Two Questions for those with a 1080p 10" tablet

[Mondozei]

Hey, I am on an iPad 4. Its mostly good, but it is quite heavy, especially with a cover that I am using.

So I'm looking to upgrade. I might think about getting an iPad Air, but frankly, I need more than 16 gigabyte of RAM and Apple is overcharging for the memory as they refuse to implement SD memory card support, which is frankly outrageous(I didn't think I'd need more than 16 gigabyte when I bought my iPad 4 back in 2012, but that was quickly disproved).
There are now tablets such as Sony's Xperia Z2 Tablet and others around 10" which are both much slimmer, lighter and in Sony's case also waterproof. And it has support for SD cards.
Yet the only real thing that makes me hesitant is the resolution. It has 1200p resolution.

There are two questions I have.

1. The first one is directed at people who have that exact resolution or who are technical in general and can answer the question; namely, when you have 1200p instead of 1080p, how is scaling down to 1080p like?

I've heard some people say that if you don't have symmetrical scaling, i.e. from 720p is exactly 50% of what 1080p is, thus viewing 720p videos on an 1080p screen isn't a problem. How is it for 1200p screens watching 720p and 1080p videos?

2. The second is more about readability. This is for both those with an 1080p and 1200p tablets on 10" screens. Is it blurry? Can you make out any pixels?

Thanks!

 

[Rdmkr]

720p is exactly 50% of what 1080p is

it's 4/9, or 44.444% (speaking of 1280x720 vs. 1920x1080)

in each dimension it's 2/3 or 66.666%, which is hardly an ideal ratio for compression or stretching out.

I'm inclined to say displaying undersampled content on a "too good" screen is rarely a problem...

 

[velis]

1. Bands. You get a black border above and below the video. Besides, movies are often in 20:9 or even wider, so you would get bands in either case. Heck, you are probably getting them on your iPad as it's 4:3. It would be a funny looking video if you didn't.

2. This is really dependant on your eyesight. I can see pixels if I take a magnifying glass / stare really mean like , but not otherwise. Full HD on 10" is a "good enough" resolution IMHO, especially for watching movies / playing games. That said, Nexus 10 looks even better, but not revolutionary so.

 

[rituraj]

This tablet is 1920X1200 which is 16:10 ratio. The typical aspect ratio for your videos is 16:9. Which is exactly the ratio of 1920:1080 (fullHD or 1080p) and 1280:720 (HD or 720p) videos. This means in any of the typical videos you will have clack bars above and below.

*In older videos with 4"3 ratio, you will see black bars on the sides

Now, 720p is not 50% of 1080p

Don't think of it in terms of total number of pixels. Take the number of horizontal and vertical lines for calculations.
1080p is 1.5 times 720p in vertical direction. and 1920 is 1.5 times 1280 in horizontal direction.

Now if your video is 720p, and the screen is 1080p, then it will upscale in the following manner:
For each alternate pixel in the vertical direction, the screen will add another pixel of its own which was not originally there in the video. i.e. it will display pixel 'A' fine as it is, but then it will show the next pixel 'B' twice, let's call it B*. Then it will again show pixel 'C' then pixel 'D' twice as 'D' and 'D*'. Thus for every two pixels it is showing you three, one of which is not real but is a replica of the previous. While this seems like this will cause undesireedd artifacts in your video, in a screen this small where each pixel is 0.0046 inch size (0.116milimetre, or almost one tenth) you will need a magnifying glass to see them.

The same thing happens in the horizontal direction to convert 1280 pixels into 1920 pixels.

Now, for your question, if the screen is 1920X1200, that means it can upscale the 720p video (which has 1280 pixels in the horizontal direction) by 1.5times in the horizontal direction, but that is not possible in the vertical direction since 1.5 times will only be 1080 pixels. Which means you will have black bars above and below which will occupy the rest of the horizontal lines (1200-1080 = 120 pixels will be wasted)

But if you have been told that 720p looks fine on 1080p screen, that means those people could not see that added duplicate pixel and in this tablet it will appear the same, but yes the black strips will be there above and below.

The exact double scaling of a 720p video will be on a 2560X1440 sceen and the same for a 1080p video will b a 3840X2160 (aka 4K) screen, where each vertical and horizontalline will be replicated, i.e. one pixel worth of content will be shown by 2X2= 4 pixels.

I don't know if some dynamic interpolation is done in this process or not, but this is my limited understanding.

About you second question regarding readability I think I already answered that. It has a pixel density of about 225 which is pretty darn good (each pixel measuring .004 inch). If you need personal opinion my galaxy note II has a 265 ppi and I have to really look (not "see") to detect them. Since you are going to hold it at a considerable distance, I dont think it will be a problem at all. (Personally I prefer them to be visible if the need arises, such as to find out if there is a dead pixel or two, which is again very unlikely in today's standard)

Hope this was helpful..

 

[Mondozei]

This tablet is 1920X1200 which is 16:10 ratio. The typical aspect ratio for your videos is 16:9. Which is exactly the ratio of 1920:1080 (fullHD or 1080p) and 1280:720 (HD or 720p) videos. This means in any of the typical videos you will have clack bars above and below.

*In older videos with 4"3 ratio, you will see black bars on the sides

Now, 720p is not 50% of 1080p

Don't think of it in terms of total number of pixels. Take the number of horizontal and vertical lines for calculations.
1080p is 1.5 times 720p in vertical direction. and 1920 is 1.5 times 1280 in horizontal direction.

Now if your video is 720p, and the screen is 1080p, then it will upscale in the following manner:
For each alternate pixel in the vertical direction, the screen will add another pixel of its own which was not originally there in the video. i.e. it will display pixel 'A' fine as it is, but then it will show the next pixel 'B' twice, let's call it B*. Then it will again show pixel 'C' then pixel 'D' twice as 'D' and 'D*'. Thus for every two pixels it is showing you three, one of which is not real but is a replica of the previous. While this seems like this will cause undesireedd artifacts in your video, in a screen this small where each pixel is 0.0046 inch size (0.116milimetre, or almost one tenth) you will need a magnifying glass to see them.

The same thing happens in the horizontal direction to convert 1280 pixels into 1920 pixels.

Now, for your question, if the screen is 1920X1200, that means it can upscale the 720p video (which has 1280 pixels in the horizontal direction) by 1.5times in the horizontal direction, but that is not possible in the vertical direction since 1.5 times will only be 1080 pixels. Which means you will have black bars above and below which will occupy the rest of the horizontal lines (1200-1080 = 120 pixels will be wasted)

But if you have been told that 720p looks fine on 1080p screen, that means those people could not see that added duplicate pixel and in this tablet it will appear the same, but yes the black strips will be there above and below.

The exact double scaling of a 720p video will be on a 2560X1440 sceen and the same for a 1080p video will b a 3840X2160 (aka 4K) screen, where each vertical and horizontalline will be replicated, i.e. one pixel worth of content will be shown by 2X2= 4 pixels.

I don't know if some dynamic interpolation is done in this process or not, but this is my limited understanding.

About you second question regarding readability I think I already answered that. It has a pixel density of about 225 which is pretty darn good (each pixel measuring .004 inch). If you need personal opinion my galaxy note II has a 265 ppi and I have to really look (not "see") to detect them. Since you are going to hold it at a considerable distance, I dont think it will be a problem at all. (Personally I prefer them to be visible if the need arises, such as to find out if there is a dead pixel or two, which is again very unlikely in today's standard)

Hope this was helpful..

That was an amazing amount of effort you put in to your answer, thanks!

(And thanks to everyone else, too!).

Yeah I'm pretty convinced that the PPI won't be a major issue.
That being said, I am using an iPad 4 right now, as I said earlier, and it's never fun when you regress(even if only slightly) on any issue, whether it is the power of the SoC, the resolution, the weight and so on.

Nevertheless, the Xperia Z2 Tablet looks pretty awesome. And I love the SD card <3

 

[rituraj]

That was an amazing amount of effort you put in to your answer, thanks!

(And thanks to everyone else, too!).

<3

Actually I was curious too and read about it somewhere and wanted to share with somebody. So you were the first victim..