overscan in 2020
May 19, 2020 9:06 AM   Subscribe

If I buy a tv manufactured in 2019 or 2020, will I be able to see every pixel it advertises?

My current TV is a Sony SXRD kds-55a3000 (LCD projection)
Since almost day 1 I have been disappointed that it does not appear to actually have 1920x1080 pixels. If I leave it at 0 scaling, then a test target looks correct, but I lose a few pixels around the edge. If I change the scaling, then I can see the whole target, but get the expected aliasing issues. I understand people call this overscan, but that doesn't really make sense to me on a physical panel that has a feature for every pixel. Either your panel has the right number of pixels or it doesn't. Maybe for my tv, this is due to a mechanical alignment between the projector lens and screen. But since I can't adjust this, the difference doesn't really matter.

My question is, does this still happen on modern tvs? Are manufacturers selling HD or 4k TVs that still crop the image? Are there specs or terms I should be looking for if I want to be able to view my full computer output without scaling? At the time I got the SXRD, there was talk about needing a tv that actually described itself as a 'monitor,' but I don't know if I ever saw those.

I am currently eying an upgrade that advertises a 4k resolution of 3840x2160. Can I trust that this means I will be able to see every pixel and not that it just accepts a video frame that large?
posted by stobor to Technology (7 answers total)
 
Best answer: Are you planning on buying another rear-projection TV? (Do they even make them anymore?) Most (all?) flat-panel displays have the pixels embedded in the actual surface that displays the picture, with either a backlight (LCD displays) or the pixel element itself (OLED displays) generating the light, and you should see the entirety of the picture for supported resolutions.
posted by Aleyn at 2:31 PM on May 19, 2020 [1 favorite]


You may also find this article about using TVs as PC monitors helpful.
posted by Aleyn at 2:36 PM on May 19, 2020


Response by poster: No, I'm done with projection, looking at OLED this time around.

I got that SXRD in '07 or 08, so that was definitely a different age. I just felt misled and don't want the same frustration this time. It would be very easy for panel manufacturers to save costs/improve yields by trimming edges and I would not be surprised if they were still using "HD" and resolutions as marketing terms and not specs.

I don't use a PC very often, but even the new appleTV doesn't offer to resize the screen, so progress bars, captions, station logos, etc are often clipped. And if I did have to use a STB or the onscreen menu to resize the image, then why would I spend $$$ on picture quality?
posted by stobor at 3:19 PM on May 19, 2020


Best answer: I've seen some cheap "HD" sets that use lower resolution panels (e.g. 1360x768) while still pretending they're 1080. Overscan basically died with mechanical image projection though.
posted by neckro23 at 3:21 PM on May 19, 2020


You'll want to check the resolution in the specifications for the set you're considering for the exact resolution the TV supports, though if they advertise it as 4K or Ultra HD (UHD) it should be at minimum 3840x2160 resolution, and Full HD (or FHD) is 1920x1080 at minimum. (Though as neckro23 mentioned, an "HD" panel that isn't specifically Full HD can be a lower resolution.) You'll get all of the pixels of the specified resolution, you won't get clipping and you won't have to resize the picture to see anything.

I have not heard of any manufacturer trying to shave off some resolution on these panels; the economies of scale for flat panel manufacturing processes works better the more of the same size and resolution panels they produce, and any such deception is very hard to hide and easy to verify so there's not much incentive to play games with the resolutions or "viewable area" these days.
posted by Aleyn at 12:01 AM on May 20, 2020


Best answer: I think all modern displays have a 1:1 pixel mapping mode when fed digital video at native pixel count. Analogue video might be a different story, there might be geometry issues there still.

Bottom line is, overscan and pixel count are unrelated, you got overscan because you had a projection display.
posted by Bangaioh at 3:07 AM on May 20, 2020 [1 favorite]


The 1:1 mode is often, maybe always, called “Just Scan” in the menus. I can’t offhand think of any display I’ve used that was digital, non projection, and didn’t have a “Just Scan” mode that defeated overscan.

If you get an OLED, note that true 1:1 requires turning off the screen shifting, which is part of the protection against burnin.
posted by doomsey at 4:38 PM on May 20, 2020


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