# What is Sharpness on a CRT exactly?

**URL:** <https://www.retrogameboards.com/t/what-is-sharpness-on-a-crt-exactly/3301>\
**Category:** Video Games\
**Created:** [September 22, 2026, 1:20am UTC](https://www.retrogameboards.com/t/what-is-sharpness-on-a-crt-exactly/3301 "2026-09-22T01:20:39Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Orbitmorning](https://yyz2.discourse-cdn.com/flex036/user_avatar/www.retrogameboards.com/orbitmorning/32/27777_2.png) [@Orbitmorning](https://www.retrogameboards.com/u/Orbitmorning)\
**Post date:** [September 22, 2026, 1:20am UTC](https://www.retrogameboards.com/t/what-is-sharpness-on-a-crt-exactly/3301/1 "2026-09-22T01:20:39Z")

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I was playing with the sharpness setting on my CRT (Magnavox 20MT1331/17) as all my other settings look good. I was using SMB as my adjustment screen (because I’ve played it so much and it’s colorful). And I took pictures of the sharpness on different settings the first one is at 100, then 75, then 50, then 25, then 20, then 15, then the last 2 are at 0. I’ve read that most people recommend 15-25% (that’s why i didn’t 15, 20, and 25). You can clearly see the ringing around Mario on the 100.

What is the sharpening actually doing? And what is the optimal setting for sharpness for NES? Is it 0? I tried my Wii and I had to turn the sharpness up because it was very blurry, but for NES I don’t really know if it matters that much due to the more simplistic graphics.

 ![100perc](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/0/d/0dab0073c0c2594ce83f835bc8232c6db6596610.jpeg)

 ![75perc](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/a/d/ad442dd296342eb363c57886dc01632dc8376f2c.jpeg)

 ![50perc](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/e/c/ecce9147210cf3c6611bfc57039c9078516dedcd.jpeg)

 ![25perc](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/0/9/093575cfcd47aaf864d9ee1828297862977afed9.jpeg)

 ![20perc](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/b/5/b5e860ef8cceda6503df8a4bd6043d17c45b0408.jpeg)

 ![15perc](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/9/c/9cef7c7aabe6ef75e3ada210adf9608fc99712c9.jpeg)

 ![0perc-2](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/e/6/e6d69e73f262db26d5436d9917ee8820a1998397.jpeg)

 ![0perc-1](https://canada1.discourse-cdn.com/flex036/uploads/retrogameboards/original/3X/e/5/e5552fd9a4ff3cec49bcf8e5cc443ca9a8a9488a.jpeg)

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**Author:** ![D.Lo](https://yyz2.discourse-cdn.com/flex036/user_avatar/www.retrogameboards.com/d.lo/32/4116_2.png) [@D.Lo](https://www.retrogameboards.com/u/D.Lo)\
**Post date:** [September 23, 2026, 7:03am UTC](https://www.retrogameboards.com/t/what-is-sharpness-on-a-crt-exactly/3301/2 "2026-09-23T07:03:44Z")

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Good question.

From a quick google I got this:

The sharpness setting on a CRT television adjusts the video amplifier gain for high-frequency signal parts to over-emphasize edges and compensate for detail lost during amplification

**What It Actually Does**

- **Edge enhancement:** It does not add real detail. Instead, it makes light sides of an edge brighter and dark sides darker.
- **The halo effect:** Turning it up too high creates artificial white glowing outlines or halos next to contrasting black lines.

Which makes sense.

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**Author:** ![dubc](https://yyz2.discourse-cdn.com/flex036/user_avatar/www.retrogameboards.com/dubc/32/758_2.png) [@dubc](https://www.retrogameboards.com/u/dubc)\
**Post date:** [September 23, 2026, 3:09pm UTC](https://www.retrogameboards.com/t/what-is-sharpness-on-a-crt-exactly/3301/3 "2026-09-23T15:09:15Z")

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Good article on the CRT Database that goes into a some detail.

> **[What does the "Sharpness" setting do on a CRT? | CRT Database](https://crtdatabase.com/articles/what-does-the-sharpness-setting-do-on-a-crt)**
>
> Table of Contents
>         
> &...

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**Author:** ![Peltz](https://yyz2.discourse-cdn.com/flex036/user_avatar/www.retrogameboards.com/peltz/32/6142_2.png) [@Peltz](https://www.retrogameboards.com/u/Peltz)\
**Post date:** [September 24, 2026, 5:56pm UTC](https://www.retrogameboards.com/t/what-is-sharpness-on-a-crt-exactly/3301/4 "2026-09-24T17:56:47Z")

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I always leave sharpness on zero for every screen I own.
