consequences of 720p output on 1080p display

[azmun]

I recently acquired Analogue's Mega Sg and still adjusting playing Mega Drive / Genesis games on a flat panel. I turned on the scanline options and immediately noticed something was off (does not seem to simulate the CRT look well). Upon reading on the reference manual, it advised choosing 720p mode as it gives "the ideal thickness" and I must say it produced a much more convincing look in comparison to the 1080p.

My question is, are there any other advantages or disadvantages to choosing 720p on a native 1080p monitor? I figured my monitor may be downscaling the video and cause additional processing and delay but don't seem to notice much difference between the two settings. Overall, I'm a bit overwhelmed with the number and types choices and settings.

[Kez]

It depends on your display, but in many cases the display lag will be the same whether or not the signal is native res. The only way to be sure is to test it - if you provide the model someone else may already know the answer.

The only other negative is artefacts from bad scaling, but scanlines normally make this immediately obvious so it sounds like you're all good on that front.

[AndehX]

well since 720p is not an integer of 1080p, it cannot be scaled perfectly, and thus, scanlines will never look right (without some kind of filter to blur them slightly)

[Bratwurst]

Most of the 32" LCD televisions available today are 720p. Try asking your friends or family if they might have one to test the system on or just buy one... Used or new they're cheap.

[orange808]

Almost every "720p" LCD panel is actually 768p. OP should probably avoid them.

Scaling scanlines from 720 lines to 768 lines won't look good.

There might be a few LCD unicorns that really are 720p, but I hear they are rarities.

[Dochartaigh]

I never understood this either, and I just got a Mega SG this past weekend. Using FM or OSSC I've always gotten scanlines to look correct at 1080p, using 5x (which does cut off what is it? 4 pixels off the top and bottom? - which is perfectly fine). Looks nice on the Mega SG as well. They're still not CRT quality, but nothing will be until they can emulate individual phosphor bloom and decay.

I DID notice that if I was using custom settings (FirebrandX) on the Mega SG, and they weren't exactly what they were supposed to be that the scanlines would be uneven. Popped back in the correct numbers and they're perfectly even top-to-bottom to my eyes. I really didn't notice any difference in scanline quality between 720p and 1080p either (and I'm always comparing these to CRT BVM's - that's the kind of scanlines I like).

[Lawfer]

Almost every "720p" LCD panel is actually 768p. OP should probably avoid them.

Indeed.

There might be a few LCD unicorns that really are 720p, but I hear they are rarities.

I have yet to be able to confirm their existence, some manufcaturer manuals may say 1280x720, but later on somewhere else it would say 1366x768.

As far as I can tell, the only way to get native 1280x720 screens, would be to get a 16:9 CRT like one of these Sony BVMs CRTs which will be to output in native 1280x720., or get a projector which is actually 1280x720.

For 720p content (PS3, PS TV), I use Extron DSC 301 HD to upscale to 1080p.

[Xyga]

The rare times this was invoked over the years, people pointed a couple real 720p references, like an antique plasma and a lcd maybe. That info's lost deep into forums.

For 720p>1080p scaling with simulated scanlines it's hit-or-miss really, a minority of displays do this very well, barely showing uneven artifacts.
Most suck at it tho...

[Bratwurst]

Almost every "720p" LCD panel is actually 768p. OP should probably avoid them.

Scaling scanlines from 720 lines to 768 lines won't look good.

There might be a few LCD unicorns that really are 720p, but I hear they are rarities.

Oh hell, I had no idea. That's hilarious when an industry standard isn't even followed.

[Fudoh]

The rare times this was invoked over the years, people pointed a couple real 720p references, like an antique plasma and a lcd maybe. That info's lost deep into forums.

The 37" Panasonic Plasma sets used a true 720-line panel (but with just 1024 pixels of horizontal resolution instead of 1280).
Extremely easy to pick up right now on your local classifieds.

@azmun

In short: there's no disadvantage to using 720p. In most cases it's indeed prefered to 1080p, if you want nice looking scanlines.

[Xyga]

The rare times this was invoked over the years, people pointed a couple real 720p references, like an antique plasma and a lcd maybe. That info's lost deep into forums.

The 37" Panasonic Plasma sets used a true 720-line panel (but with just 1024 pixels of horizontal resolution instead of 1280).
Extremely easy to pick up right now on your local classifieds.

Oh yes figured you of all people would remember.

You're right they can still be found but it's not that easy at least not around my country.

In short: there's no disadvantage to using 720p. In most cases it's indeed prefered to 1080p, if you want nice looking scanlines.

Hum. Honestly I've become more sensitive to uneven scanlines artifacts over time, and really a lot of Full-HD displays do create that problem even if a little bit, no one can witness all of them but I'd say from my experience I liked about 1/3 of them for the job (about 10 years ago I didn't notice much if at all).

Then there's the OSSC's new H+V lines crt effect, and there it's even more hit-or-miss IMHO.
(which is why I hoped marqs could introduce a 1/2 the number of v-lines in generic x5, in order to completely eliminate the randoms of 720p>1080 scaling)

[Lawfer]

The 37" Panasonic Plasma sets used a true 720-line panel (but with just 1024 pixels of horizontal resolution instead of 1280).

So part of the picture will be cut off on the left and right sides, correct?

[tongshadow]

How about a bulky ass CRT monitor
It doesnt care about native resolutions after all

[Lawfer]

How about a bulky ass CRT monitor
It doesnt care about native resolutions after all

Yeah, but they have to support 720p.

[maxtherabbit]

How about a bulky ass CRT monitor
It doesnt care about native resolutions after all

Yeah, but they have to support 720p.

and the vast majority of consumer grade HD-CRT did not, at least not without scaling it to 1080i

720p really is an odd man out, you can use a PC-CRT or brodcast monitor or a 4k TV and integer scale it - that's pretty much it

[tongshadow]

Most PC CRTs do support 720p, but letterboxed depending on the game.
HD CRTs TV are not good however, it's basically just the negatives of both CRT and LCD tech.

[strayan]

I have a Sony Bravia D3100 that will display 1280x720 on its 1366x768 panel at 1:1 on the vga input. You can also use a Crestron HD scaler to achieve the same result via the HDMI input on most 1366x768 panels.

[orange808]

I have a Sony Bravia D3100 that will display 1280x720 on its 1366x768 panel at 1:1 on the vga input. You can also use a Crestron HD scaler to achieve the same result via the HDMI input on most 1366x768 panels.

Can you provide some details on a Crestron? 4:4:4? Frame lock? How much latency? Ringing? How does it handle NES sync jitter?

[orange808]

Most PC CRTs do support 720p, but letterboxed depending on the game.
HD CRTs TV are not good however, it's basically just the negatives of both CRT and LCD tech.

Agreed.

The problem with HD CRTs is that they can't display more than 540 visible lines a frame--and they always output 1080i. Everything that isn't 1080i goes through the scaler.

The built-in video processing is ancient tech and won't look good. So, you have to use an external machine to get decent 1080i--on top of the latency the television already has.

Meh.

[maxtherabbit]

Most PC CRTs do support 720p, but letterboxed depending on the game.
HD CRTs TV are not good however, it's basically just the negatives of both CRT and LCD tech.

Agreed.

The problem with HD CRTs is that they can't display more than 540 visible lines a frame--and they always output 1080i. Everything that isn't 1080i goes through the scaler.

The built-in video processing is ancient tech and won't look good. So, you have to use an external machine to get decent 1080i--on top of the latency the television already has.

Meh.

There are HD CRTs that do NOT scale 480p, I have one

[orange808]

Most PC CRTs do support 720p, but letterboxed depending on the game.
HD CRTs TV are not good however, it's basically just the negatives of both CRT and LCD tech.

Agreed.

The problem with HD CRTs is that they can't display more than 540 visible lines a frame--and they always output 1080i. Everything that isn't 1080i goes through the scaler.

The built-in video processing is ancient tech and won't look good. So, you have to use an external machine to get decent 1080i--on top of the latency the television already has.

Meh.

There are HD CRTs that do NOT scale 480p, I have one

I stand corrected.

Didn't know any of them bothered.

[maxtherabbit]

I stand corrected.

Didn't know any of them bothered.

All the Sonys behave the way you described, but the other brands didn't follow that script. My Samsung scans out 480p and 1080i natively with no lag, there are Toshibas that do the same

[strayan]

I have a Sony Bravia D3100 that will display 1280x720 on its 1366x768 panel at 1:1 on the vga input. You can also use a Crestron HD scaler to achieve the same result via the HDMI input on most 1366x768 panels.

Can you provide some details on a Crestron? 4:4:4? Frame lock? How much latency? Ringing? How does it handle NES sync jitter?

Says 4:4:4 in the setup menu. No idea re framelock (is there some kind of test)? No idea re latency. No ringing that I can detect. No idea bout NES sync.

[azmun]

In short: there's no disadvantage to using 720p. In most cases it's indeed prefered to 1080p, if you want nice looking scanlines.

Thank you for that information. I read few reports saying that graphics may become blurred. But I guess that isn't my case here.

Seems 720p is not being upscaled internally by my monitor. The screen is not filled, stretched or distorted in any sort of way and displays the video along with pillar boxes. I shall save my setting with this mode/resolution moving forward.

[Einzelherz]

The 37" Panasonic Plasma sets used a true 720-line panel (but with just 1024 pixels of horizontal resolution instead of 1280).

So part of the picture will be cut off on the left and right sides, correct?

No. The screens use non square pixels so the horizontal axis gets crushed down a little.

[BONKERS]

Unless your display adds significant lag to scaling 720p to 1080p. There is no downside other than it has to be scaled and won't be as sharp (Depending on your panel). But for most 240p systems. Just getting a good base scale to 480p or 720p is the most important step anyway.

[strygo]

I've had success with pairing the Extron DSC 301 with any of the 720p signals that I encounter. Using it to upscale to 1080p before reaching my Vizio 4K TV produces a better image on everything I've tried. This includes the various mini consoles, as well as the Analogue devices and even modern ones like the PS3/Xbox 360.