CurtPalme.com Home Theater Forum

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

What, in your opinion, is the lowest tolerable (progressive) scan rate on a Marquee?

At what point does flicker become objectionable to you?

The reason I'm asking is to try to figure out the minimum bandwidth required for higher than 1080P resolutions.

gjaky · Joined: 05 Jun 2010 Posts: 2802 Location: Budapest, Hungary

Go interlaced, there was a thread about this by noos@xp37+

barclay66 · Posted: Mon Feb 15, 2016 8:14 am Post subject:

Hi,

As I see it, the sensitivity to flicker is different from person to person.
Maybe You should collect opinions from several people using a standardized scheme.
So You would be able to create some statistics. Here's an example using my tolerance levels:

Resolution - Flicker
>70p - Invisible
70p - Invisible
60p - Noticeable
50p - Tolerable
48p - Tolerable
30p - Annoying
<30p - Annoying

Key:
Invisible - No flicker percepted, perfect
Noticeable - Some flicker in peripheral areas, still good
Tolerable - Flicker visible when focusing on it, still OK
Annoying - Predominance of flicker makes it unwatchable

Regards,
barclay66

tschaeikaei · Joined: 08 Apr 2013 Posts: 490 Location: Germany/Saarland

Good morning,
interesting you notice flicker at 60Hz. I think you talk about your Marquee using a P22 HKA green.
I always thought my fast P43 green makes me see flicker at 60Hz and i don't notice anything at 72Hz. Never tried 70Hz.
I think many people run their projectors at 60Hz. So do you think you are very sensitive to flicker?
By the way i never noticed flicker on my 9PG on 60Hz, but i did not watch out for it.

If i would try 4k interlaced today, i would maybe start with 48Hz. Barclay and i would surely not like it, but may be that you are less sensitive.
But even if you have to go up all the way to 96i (to avoid motion blur), you'd still end up with a
bandwidth equal to 48p.
So, yes i think interlaced is the way to go. There is a thread where two people fought each other with some numbers about 4k bandwidth (and pixel clock Smile

).

Changed U17 and U20, now beeing about to try if the board does it again. Would have been more elegant to measure voltages and waveforms
while running, but no chance to reach the location. I knew troubleshooting would be a pain in the ass when the pj is on the ceiling.

Regards, Julian

barclay66 · Posted: Mon Feb 15, 2016 2:00 pm Post subject:

gjaky · Joined: 05 Jun 2010 Posts: 2802 Location: Budapest, Hungary

Personally I find 60Hz very annoying, and still can see the flicker of 72Hz, but watchable, I use 1080i 96Hz, and that I find perfect flicker wise.
I found Marc's old 4K thread, kudos to the Sony HDIH-2000 Razz

https://www.curtpalme.com/forum_archived/viewtopic.php@t=34138.html

cmjohnson · Joined: 03 Apr 2006 Posts: 5180 Location: Buried under G90s

For the moment I'm going to set 48 Hz as the absolute minimum requirement, in the long-shot hopes that there might be some way to get 4K running on my Marquee after suitable mods. (Which include a phenomenally rare set of special tubes made for the HR project, which are designed to be sharper than LUGs but have a slower phosphor like LCPs, apparently.)

Even if I don't get FULL 4K, then I am at least hoping for downsampled 4K giving me something between 4K and 2K. Maybe 3, or 3.5K might at least be possible.

The tough part will be finding a way to get the HDMI 2.0 signal to cough up an RGB signal. Without that, this egg will never hatch.

Spanky Ham · Joined: 22 Mar 2006 Posts: 5643 Location: Comedy Central

Good idea barclay about standard.

Chris Stephens recommends using the lowest refresh rate you can tolerate for the best image.