Samsung Series 9 S27A950D "Frame Sequencing"

[ericl]

I really like my Samsung S27A950D for a lot of things. It was one of the first 27" 120hz LCDs, it has a nice design but in terms of performance it doesn't hold up well when using the frame sequencing (apparently the equivalent of lightboost for the samsung screen)

It actually hurts the eyes to use it and I'm not sure why.

In comparision, using Lightboost on a BenQ 24 144hz" is beautiful, fast and responsive. It doesn't hurt my eyes at all in spite of reducing the brightness.

This makes me completely unable to use lightboost/frame sequencing on the 27" Samsung which is a real shame. If someone knows why (perhaps the Samsung is too slow?) or was considering purchasing the Samsung monitor, this is for them!

[Chief Blur Buster]

I really like my Samsung S27A950D for a lot of things. It was one of the first 27" 120hz LCDs, it has a nice design but in terms of performance it doesn't hold up well when using the frame sequencing (apparently the equivalent of lightboost for the samsung screen)

Yep, I can see you followed the Samsung Zero Motion Blur HOWTO.

It actually hurts the eyes to use it and I'm not sure why.
In comparision, using Lightboost on a BenQ 24 144hz" is beautiful, fast and responsive. It doesn't hurt my eyes at all in spite of reducing the brightness.

This is mysterious, as the strobe frequency is the same, so that is quite strange.
However, strobing can get someone to the "edge" of eyestrain, where other monitor deficiencies can "tip you over" to the eyestrain issue.

So I shall cover other known eyestrain causes, and attempt a process of elimination.

Here's some possible causes:
-- Color spectrum differences in their strobe mode. BENQ does use lower blue light spectrum, I believe.
-- Field of view. The Samsung screen is larger, so covers your vision, so has more opportunity to push you over the threshold.
-- Brightness differences. Extreme brightness or extreme dimness can bother your eyes.
-- Motion quality differences. Make sure you enable "Response Time" -> "Normal" before you go into 3D mode.

Enabling a monitor's strobe does entail slightly increasing the risk of eyetrain, but can be compensated by other factors (reduced motion blur eyestrain, elimination of excessively bright picture). This explains the mixed eyestrain reports with strobe backlights (some get more eyestrain, some get less eyestrain). What might be happening is that your BENQ 24" had less eyestrain-inducing factors than your Samsung 27" does.

If you forgot to change "Response Time"->"Normal", exit 3D mode, change that setting, then go back. Using a Response mode other than "Normal" creates motion artifacts, especially when viewing http://www.testufo.com/ghosting or http://www.testufo.com/photo on the Samsung. If this was the case, what you may be witnessing is a motion-artifact eyestrain, which is an underreported eyestrain cause.

As a test:
(1) Verify the Response Time setting.
(2) Try pushing your Samsung 27" about 10% further back relative to what you normally use for a 24" inch monitor.
(3) Adjust the brightness of the Samsung, to match the LightBoost monitor.
(4) Keep the proportional viewing distance similiar (24" view distance from 24" monitor, 27" view distance from 27" monitor).
(5) Adjust the ambient lighting in your room to match the same environment that you use your LightBoost monitor, including any illumination of the wall behind the monitor (if necessary). For best eyestrain reductions, make sure your monitor is not obnoxiously the brightest thing in your field of vision.

Also, Samsung is known to have much more input lag (>20ms) in strobe mode, than LightBoost monitors. Although I don't think lag is an eyestrain factor, it's another 'discomfort'-related factor to keep in mind.

[ericl]

Wow that was quite a detailed explanation. (And yes, I definitely did follow your guide!)

I believe it most likely due to additional input lag (20ms is huge, no?) because I did set it to "normal" and do have the viewing distance at a close-to-equivalent-distance to the 24" monitor.

If we combine a slower response time in "normal" mode, with huge input lag, combine that with the larger 27" size and glossy finish... that's probably the reason why it's unbearable (at least for me) to use.

The BenQ is quite amazing though... I'd really like to get the next "ultimate" monitor in 24" for gaming. I wonder what that will be!

[Chief Blur Buster]

If we combine a slower response time in "normal" mode, with huge input lag, combine that with the larger 27" size and glossy finish... that's probably the reason why it's unbearable (at least for me) to use.

The eye-hand coordination disconnect does create motion sickness for some, which can manifest itself as headaches. This might, indeed, be what you are witnessing. If this is the case, you will definitely want to stick to TN-based strobe backlight monitors for the forseeable future, if you want the lowest latency strobing available.

The BenQ is quite amazing though... I'd really like to get the next "ultimate" monitor in 24" for gaming. I wonder what that will be!

For me, the ultimate solo gaming monitor is the EIZO FG2421, but it has 18ms of input lag -- which may be an issue for fast-fwitch FPS gameplay (e.g. Quake) for some people, including you.