Take for example This projector.
In the title, it advertises 1080p resolution, however, if you scroll down, you'll see in the description:
Resolution: 800*480RGB Support Resolution: 1280x 1080p The top line describes the Native resolution. Why does the native resolution differ from the supported resolution? when I input the 1280 x 1080, does the resolution turn to a true 1280 x 1080, or is it simply spoofing me? Are there any other performance quirks to turning the resolution up?
23 Answers
Why does the native resolution differ from the supported resolution?
Because there is more than just one type of resolution. You're conflating the different types of resolutions.
The input (aka "support") resolution(s) indicate what the projector/display will accept. Naive users only look for the maximum input resolution, but you should check for support of every possible resoluion that you might use.
The native resolution is the actual number of pixels that the display can generate.
When the input resolution is larger, then the input has to be downscaled.
When the input resolution is smaller, then the input has to be upscaled.
When the input resolution matches the native resolution, no scaling is performed and you get an accurate 1:1 mapping.
You actually need to know all the specs, not just one number. The native resolution may be considered more important to picture quality, but the quality of the scalers and support for the input resolution(s) that you want to use are just as salient.
4Why does the native resolution differ from the supported resolution?
There are different reasons why a company does this. Probably to reduce the costs. Answering this question is a matter of opinion and that is considered off-topic here on SuperUser.
when I input the 1280 x 1080, does the resolution turn to a true 1280 x 1080, or is it simply spoofing me?
When you use a 1080p resolution, the image will display every 2nd line and every second column. It will use the 800x480 resolution, but display content with a higher resolution. So you will see pixels 1, 3, 5, 7, 9, ... etc. but not 2, 4, 6, 8, ... etc.
For presentations, this usually is not a big problem. For movies it isn't either. For small text, its going to be a problem.
You can mirror output from a 1280x1080p display so you can work in the higher resolution while the projector puts out a reduced resolution version of what the presenter is seeing rather than having to reduce both screens to the projector's native resolution.
