Is the stroboscopic effect amplified by sharpening filters?

[MoinWoll]

Hi guys,

first I'd like to say this site taught me so much about display technology and visual perception - it's incredible. Thank you!

The topic I'd like to discuss is the influence of sharpening filters on (the perception) of the stroboscopic effect.

Roughly around the time I upgraded from the LG 24GM77-B (24", 1080p, 144Hz, TN) to the LG 27GL850-B (27", 1440p, 144Hz, IPS, Adaptive Sync) I started to notice the stroboscopic effect, especially in fast paced shooters like Doom Eternal. With the 24GM77 I never seemed to notice it, at least I wasn't bothered by it. It seemed that the bigger, higher-resolution and slightly slower 27GL850 made it more visible. However, when comparing them side by side, I could also observe it on the old monitor, maybe a bit less, but enough to make me curious what else could have influenced my change in perception.

I tried many different display and graphics settings and came to the conclusion that sharpening filters, like the one in the Nvidia driver settings, amplify my perception of the stroboscopic effect to a point where it becomes really annoying. I only started using sharpening relatively recently to counter the awful blur from temporal anti-aliasing almost all games use nowadays and can't go without it anymore. Motion Blur lessens the the stroboscopic effect somewhat, even when using sharpening, but this is a rather makeshift solution, since it reintroduces blur, albeit a different kind.

Now to my questions:
Can you confirm, that sharpening filters do in fact amplify the stroboscopic effect, or am I just imagining things?
What are the physical reasons for this behavior, if it's true?
Is there any other way to counter the effect aside from increasing motion blur?

I'm looking forward to hearing your experiences and answers!

[RealNC]

The effect is more visible because the display is larger, not because it's sharper. The effect is the result of gaps between the same objects in successive frames. As you can imagine, that distance is bigger on larger displays.

Take this test for example that shows the effect:

https://www.testufo.com/mousearrow

If you run this test on a, say, 5" phone, the effect is barely visible. On a 27" display it's way more visible, since the gaps between each frame are bigger.

[MoinWoll]

Thank you for your answer and the example! I, tried it on different monitors and the size definitely makes a difference.

However, in Chief Blur Buster's article on the stroboscopic effect he mentions that motion blur counteracts the visibility of the stroboscopic effect. Couldn't turning off sharpening filters have an effect similar to adding motion blur and consequently decrease the visibility of the stroboscopic effect and vice versa? To be clear, I don't mean increasing or decreasing sharpness by varying display resolution, but by filtering or not filtering the rendered, fixed resolution image in a certain way.

[RealNC]

Sharpening filters are not removing motion blur. They increase contrast and reduce normal blur. To hide the stroboscopic effect, you need to add motion blur. A good test is a game like Doom 4 or Doom Eternal, since they have a motion blur slider. The higher you set it to, the less visible the stroboscopic effect gets.

[MoinWoll]

OK, that makes sense, thanks! Then I must have imagined the correlation. Subtle differences in motion behavior, without the possiblity of a side by side comparison, are as hard to spot as they are easy to be imagined.

[RealNC]

Well, you could say that if sharper edges are easier to see than blurry ones, and sharpening filters do produce sharper edges, then the "clone" objects of the stroboscopic effect are easier to see if their outlines are sharper. But you can say that about anything that improves visibility. Like higher contrast, or brighter colors.

[Dirty Scrubz]

Run TAA with sharpening and you shouldn't have it.