What is TV Sharpness and How is it Different From TV Resolution?

Learn what the sharpness setting on your TV does

TVs and video projectors provide many settings that aid getting the best picture quality based on the TV's capabilities, or according to your own preference. Among these settings are sharpness controls and resolution settings, which are not the same. Keep reading to learn about TV sharpness and resolution and how they affect your televisions image quality.

This information applies to TVs from a variety of manufacturers including, but not limited to, LG, Samsung, Panasonic, Sony, and Vizio as well as video projectors made by manufacturers such as Benq, Epson, and Optoma.

Samsung Picture Sharpness Setting

Sharpness vs Resolution

The common perception of Sharpness (as used in video applications) is that it's directly related to resolution and that a sharpness control increases the resolution of an image. However, that is not the case. 

On today's TVs, the resolution refers to a fixed number of pixels (720p, 1080p, 4K, 8K). The resolution of a source connected to a TV may be lower, but the TV (or projector) upscales the image so that it's displayed using the number of allocated pixels on the TV screen. 

Sharpness, on the other hand, is a control that increases edge contrast so that objects become more distinct, but the image resolution remains the same. This means that while the sharpness setting makes the image appear to have more detail, it actually doesn't. 

Benefits of Using the Sharpness Control

  • If you have an image that appears "soft", using the sharpness control in small steps can make the object edges more distinct. 
  • With lower resolution images that have been upscaled, applying a small amount of sharpness, the edges of the image may make objects look more distinct on a higher resolution TV. 
TV Sharpness Comparison Example – Low Setting
Image on left shows a normal sharpness setting while on the right has the sharpness setting increased slightly.

Pitfalls of Using the Sharpness Control

  • If the sharpness is pushed too far, it can result in halos and/or rough edges around objects. If the picture source is noisy (film grain, source noise in analog video, TV broadcast noise), those effects will become worse as the edges of the grain and noise will be emphasized.
  • As a result of adding too much sharpness, objects will appear to have coarse edges, giving the overall image a harsh look.
  • The harshness also affects other elements of the image, such as contrast, brightness, and color. This results in an overly "pasty" look on faces and the texture of background objects although looking "3D-ish", actually become more distracting. You may also notice previously hidden small macroblocking and/or pixelation issues. 

Click on the image below to view the sharpness comparison larger so that the difference is more visible. The image on the left is "normal" while the image on the right is overly sharpened, resulting in harsher edges.

Seattle Skyline – Normal vs Sharp
Left image shows a normal sharpness setting while the right is overly sharpened, resulting in harsher edges.

Other Setting Options Similar to the Sharpness Control

If you find images from specific sources look too soft, even on a 1080p or 4K TV or video projector image, other setting options that provide more precision than the sharpness control are Detail (aka Edge) Enhancement and Noise Reduction (aka Digital Noise Reduction or DNR). 

Picture setting presets combine several parameters that determine how images should look on a TV or video projection screen based on specific content or room lighting conditions.

These controls don't change the actual resolution of the image as that is determined by the source in combination with the number of pixels on the TV screen. 

However, carefully implemented in small steps, detail/edge enhancement can fine-tune soft edges. Also, using small steps in the noise reduction setting can reduce halo effects or added noise, such as film or broadcast grain, and some of the harsh effects that might be brought out by the detail/edge enhancement setting.

You may still run into a situation where the image displayed will take on a pasty look that may not be much better than when you tried the more basic sharpness setting. You may also find that a source may have edge enhancement already applied (common with some DVDs and Blu-ray Discs). In these cases, using the TV's sharpness or detail/edge enhancement/noise reduction may make things worse. 

Some DVD, Blu-ray, and Ultra HD Blu-ray players have their own sharpness/detail/edge and/or noise reductions settings. Refer to the example below.

Sharpness and Noise Reduction Settings – OPPO UDP-203 UHD Blu-ray Player

What Other Picture Controls Do

  • Brightness: Makes dark areas brighter or darker.
  • Contrast: Makes bright areas brighter or darker.
  • Color: Increases or decreases the saturation (intensity) of all colors in the image together.
  • Tint (Hue): Adjusts the amount of green and magenta in the image (used primarily to dial in better skin tones).

The Bottom Line: Use Caution When Using the Sharpness Control

TVs and video projectors provide a lot of setting options to maximize picture quality but use caution when using the sharpness control. 

Too little sharpness makes the picture appear soft while too much sharpness makes the picture look harsh. 

  • The sharpness control gives the TV/projector user the false impression that it will increase or improve the resolution of the TV's image. However, not only does it not increase resolution, but can add undesirable effects that can make the image look worse if applied incorrectly. 
  • Check your TV or projector's default settings. It is best to leave the default setting for sharpness alone or limit your changes to one or two steps up or down.  
  • If you want to experiment with the sharpness or detail/edge enhancement/noise reduction settings, take note of their default position so you can return to that point if you decide your changes don't look good.
  • You may find a specific source needs a slight sharpness adjustment, but others don't.
  • On many TVs, you can apply different picture setting preferences, including sharpness, to each input. This means that if you need to change the sharpness setting where it may be needed on one input, but the other sources connected to other inputs are fine, this means you don't have to make repeated changes for all your sources.