Which I found interesting enough to hook up a phototransistor to my OSSC and test it myself. And yes, assuming the OSSC measures lag correctly he is rightXyga wrote: Remember in their test they still give you middle-screen measurements which is not 'input lag period' but input lag+1/2frame@60, so sustract 8.3ms
For instance say you want a TV for displaying a device or two that you know will produce/cost 2 frames, but don't want your input lag chain over 2.5f (42ms); if you pick a model in their list they measured under 16ms @1080p, you're safe.
Even though we're at the end of 2018, a lot of 2017 models are still relatively easy to find, and considering the many sizes, all combined with 2018's thats quite a large choice.
Apply this to a less laggy chain and the number of eligibe models increases significantly, even up to the LG OLEDs that are just under 1 frame.
However, I did run into some weird issues measuring the lag in 1080p and 1200x1080 on my C7 last night, that I just can't make much sense of. Hence the reason for this topic.
I'll try and describe in detail how I did my measures, so someone can correct me if I did anything wrong at any point. But here they are for regular game mode, ISF and with PC mode:
I measured the bottom right corner of the screen, as my cable wasn't long enough to reach the middle or the upper left, I couldn't find anywhere that said that all three areas needed to be measured, so hopefully this is not the cause of these issues
The first thing I did was to measure 480p using no input source on the OSSC. I took several measures and rounded up the number a bit to 12ms which seems to match what Xyga said in the other thread as HDTVtest claims about 21ms lag with the Leo Bodnar tester.
From here on I used a Super Nintendo as input, just so I could run through the various 3x (720p), 4x (960p) and 5x (1080p, 1200p) modes. I chose the SNES as it's known for being one of the most troublesome consoles to use with the OSSC, but I ran the same tests with a PS1 as well with no difference in the measured lag.
What's weird is that I initially got 12ms lag across all resolutions, which is what I expected, but after measuring the lag of the 1080p mode a few times, the lag rose from 12ms to 28ms. I switched back and forth between modes on the TV and resolutions on the OSSC, but the lag remained at 28ms. Which doesn't make any sense as all reviews I've read of the LG C7 claimed "21ms" in 1080p mode.
I then decided to run the OSSC directly to my TV, as surely this would be caused by my Yamaha RX-A1080 receiver, which I had always assumed to be completely lag free.
And the first few 1080p tests did say 12ms again, until it for no reason jumped up to 28ms just like it did with the AVR in the chain. I then tested the entire range of resolutions and there was no difference with or without the AVR. Meaning that the Yamaha is indeed lag free as I had always assumed.
But why do I get these weird measurements in 1080p and 1920x1200? I'm pretty sure that 28ms is wrong and that 12ms is correct. The measurement boxes in these resolutions are larger than in any of the others, so is there a bug in the OSSC? I tried zooming the image on the TV, to make the boxes similar in size to the other resolutions, but that made no difference.
Also, I found that disabling Real Cinema in regular ISF mode lowered the lag by quite a bit but I didn't test every resolution. 480i was measured using a GameCube with the OSSC set to pass through the resolution, so I could test the TVs deinterlacing speed.
This is the information I used to make the lag tester: http://junkerhq.net/xrgb/index.php?titl ... ncy_tester
I swapped R43 with a 150K resistor, and I used a matchbox too, to block out any light to the transistor.