to project voices and dialogues more clearly than the down-firing speakers on the OLED65C7P. The total audio power output on the OLED65C7P is 40 Watts which is lower than the OLED65E7P. However, once you've taken into account that the speaker system is 2.2 channel on the OLED65C7P, it becomes apparent that the two TVs don't differ in terms of amplification per channel (the OLED65C7P also delivers 20 Watts to its subwoofers). However, the OLED65E7P has two extra channels when compared to the OLED65C7P. Both TVs have a Dolby Atmos decoder, so you can either listen to Dolby Atmos sound tracks via the internal speakers on the OLED65C7P and OLED65E7P, or bitstream Atmos tracks to a compatible receiver.

Image Quality: The OLED65E7P and OLED65C7P have the same black level and peak brightness with SDR content
Since the OLED65C7P and OLED65E7P both are self-emissive displays (which is characteristic of OLED TVs), they have the ability to turn off individual pixels when displaying black color in order to achieve a perfect black level. In other words, there is no difference in terms of minimum luminance level on the OLED65C7P and OLED65E7P. On the other end of the brightness scale, they are also identical since both the OLED65C7P and OLED65E7P are able to reach approximately 150cd/m2 on a full-field white (100% Average Picture Level). The reason for that is they have the same generation OLED panel, and the ABL, or Automatic Brightness Limiter, behaves identically on both of them - once it starts to function at above 150cd/m2. This threshold is not randomly chosen, however. Instead, it's purposefully set in order for the OLED65C7P and OLED65E7P to be able to achieve a reference image quality, at least under light controlled conditions, with SDR content which is typically mastered to 100cd/m2.

On both the OLED65E7P and OLED65C7P there is plenty of headroom for making the image brighter, at least with low to mid APL content
As previously said, the OLED65C7P and OLED65E7P are able to meet and exceed the brightness level SDR is mastered to, even with high APL (Average Picture Level) content. That being said, if you'd like to watch hockey (or other content with preponderance of bright elements) under high ambient light conditions, it'd most likely be necessary to increase the brightness level on your TV. The headroom on the OLED65C7P and OLED65E7P for making the overall image brighter varies with the APL of content because of the Automatic Brightness Limiter (ABL) on the OLED65C7P and OLED65E7P. Generally, the ABL lowers the brightness as APL increases, and vice versa. Nevertheless, there is more than enough headroom on the OLED65C7P and OLED65E7P for making the image brighter even when the SDR content has 50% APL in which case the peak luminance on the OLED65C7P and OLED65E7P is circa 350cd/m2. Although this decreases to 150cd/m2 as the APL goes from 50% to 100%, it needs to be said that SDR content with high APL, apart from hockey and some winter sports, is rarely encountered, so the ABL seldom poses any significant drawback. Furthermore, the vast majority of movies and TV shows have low to mid APL level, so they are impacted even less by the ABL than high APL content. For example, the two TVs are able to reach approximately 430cd/m2 with either 10% or 25% APL, thus leaving you plenty of headroom for a brightness adjustment, should the ambient lighting require you to do so. If you calibrate either the OLED65C7P or OLED65E7P for 150cd/m2 or less, you don't have to worry for ABL at all.

Identical HDR format support and performance
The peak brightness on the OLED65C7P and OLED65E7P in small specular highlights is about 720cd/m2 (10% window size) when D65 white point is used. HDR differs from SDR in that only specular highlights are rendered brighter (instead of the overall image) for the purpose of increasing the dynamic range, hence the name. The OLED65C7P and OLED65E7P support the HDR10, Dolby Vision and HLG formats out of the box. HDR10 content is mastered to either 1,000cd/m2 or 4,000cd/m2. The OLED65C7P and OLED65E7P are able to resolve detail up to 4,000cd/m2 through tone-mapping. It needs to be said that they will, by default, attempt to do so with every scene, regardless if highlights are present or not in the HDR10 content. Therefore, unless you use the Active HDR processing the OLED65C7P and OLED65E7P are equipped with (for the purpose of dynamically optimizing HDR10 content), the two TVs will render some of the mid-tones in scenes without highlights slightly darker than optimal. This is a side effect of the way the OLED65C7P and OLED65E7P are programmed to track the PQ (Perceptual Quantizer) function, on the one hand, and the fact that the static metadata in HDR10 defines maxCLL (maximum content light level) which remains unchanged for the entire duration of the HDR content, on the other.

Wide Color Gamut: ~99% DCI-P3 for both the OLED65C7P and OLED65E7P
Color reproduction is also extremely important for HDR content. There is no significant difference between the OLED65C7P and OLED65E7P in terms of wide color gamut since they cover approximately 99% of the DCI-P3 color space. Only some of the brightest highlights exhibit less than optimal color saturation. Further, the OLED65C7P and OLED65E7P are capable of displaying over billion color shades thanks to the 10-bit panel they utilize. This enables smooth color gradation, without any banding.

Motion, gaming and Smart TV system are all identical on the OLED65C7P vs OLED65E7P
The native refresh rate is 120Hz on both of them, meaning there is no judder with 24p content. The nearly instantaneous pixel response time, and the motion compensated frame interpolation, which you can adjust to your liking, make the OLED65C7P and OLED65E7P suitable for watching sports and action movies. The input lag is approximately 21 ms with either 1080p or 4K signal. The smart TV platform is webOS 3.5 on both of them. The Magic motion remote on the OLED65E7P, however, differs visually from the OLED65C7P's magic remote in that it's slightly thinner and longer. However, the point-and-click functionality, as well as the built-in microphone and scroll wheel, are the same on both versions of the Magic remote.