History:Mark Rejhon said:EDIT 2018: There is a new article about display MPRT / persistence in milliseconds:
Blur Busters Law: The Amazing Journey To Future 1000 Hz Displays
[Edit, added to add context]
Reviewers often use "Lines of Motion Resolution", on motion test patterns based on FPD tests:
Search: "1080 lines of motion resolution" -avsforum (excludes AVSFORUM posts)
Search: "1200 lines of motion resolution" -avsforum (excludes AVSFORUM posts)
- C|Net Review of HDTV measuring motion blur by "lines of motion resolution"
- HDGuru talks about motion blur by "lines of motion resolution"
- HDTV Magazine: Panasonic Viera touting "lines of motion resolution"
And many home theater magazines sitting here, using "lines of motion resolution" in their HDTV reviews.
Lines of motion resolution is very test-pattern specific.
- depends on speed of motion
- depends on test pattern
- depends on resolution of display (1080p versus 4K)
Milliseconds of motion resolution is test-pattern independent.
- can be measured by scientific equipment
- can be measured by human eye with certain special test patterns
- resolution independent, refresh rate independent.
Google: Moving Picture Response Time
- It's resolution independent.
- It's motion speed independent. (most displays have the same MPRT at all motion speeds and motion vectors)
- It's more test pattern independent.
- It's future proof. 1080p, 4K, 8K, VR, etc.
- Improvement is unbounded. It doesn't cap out at a specific value (e.g. "1200 lines of motion resolution")
- It easily covers the faster motion speeds often seen in video game use, an increasing use case of displays.
I'm the author of the Blur Busters UFO Motion Tests.
I feel that motion resolution needs to be I feel it's better for motion resolution to be measured in milliseconds (MPRT), rather than motion resolution measured in "lines of motion resolution". MPRT, stands for Motion Picture Response Time. Most reviews quote a "lines of motion resolution".
With MPRT, you know that mathematically, 1 millisecond of motion blur equals 1 pixel of motion blur for every 1000 pixels/second motion. Very simple math. e.g. 4ms MPRT means you get 8 pixels of motion blur during 2000 pixels/sec motion. Apples to apples, even comparing 4K displays to 1080p displays. Note that MPRT is a different measurement than LCD pixel transitions (e.g. GtG transitions), the closest analog is the time it takes for a pixel to go BWB (black-white-black).
It would be good to see more Blu-Ray motion resolution tests to migrate to the MPRT standard, rather than "Lines of Motion Resolution". Or alternatively, motion equivalence ratios (1000 / MPRT). So a display with a true "250" measured motion equivalence ratio has about 4ms of MPRT. (1000 / 4) = 250. True measured motion equivalence numbers such as "250" is also the same amount of motion blur as a hypothetical "250fps on a perfect 250Hz sample-and-hold display", and may be more user-friendly than millisecond numbers.
That said, it's easy to convert motion equivalence ratios mathematically as 1000 / MPRT = motion equivalence ratio (MER). This is measured analog to the claimed numbers often quoted on displays (e.g. Samsung CMR 960, Motionflow XR 480, Panasonic 1600 scanning backlight) and the measured motion equivalence ratios would certainly fall short of these numbers, much like measured contrast ratios fall short of claimed numbers.
Quoting by MPRT or by MER is more apples to apples.
- Resolution independent
- Test pattern independent
- Can be measured by eye or measured by scientfic equipment
- Easy to extrapolate
With the transition from 1080p to 4K, it's time to migrate away from the archaic "Lines of motion resolution" standard, and go to the modern "milliseconds of motion resolution" (MPRT) or its simple inverse, "measured motion equivalence ratio" (MER)
Edit as of June 2014: Industry has started talking about persistence more often recently. "Milliseconds of persistence" is another way to describe "milliseconds of motion resolution", since it's the same number..