Picture Resolution Confusion!

[Munzy]

Guys, got a question that’s probably dumb...

I have a 720p max resolution laptop attached to a 1080p projector in our cinema. The laptop runs Kodi and I have a SSD with all my movies on.

I’ve never given it much thought but it suddenly occurred to me today that if I play a 1080p movie on the laptop with its max resolution of 720p and that display is then mirrored to the 1080p projector what quality am I actually seeing?

My guess is 720p upscaled so not a true 1080p image.

Anyone understand this enough to tell me because I’m not sure?!

 

[Nozzle]

The resolution capability of the actual LCD panel, and the capability of the chipset that drives it aren't the same. The LCD panel is fixed, the chipset will be capable of various settings (just not when displayed to the LCD)... this means when driving a different output, i.e. a plugged in monitor or projector you might be able to select a different screen res that's 1080i or 1080p compliant.

All that said, I'd be surprised if your actual res is only 1280*720 as that's quite small for a modern PC, so when you state "I have a 720p max" perhaps this is more an expression of the standard of HD movie is is actually capable of decoding.

Right-click in a blank space of the desktop, go to display settings, and post a screen shot of your options. Both with and without the projector plugged in.

Nozzle

 

[SFK]

Yes, on my computer when I mirror the laptop screen to external source (so both are on showing same image) the output is the same resolution and aspect ratio shape (so can get weird effects) as the screen as video processor cannot cope.

So to best match the device I am sending to I always put it on two screen mode for presentations and output only (screen off) for videos to projector.

But is your projector a true 1080 projector with actual 1080 pixels.

Sfk

 

[Munzy]

Ah interesting, thanks!

it’s an old laptop so 720p is the max selectable screen resolution I see in the Screen Resolution settings. That said, I haven’t tried outputting the image to the projector only (laptop screen off) which might then give me a 1080p option being as my projector is true 1080p.

I’ll take a look and report back.

 

[Nozzle]

But is your projector a true 1080 projector with actual 1080 pixels.

^^^Good point, the actual res of the projector might well be much less that 1080. Much less

Nozzle

 

[Munzy]

Got to the bottom of it.

Switching the laptop output to the projector only opened up the ability to increase resolution to 1080i which was an improvement on the 720p I was seeing when both laptop screen and projector were on.

Because I knew the projector was 1080p capable and my film library is pretty much all 1080p I decided to upgrade the laptop to a newer version to get a proper 1080p output and not the interlaced version.

All good now!