how many pixels per inch can the human eye see?

• 04-19-14, 02:19 PM
windhchaser
how many pixels per inch can the human eye see?
growing up some of us had a vcr on a 27 inch tv that's around 15 pixels per inch. now we have android tablets that have around 300 ppi. my question is can the human eye even see that many?
• 04-19-14, 03:20 PM
black_box
depends on how close you are to the screen, but yes, we're close to the limit.
• 04-19-14, 03:22 PM
windhchaser
handheld distance ..
• 04-19-14, 04:29 PM
skijor
Quote:

Originally Posted by windhchaser
handheld distance ..

If you're an orangutan, that's not so close. Just sayin' :p
http://www.imfdb.org/images/4/42/EveryW004.jpg
• 04-19-14, 04:48 PM
windhchaser
Quote:

Originally Posted by skijor
If you're an orangutan, that's not so close. Just sayin' :p
http://www.imfdb.org/images/4/42/EveryW004.jpg

good movie
• 04-19-14, 05:19 PM
Artkansas
Your NTSC VCR had a horizontal resolution of 720 pixels. Divided by 27", that works out to about 27 pixels per inch.

Well, according to wikipedia, your minimum angular resolution is "approximately 0.07°". The rest depends on how close the pixels are and how big they are.
• 04-19-14, 07:57 PM
Wilbur Bud
CarltonBale.com » 1080p Does Matter ? Here?s When (Screen Size vs. Viewing Distance vs. Resolution)

While I disagree that 1080p matters, the chart on the page referenced that shows what you can see at which distance versus various resolutions is a good reference
• 04-19-14, 08:41 PM
Jseis
Eagles are a great comparison to humans because the physical size of their eyes are similar but an eagle can discern objects well over twice what we can. Here's a good link. Supposedly an eagle can spot a rabbit at 2 miles. Probably depends on the background but I might be able to spot a basketball/exercise ball? against a light field at one mile in my younger days though a mile is long long away. There was a great eye test that Egyptian military men gave recruits. They would have them look at the the Big Dipper and ask which star was actually two stars. I could see that difference at age 25-26 but today at 59...unlikely (though I bet my Dad could at 90...he could still read fine print without classes and had excellent long range vision).

Journey North Bald Eagles
• 04-19-14, 09:05 PM
bjtesch
Quote:

Originally Posted by windhchaser
my question is can the human eye even see that many?

I think the point is that you make them small enough so you can't see the individual pixels. Plus it does depend on the viewing distance. I have an iphone 4 and I'm not sure that I can see the pixels on its screen, so I would say that they have reached the practical limit. I have an ipad 2 and I can see the pixels on its screen. The screen is completely satisfactory to me because it is much larger than the iphone screen. I don't feel the need for the retina display that is in the new ipads.

My wife's new Lenovo ultrabook has a very high resolution screen. Start it and go to desktop and the icons are very small. Start the average Windows app and the text is very small. Some apps can scale up well enough but others don't. I just changed the resolution through Windows to run the screen at a lower resolution.
• 04-19-14, 10:05 PM
rm -rf
Old 300 dpi laser printer's fonts don't look nearly as good as the 600 to 1200 dpi modern ones.
• 04-26-14, 07:18 AM
Garfield Cat
Its about what you're looking at. Its not really the pixels but the image that the pixels are creating, the visual effect. A still picture and a moving image are going to be captured by the eye and brain differently.

Most interesting is watching sporting events in high definition. The overall experience is noticeably different than non high definition.