| Page 2 of 2 | 1 | 2 |
|
|
|
optimum viewing distance vs screen size - SD & HD
Richard Russell wrote:
I can't help with respect to the earlier treatise, but it is generally reckoned that the visual acuity of the eye is approximately one minute-of-arc. That implies a viewing distance of 6H (six times the picture height) for SD, 4.8H for 720p HD and 3.2H for 1080p HD. For HDTV critical viewing the ITU recommends 3H; I believe the BBC tends to use 4H. Fred: Richard has nailed it. This is how you work out the optimum viewing distance. HOWEVER, you should bear in mind two things. 1/ If your eyesight isn't perfect you won't be able to resolve to 1 arc-minute, so you'd need a bigger screen for a given viewing distance. 2/ A very important factor is how big you like the picture. I have a 55" TV which is just the right size for my viewing distance, but many people find it too large for comfort. -- SteveT |
optimum viewing distance vs screen size - SD & HD
Brian Gaff wrote:
So, if there are artifacts, why bother with hd? I have no duch issues these days, I get rid of the screen altogether! Brian A classic case of making a virtue out of a necessity. Bill |
optimum viewing distance vs screen size - SD & HD
On 30/04/2012 08:38, Brian Gaff wrote:
So, if there are artifacts, why bother with hd? Because as it's HD they give it a bigger bit budget. Which means there are fewer, smaller, artefacts. Andy |
optimum viewing distance vs screen size - SD & HD
Andy Champ wrote:
Because as it's HD they give it a bigger bit budget. Which means there are fewer, smaller, artefacts. I agree. The compression artefacts seem far less apparent on HD than on SD. At least to my eyes. -- SteveT |
optimum viewing distance vs screen size - SD & HD
On 4/29/12 4:41 PM, Richard Russell wrote:
On Sun, 29 Apr 2012 14:22:19 +0100, Fred wrote: A contributor to one of these groups wrote an excellent treatise on this subject - maybe 6 months ago. I can't help with respect to the earlier treatise, but it is generally reckoned that the visual acuity of the eye is approximately one minute-of-arc. That implies a viewing distance of 6H (six times the picture height) for SD, 4.8H for 720p HD and 3.2H for 1080p HD. For HDTV critical viewing the ITU recommends 3H; I believe the BBC tends to use 4H. So if your screen size is 42" diagonal (20.6" high) 3H corresponds to about 5 feet (1.6 metres). Of course at this distance you will see every defect, so if you want to be spared MPEG compression artefacts and the like you may be wise to increase the distance somewhat! And at a 'somewhat increased ' distance you will still see a remarkable difference between HD and SD. At least I do. gr, hwh |
optimum viewing distance vs screen size - SD & HD
"Fred" wrote in message ... A contributor to one of these groups wrote an excellent treatise on this subject - maybe 6 months ago. I can't seem to locate it, please help. My own 32" HD TV looks fantastic in HD at ~ 1-2m; but at ~ 4-5m I can't really tell much difference between HD and a "high quality" (eg BBC news, studio) SD transmission. Wish I'd bought a 40" ! TIA Google up optimum screen size. IIRC Richer Sounds had something on this. http://en.wikipedia.org/wiki/Optimum...ewing_distance but remember Yank sets are 720p. From 3m-4m probably 37"-42", from 4m-5m 47" and so on. Viewed from about 3.5m my 42" in HD looks very good and you can easily see the difference, however a larger screen might have been better because I can't make out text when I plug in the net-book unless I get closer. OTOH too large a screen and your eye can't encompass it all. From the dining area (~7m) you can't tell the difference between SD and HD. My desk PC has two 21" CRT screens at 1,600X1,200 and this was well worth it (the newer can display 2048x1536, but this is smaller than the phosphor dots (well bars - it's Trinitron)). The angular resolution of the naked eye is about 1'; however, some people have sharper vision than that. |
optimum viewing distance vs screen size - SD & HD
R. Mark Clayton wrote:
My desk PC has two 21" CRT screens at 1,600X1,200 and this was well worth it (the newer can display 2048x1536, but this is smaller than the phosphor dots (well bars - it's Trinitron)). Nice, but it's worth bearing in mind that watching TV on a small screen at close range is by no means equivalent to watching TV on a large screen at a proportionally greater distance. I think the reason for this is partly because most programme content is shot with a camera-to-subject distance which is greater than typical TV viewing distances, so a bigger screen image at a larger distance appears more natural and life-like to the eye and brain, and partly because the eyes have to work harder to converge and focus on a near object. The lens muscles are relaxed when the eyes are focussed on the far point. I became aware of this effect when testing my stereoscopic viewing system with 2D images. In the extreme case, the images are only 15 cm from the eyes but strong reading glasses are used so that the images are in focus when the eyes are relaxed and focussed on the far point. In addition, by using two screens, the image path for the two eyes is split, and the convergence can be adjusted for "parallel" viewing with the eyes again relaxed and looking into the distance. The result is a virtual screen image of indeterminate size located at "infinity". The effect is cinematic, and very different to watching video on a small screen at a short viewing distance. The angular resolution of the naked eye is about 1'; however, some people have sharper vision than that. |
| All times are GMT +1. The time now is 09:22 PM. |
|
Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
HomeCinemaBanter.com