User blog comment:Scooter8pie/As Far As the Eye Can See/@comment-4583259-20111129133142

I'm pretty sure you can see the bottom from the top, without any restrictions apart from what you have already noticed with horizontal distances. In other words, if you can see any of the blocks in a chunk, then you can see every block in the chunk (chunks are 16x16x128 blocks in size, with the 128 in the vertical direction, or maybe it's 127 instead of 128.) And you can get to a vantage point higher than 65 off the ground using the jetpack. (That's how I took this photo: File:Geology-excav-v3.jpg) So your visibility distance in the vertical direction would be about 157 (127 plus 30 for the v3 jetpack).

You should try hitting the (i) button (options) and then hit OK without changing anything. I notice when I do this, some extra chunks get rendered for a while. Immediately after I hit OK, I get 7 chunks in any direction plus my own chunk:



I had to take that photo really quickly, because after less than a second, it drops down to something more like this:



and if I wait maybe 20 seconds, it eventually settles down to my own chunk plus 3 in the 4 main directions:

.

However, these variations only happen on my iPad. On my iPhone 4, hitting (i) and then hitting OK never seems to have any effect.

In these photos I used the electronic number code: 1=brown, 2=red, 3=orange, 4=yellow, 5=green, 6=blue and 7=purple. I am standing on number 0. See my blog on signs. 7 chunks is 112 blocks.

So if I built a tall tower and used the jetpack, and hit (i) and OK and took a photo really really quickly, I guess I could see (square root of (157^2+112^2)), which works out to 196 blocks or 496 meters.

And yes, that's a huge disk in the distance. It's a marker for the place I throw my Disks.