Input Lag – A Second Look
I just returned a few days ago from my month long adventure overseas (sorry for the extended absence) and I thought I’d get back into things with a bit about input lag. As you know, it’s a fairly important “spec”for gaming – and it is definitely going to be a standard measurement for upcoming game reviews.
Ideally, input lag is zero (like we saw in the recently reviewed Optoma GT720), but most projectors will have some measurable amount of input lag.
So how much is too much?
Well, the average reaction time for humans is around 215 ms. (I scored 178 ms [average of 10] )
Knowing this, here are my thoughts…
>50ms - Is into the noticeable range. It is unplayable for professionals, will frustrate competitive folk and may or may not be a nuisance to the casual gamer (depending on the game).
30-50ms - Is what I would consider to be a good target range – 33 ms being a good target number (~1 frame of lag). This range will still probably be less than ideal for the pros, but only a minor inconvenience for the semi-serious. For casual gamers…this is just fine!
<30ms - If you can measure below “1 frame” of input lag (33ms), I don’t think it can be thought of as much of an issue. Many LCD TVs fight to hit this mark, so if you are paranoid about input lag, this is where you want to be…
I haven’t taken nearly enough different measurements to claim an “average” amount of projector input lag, but I’ve been playing games on my Epson 6500UB long enough to take note of some things. First, I do notice more input lag when Frame Interpolation is ON vs OFF. Theoretically, this makes sense…(it should be close to two times the lag). I was curious to see how my slightly outdated Epson stacked up against the zero input lag of the Optoma GT720.
Here are the results…
Frame Interpolation - HIGH Noise Reduction – ON (50-70ms)
Frame Interpolation – NORMAL Noise Reduction – ON (40-60ms)
Frame Interpolation – LOW Noise Reduction - ON (40-50ms)
Frame Interpolation – OFF Noise Reduction - ON (30-40ms)
Frame Interpolation – OFF Noise Reduction – OFF (10-30ms)
As you can see, the 6500UB only starts putting up some respectable numbers when both Frame Interpolation and Noise Reduction are OFF. Frame Interpolation has a fairly significant impact on input lag (as expected), but so does Noise Reduction. I thought features like NR would have some impact on input lag, but I never imagined it would be even close to the impact of FI. Pretty interesting…
I also ran some tests with FI – ON and NR – OFF just to see the results and the Epson clocked around 30-50ms with those settings (photos not shown). It may be in your best interest to turn features like NR and FI off while playing fast paced games.
This is not to say that FI is not to be used while gaming…I use FI all the time in slower paced games like Oblivion. I really like how it adds a crisp/smooth feel to the game. As I’ve said…it depends on the game. It’s up to you to decide when it’s appropriate to use these features – but remember, it does increase input lag.
That’s all for now!