Re: DLP BFI for Consoles
Posted: 13 Jan 2022, 02:38
Chief, is it normal for total hardware latency to be higher at 60Hz than 120? I've been using a 330fps camera to compare input lag between a couple of DLP projectors and my XL27, and get these averaged results at 60Hz (midscreen measurements as best I can):
XL2720Z: 66ms
W1210ST: 72ms
HD29HST: 72ms
I've seen the monitor's midscreen lag reported at around 15, and the PJs are both advertised at 16.7, so this data checks out. But then at 120Hz I get these averages:
XL27: 36ms
W1210: 65ms
W1210 3D: 65ms
HD29: 43ms
HD29 3D: 61ms
The HD29 is advertised at 8.4, and since I don't believe the XL is 7 faster than that, I must be running into the limitations of my camera here (a fraction over 3ms between frames). But why the discrepancies between 60Hz and 120? I used a laptop with a 1000Hz polling rate for the mouse, kept it offline, and had as little running as possible. I set an LED for 45ms when I leftclicked (so it was lit for 15 of those 3ms frames).
If the HD29 is 8ms, engaging its 3D mode suggests around 25, and a touch higher than that for 3D on the W1210. But as you can see, the HD29 can't be 8ms of 43 and 16.7 of 72, nor can the XL27 be 30ms apart. Not unless the GPU (Vega 8) is also slower at 60Hz or something like that. Any ideas? I used Kulagin's test - http://plnkr.co/edit/Q8CzgCo451XKKFbdmJAH
Might you or someone else here be able to sell me a lag tester? I'd love to get accurate figures for the 3D mode on this Optoma, because I'd be quite happy with 25ms if I were able to confirm. The Leo Bodnar and Time Sleuth are limited to 60Hz and I can't find a 120 option for sale. The resolutions I've tested at 120Hz are 1280x800, 1440x900 and 1080p, so I don't need the bandwidth for 4K.
Thanks for all the info above by the way - I've been busy and forgot to check back. I did buy and return a Sony A80J because I was disappointed by its 60Hz BFI. It only has one option for 60, and your alien's three eyes were only clear at 240 pixels per second. At 480 its eyes turned into four Xs. I believe this is 8ms persistence? Its flickering isn't worth it for that level of blur reduction IMO.
This Optoma has both DLP Link and 3D Sync by the way, and I believe the latter works independently? On my camera footage I see black frames with the former mode but not the latter, which appears to have some kind of dithering applied? The colours from the BenQ's RGBRGB wheel are deeper.
If there were a BFI box I'd definitely pay a few hundred for one! Then I could run this PJ in its 8ms mode with full control over how much BFI latency I was adding. Turns out my single-strobe duty on the XL is 1:0:0:0, but I wouldn't need more than 1:0 from the PJ at 60Hz. The cool thing with PJs is that I don't notice any flicker, so it'd be amazing to play 60fps games with imperceptible BFI!
Yeah, I'd absolutely pay good money for an HDMI box that routed the incoming video to apply low-latency BFI to an output cable.
XL2720Z: 66ms
W1210ST: 72ms
HD29HST: 72ms
I've seen the monitor's midscreen lag reported at around 15, and the PJs are both advertised at 16.7, so this data checks out. But then at 120Hz I get these averages:
XL27: 36ms
W1210: 65ms
W1210 3D: 65ms
HD29: 43ms
HD29 3D: 61ms
The HD29 is advertised at 8.4, and since I don't believe the XL is 7 faster than that, I must be running into the limitations of my camera here (a fraction over 3ms between frames). But why the discrepancies between 60Hz and 120? I used a laptop with a 1000Hz polling rate for the mouse, kept it offline, and had as little running as possible. I set an LED for 45ms when I leftclicked (so it was lit for 15 of those 3ms frames).
If the HD29 is 8ms, engaging its 3D mode suggests around 25, and a touch higher than that for 3D on the W1210. But as you can see, the HD29 can't be 8ms of 43 and 16.7 of 72, nor can the XL27 be 30ms apart. Not unless the GPU (Vega 8) is also slower at 60Hz or something like that. Any ideas? I used Kulagin's test - http://plnkr.co/edit/Q8CzgCo451XKKFbdmJAH
Might you or someone else here be able to sell me a lag tester? I'd love to get accurate figures for the 3D mode on this Optoma, because I'd be quite happy with 25ms if I were able to confirm. The Leo Bodnar and Time Sleuth are limited to 60Hz and I can't find a 120 option for sale. The resolutions I've tested at 120Hz are 1280x800, 1440x900 and 1080p, so I don't need the bandwidth for 4K.
Thanks for all the info above by the way - I've been busy and forgot to check back. I did buy and return a Sony A80J because I was disappointed by its 60Hz BFI. It only has one option for 60, and your alien's three eyes were only clear at 240 pixels per second. At 480 its eyes turned into four Xs. I believe this is 8ms persistence? Its flickering isn't worth it for that level of blur reduction IMO.
This Optoma has both DLP Link and 3D Sync by the way, and I believe the latter works independently? On my camera footage I see black frames with the former mode but not the latter, which appears to have some kind of dithering applied? The colours from the BenQ's RGBRGB wheel are deeper.
If there were a BFI box I'd definitely pay a few hundred for one! Then I could run this PJ in its 8ms mode with full control over how much BFI latency I was adding. Turns out my single-strobe duty on the XL is 1:0:0:0, but I wouldn't need more than 1:0 from the PJ at 60Hz. The cool thing with PJs is that I don't notice any flicker, so it'd be amazing to play 60fps games with imperceptible BFI!
Yeah, I'd absolutely pay good money for an HDMI box that routed the incoming video to apply low-latency BFI to an output cable.